Re: Web framework
Renato Barbosa Pim Pereira writes: > I'm thinking of porting a Python application that uses numpy for web, > basically would like to upload a user-defined data, perform the > calculations with numpy and plot charts with the general structure of > a site such as a blog for example The “default” option is Django https://www.djangoproject.com/>, but that only means there is a lot of community support for it — there are plenty of other good options, as you've noticed. > I have studied a bit of django and web2py, but I wonder if there is > some better framework? or how to choose a particular framework over > another? This is a very vague question. You're best placed to know what it is you want. What have you learned from your attempts to implement the site already? What has gone wrong, what do you need that you would expect from a better framework? -- \“Program testing can be a very effective way to show the | `\presence of bugs, but is hopelessly inadequate for showing | _o__) their absence.” —Edsger W. Dijkstra | Ben Finney -- https://mail.python.org/mailman/listinfo/python-list
Re: Dvalve! we called the heart of outsourcing world.
On Friday, 9 April 2010 23:14:16 UTC+2, Dvalve.com wrote: > Dvalve.com is an online talent workplace that helps companies hire and > manage professionals online to get work done and grow their > businesses. Dvalve matches employers with a ready and qualified > workforce and rated, tested professionals with technical, marketing > and business skills. Dvalve also provides the online workplace and > tools to manage and pay remote professionals and teams online. > Contractors and service providers around the world use Dvalve to meet > employers and get paid for delivering great results.VISIT WWW.DVALVE.COM > FOR YOUR OUTSOURCE & BUSINESS NEEDS, SEE HOW FAST YOUR JOBS DONE WITH > QUALITY AND SECURITY.Dvalve a real virtual outsourcing ThinkTank. > Waiting for your valued participation.DVALVE TEAM Welcomes > freelancers, web designers. programmers, developers, designers, > business guys and all corporate and IT peoples TO WORK WITH US Please > Register as per your skills and wait for our Interview call. You can > register as a Service Provider or as a Buyer Account. Buyer will get > tie up Offers and providers will catch Jobs!. > One dice for all. > Regards > Dvalve Team > www.dvalve.com You know your website doesn't work? Do you have any contact details -- https://mail.python.org/mailman/listinfo/python-list
What's wrong?New hand.chapter7/8 webapp -No such CGI script
My webapp is once good to use. Now I do not know what happened. It can not work.
when i type http://localhost:8080/cgi-bin/generate_list.py ,
http://localhost:8080/cgi-bin/generate_timing_data.py, or anything after
cgi-bin in my chrome. It all turns out like Message: No such CGI script
('/cgi-bin/generate_timing_data.py'). Error code explanation: 404 - Nothing
matches the given URI.
I even download the webapp on http://www.headfirstlabs.com/books/hfpython/
Still it does not work.
(you can download the app on the website,that is chapter 8. And the app is in
file webapp-chapter8)
Thank you!
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Re: Traceback when using multiprocessing, less than helpful?
On 22/11/2013 03:57, John Ladasky wrote: ...Richard submits his "hack" (his description) to Python 3.4 which pickles and passes the string. When time permits, I'll try it out. Or maybe I'll wait, since Python 3.4.0 is still in alpha. FTR beta 1 is due this Saturday 24/11/2013. -- Python is the second best programming language in the world. But the best has yet to be invented. Christian Tismer Mark Lawrence -- https://mail.python.org/mailman/listinfo/python-list
Web Page Parsing/Downloading
Hi. I'm self taught at Python and I used http://www.codecademy.com/ to learn
which was great help i must say but now, I'm attempting it all on my own and
need a little help?
I have three scripts and this is what I'm trying to do with them;
Download from webpage
Parse Links from Page
Output summary of total links
Format a list of matched links
Parse and Print Email addresses
Crach Hash Passwords
Exception Handling
Parsing and Print links to image files/.doc
Save file into specified folder and alert when files don't save
Can anyone help because I've become a little stuck? None of the scripts are
running for me and I can't see where I'm having issues
WebPage script;
import sys, urllib
def getWebpage(url):
print '[*] getWebpage()'
url_file = urllib.urlopen(url)
page = url_file.read()
return page
def main():
sys.argv.append('http://www.funeralformyfat.tumblr.com')
if len(sys.argv) != 2:
print '[-] Usage: webpage_get URL'
return
print getWebpage(sys.argv[1])
if __name__ == '__main__':
main()
getLinks
def print_links(page):
print '[*] print_links()'
links = re.findall(r'\http://www.funeralformyfat.tumblr.com')
if len(sys.argv) != 2:
print '[-] Usage: webpage_getlinks URL'
return
page = webpage_get.wget(sys.argv[1])
print_links(page)
from os.path import join
directory = join('/home/', y, '/newdir/')
file_name = url.split('/')[-1]
file_name = join(directory, file_name)
if __name__ == '__main__':
main()
getParser
import md5
oldpasswd_byuser=str("tom")
oldpasswd_db="sha1$c60da$1835a9c3ccb1cc436ccaa577679b5d0321234c6f"
opw= md5.new(oldpasswd_byuser)
#opw= md5.new(oldpasswd_byuser).hexdigest()
if(opw == oldpasswd_db):
print "same password"
else:
print "Invalid password"
from email.parser import Parser
#headers = Parser().parse(open(messagefile, 'r'))
headers = Parser().parsestr('From: \n'
'To: \n'
'Subject: Test message\n'
'\n'
'Body would go here\n')
print 'To: %s' % headers['to']
print 'From: %s' % headers['from']
print 'Subject: %s' % headers['subject']
Thanks for any help!
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Re: Web framework
Hi, > I'm thinking of porting a Python application that uses numpy for web, > basically would like to upload a user-defined data, perform the > calculations with numpy and plot charts with the general structure of a > site such as a blog for example, I have studied a bit of django and > web2py, but I wonder if there is some better framework? or how to choose > a particular framework over another? I've recently worked on the same kind of Python web application. I have a preference for microframework, here is an explanation of what does micro mean: http://flask.pocoo.org/docs/foreword/#what-does-micro-mean And among all the good microframework available, I like Flask: http://flask.pocoo.org It has an excellent documentation, it is based on two great libraries: Werkzeug and Jinja2, it has an extenstion system, it has active an has a growning communinty ... and its written by Armin Ronacher! Hope it helps. David > > Since now, thanks > -- > https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
Method chaining
A frequently missed feature is the ability to chain method calls: x = [] x.append(1).append(2).append(3).reverse().append(4) => x now equals [3, 2, 1, 4] This doesn't work with lists, as the methods return None rather than self. The class needs to be designed with method chaining in mind before it will work, and most Python classes follow the lead of built-ins like list and have mutator methods return None rather than self. Here's a proof-of-concept recipe to adapt any object so that it can be used for chaining method calls: class chained: def __init__(self, obj): self.obj = obj def __repr__(self): return repr(self.obj) def __getattr__(self, name): obj = getattr(self.obj, name) if callable(obj): def selfie(*args, **kw): # Call the method just for side-effects, return self. _ = obj(*args, **kw) return self return selfie else: return obj chained([]).append(1).append(2).append(3).reverse().append(4) => returns [3, 2, 1, 4] Tested, and works, in CPython 2.4 through 2.7, 3.2 and 3.3, Jython 2.5, and IronPython 2.6. See here for further discussion of the limitations: http://code.activestate.com/recipes/578770-method-chaining/ -- Steven -- https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
On Fri, Nov 22, 2013 at 10:26 PM, Steven D'Aprano wrote: > if callable(obj): > def selfie(*args, **kw): > # Call the method just for side-effects, return self. > _ = obj(*args, **kw) > return self > return selfie > else: > return obj Nice piece of magic. One limitation not mentioned is that this completely destroys the chance to have a method return anything _other than_ self. Since this is intended for Python's convention of "mutators return None", I'd be inclined to check for a None return, though that might still have some false positives. def selfie(*args, **kw): # Call the method for side-effects, return self if it returns None. _ = obj(*args, **kw) if _ is None: return self return _ return selfie Either that, or manually identify a set of methods to wrap, which could possibly be done fairly cleanly with a list of names passed to __init__. That'd be more work, though. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Web Page Parsing/Downloading
On Fri, Nov 22, 2013 at 9:10 PM, TheRandomPast wrote: > Can anyone help because I've become a little stuck? None of the scripts are > running for me and I can't see where I'm having issues I'm rather lost in what you're trying to accomplish here. The first thing to do would be to separate out your three scripts and just look at one at a time; then cut each one down to just what it really needs to be doing. Once you've done that, you'll have a simple example - see http://sscce.org/ for tips on that - and you can figure out what it's doing wrong. If you can't figure it out on your own, the short example will be far more suitable for posting here, along with its error backtrace (if it's throwing one), than a more verbose program listing. Two general points of advice. Firstly, if you're just starting out, I strongly recommend you use Python 3 instead of Python 2. All sorts of things have been improved, and it's far easier to learn on the new version than to learn on the old and then have to change your habits later. And secondly, please read this and take note: https://wiki.python.org/moin/GoogleGroupsPython - otherwise, you'll find that a lot of people don't want to see your post. Best would be to avoid Google Groups altogether, as it's very approximately the worst newsgroup client I've ever seen posts from. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
Steven D'Aprano wrote: > A frequently missed feature is the ability to chain method calls: > > x = [] > x.append(1).append(2).append(3).reverse().append(4) > => x now equals [3, 2, 1, 4] > > > This doesn't work with lists, as the methods return None rather than > self. The class needs to be designed with method chaining in mind before > it will work, and most Python classes follow the lead of built-ins like > list and have mutator methods return None rather than self. > > Here's a proof-of-concept recipe to adapt any object so that it can be > used for chaining method calls: > > > class chained: > def __init__(self, obj): > self.obj = obj > def __repr__(self): > return repr(self.obj) > def __getattr__(self, name): > obj = getattr(self.obj, name) > if callable(obj): > def selfie(*args, **kw): > # Call the method just for side-effects, return self. > _ = obj(*args, **kw) > return self > return selfie > else: > return obj > > > chained([]).append(1).append(2).append(3).reverse().append(4) > => returns [3, 2, 1, 4] > > > Tested, and works, in CPython 2.4 through 2.7, 3.2 and 3.3, Jython 2.5, > and IronPython 2.6. > > See here for further discussion of the limitations: > > http://code.activestate.com/recipes/578770-method-chaining/ Here's my take: class Chained(object): def __init__(self, value, method=None): self.value = value self.method = method def __call__(self, *args, **kw): result = self.method(*args, **kw) if result is None: result = self.value return Chained(result) def __getattr__(self, name): return Chained(self.value, getattr(self.value, name)) if __name__ == "__main__": print(Chained([]).append(1).append(2).append(3).reverse().append(4).value) print(Chained([]).append(1).extend([2,1,1]).count(1).value) These things are nice to write as long as you omit the gory details, but personally I don't want to see the style it favours in my or other people's code. -- https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
On 11/22/2013 6:26 AM, Steven D'Aprano wrote: A frequently missed feature is the ability to chain method calls: x = [] x.append(1).append(2).append(3).reverse().append(4) => x now equals [3, 2, 1, 4] This doesn't work with lists, as the methods return None True for the 7 pure mutation methods but not for .copy, .count, .index, and .pop. The last both mutates and returns. -- Terry Jan Reedy -- https://mail.python.org/mailman/listinfo/python-list
Special Issue on "Software Development Tools" - High Visibility & Fast Publication
This message was sent to [[email protected]]. Unsubscribe If you cannot read it, please click here. Special Issue on "Software Development Tools" Submission Deadline: February 19th, 2014Dear ,Journal of Software Engineering and Applications (JSEA) is seeking papers for the upcoming special issue on "Software Development Tools". We would like to invite contributors like you to submit papers that may shed some light on this issue through our Paper Submission System.About Our JournalJSEA is an international, double-blind, peer-reviewed and open-access journal with both print and online versions. For more information about the journal, please visit: http://www.scirp.org/journal/jsea.Aims & Scope (not limited to): • Software requirements tools • Software construction tools • Software maintenance tools • Software configure management tools • Software project management tools • Software quality toolsOther Special Issues in JSEA • Cloud Computing (Submission Deadline: November 29th, 2013) • Programming Languages (Submission Deadline: January 23rd, 2014) • Software Analysis and Testing (Submission Deadline: March 5th, 2014) >> MoreGuest EditorProf. Janche Sang (Cleveland State University, USA) JSEA Editorial Office E-mail: [email protected] Place of Public Relation: Scientific Research Publishing Inc., P. O. BOX 54821, Irvine CA 92619-4821, USA. Place of Customer Service: Building 5, Headquarters Space of Optical Valley, Tangxun Lake North Street 38#, East Lake High-Tech Development Zone, Wuhan 430223, Hubei Province, China.-- https://mail.python.org/mailman/listinfo/python-list
Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
Hello Sir/Mam, Could you please help me with my current research ? Am implementing the concept in python language. My doubts are : 1) Is it possible to Retrieve the address of a variable in python ? 2) Is it possible to Delete the Address of the Variable and create a new dynamic address inside the compiler/interpreter itself ? 3) Is it easy to find the Binary equivalence of a given Alphanumeric String ? 4) Is it possible to count the number of 1's in the Binary equivalence ? Could you PLEASE provide me with the codes (codes only for the asked queries) ? Your reply counts a lot for me and my research ! I love to explore more in python. Awaiting for your Response (Please reply ASAP). Best, Bharath (+91 9025338332) -- https://mail.python.org/mailman/listinfo/python-list
Re: Having trouble setting up an extremely simple server...
In article <[email protected]>, Steven D'Aprano wrote: > There are all sorts of things that you can do that don't make your code > "wrong" but do make it difficult to deal with. Why stop with semi-colons? > > import socket; pass; pass; pass; pass; pass; > serverReady = ((True is True) is True) is True) is True); > serverSock = socket . \ > socket( > socket . \ >AF_INET\ > , \ > socket.\ > SOCK_STREAM\ >) \ > ; Steve, you're just worried about how readable some Python code is. All I can say to that is #firstworldproblem. There's bigger issues at stake here. One thing to be aware of is that semicolons are valuable on the world punctuation spot market. Somewhere, right now, in Greenwich or Stamford, or maybe Tribeca, in some hedge-fund sweat shop, there's a C++ programmer who can't afford to write a for(;;) loop because he doesn't have enough semicolons. Why? Because the world punctuation markets can't handle the added buy-side pressure from new Python programmers using the wrong punctuation. Also, every semicolon we save can be broken down and res-used as TWO decimal points! The Americans use the top part, most other places use the bottom part. It's like a punctuation breeder reactor. One piece goes in, and two come out. So, really. Cut it out with the semicolons. If you won't do it for us, think of the hedge-fund coders. -- https://mail.python.org/mailman/listinfo/python-list
Help me to print to screen as well as log
I want that print "hello" should appear on screen as well as get saved in a log file. How can I accomplish this? -- https://mail.python.org/mailman/listinfo/python-list
Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
In article ,
Bharath Kummar wrote:
> Could you please help me with my current research ? Am implementing the
> concept in python language.
> My doubts are :
[Note to readers of American/British English; Indian English uses
"doubt" the same way we would use "question"]
> 1) Is it possible to Retrieve the address of a variable in python ?
No. One of the fundamental concepts of Python is that it completely
hides the physical memory. Sure, at some point, when you write
x = 42
it allocates some piece of memory and puts the integer 42 into it, but
all those details are hidden from you (and are implementation specific).
> 3) Is it easy to find the Binary equivalence of a given Alphanumeric
> String ?
I think what you're talking about is the ord() function. Given a single
character (i.e. a string of length 1), it returns the unicode value for
that character. Thus:
>>> ord('X')
88
You could iterate over the characters in a string to find that for each
one:
>>> [ord(c) for c in "My string"]
[77, 121, 32, 115, 116, 114, 105, 110, 103]
> 4) Is it possible to count the number of 1's in the Binary equivalence ?
This is starting to sound like a homework problem, or possibly an
interview question :-)
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Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
On Fri, 22 Nov 2013 18:22:29 +0530, Bharath Kummar wrote:
> 1) Is it possible to Retrieve the address of a variable in python ?
No. Variables in Python are not at fixed addresses, like in Pascal or C,
they are names in a namespace.
You can read this post for some more information about the difference
between C variables and Python variables, and calling conventions across
different languages:
https://mail.python.org/pipermail/tutor/2010-December/080505.html
It's a long post, but to summarise the part about variables:
In languages like Pascal or C, the compiler keeps a table mapping
variable names to fixed memory addresses, like this:
Variable Address
===
x 10234
y 10238
z 10242
The command "x = 42" stores the value 42 into memory address 10234. If
you ask the compiler for the address of x, it can say 10234. That's how
variables work in languages like Pascal, C, Fortran, and similar.
With the Pascal or C style variable, the variable address exists even
before you give it a value.
But languages like Python don't work that way. There is no table of
variable:address available to the compiler, and variables don't have an
address. Python's variables are *name bindings*, not fixed memory
addresses. The Python runtime keeps a global dictionary which maps names
to their values:
{'x': ,
'y': ,
'z': ,
}
The general name for this is "namespace". In Python you can access the
global namespace with the globals() function, and a read-only copy of the
local namespace with the locals() function.
Entries in the namespace cannot be blank. So names don't exist before
they are bound to a value.
> 2)
> Is it possible to Delete the Address of the Variable and create a new
> dynamic address inside the compiler/interpreter itself ?
I don't understand this question.
Since variables don't have addresses, you can't delete what doesn't exist.
> 3) Is it easy
> to find the Binary equivalence of a given Alphanumeric String ?
Which binary equivalence are you referring to? Again, I don't understand
your question. I can do this:
py> astring = "1234"
py> int(astring).to_bytes(4, 'big')
b'\x00\x00\x04\xd2'
py> int(astring).to_bytes(4, 'little')
b'\xd2\x04\x00\x00'
Or I can do this:
py> astring = "Alpha1234 δθЖ∞"
py> astring.encode('utf-8')
b'Alpha1234 \xce\xb4\xce\xb8\xd0\x96\xe2\x88\x9e'
Or I can do this:
py> import binascii
py> binascii.hexlify(b'Hello World!')
b'48656c6c6f20576f726c6421'
And many other string -> binary equivalences. Which ones did you have in
mind?
> 4) Is it possible to count the number of 1's in the Binary equivalence
> ?
Of course. First decide which binary equivalence you want, then decide
what you mean by "count the number of 1s" (do you mean the byte with
value 1, or the ASCII code for 1, or the bit 1?), then count them.
> Could you PLEASE provide me with the codes (codes only for the asked
> queries) ?
If you explain your question in more detail, we can give more detailed
answers.
--
Steven
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Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
On Friday, November 22, 2013 6:22:29 PM UTC+5:30, Bharath Kummar wrote: > Hello Sir/Mam, > Could you please help me with my current research ? Am implementing the > concept in python language. > My doubts are : > 1) Is it possible to Retrieve the address of a variable in python ? > 2) Is it possible to Delete the Address of the Variable and create a new > dynamic address inside the compiler/interpreter itself ? > 3) Is it easy to find the Binary equivalence of a given Alphanumeric String ? > 4) Is it possible to count the number of 1's in the Binary equivalence ? > Could you PLEASE provide me with the codes (codes only for the asked queries) > ? > Your reply counts a lot for me and my research ! I love to explore more in > python. 1) id will give you addresses. Except that - not portable ie not guaranteed to be a m/c address - its of an object not a variable - if you are thinking C, its mostly useless 2) del will delete objects -- like free in C Except that like above, thinking in C will cause more problems than it solves 3,4 I cant make out what you mean -- https://mail.python.org/mailman/listinfo/python-list
Re: Help me to print to screen as well as log
On Fri, 22 Nov 2013 05:51:21 -0800, Himanshu Garg wrote:
> I want that print "hello" should appear on screen as well as get saved
> in a log file.
>
> How can I accomplish this?
print "hello"
logfile.write("hello\n")
Does that satisfy your need? If not, please explain in more detail what
you are trying to do, what you have already tried, and what happened when
you tried it.
--
Steven
--
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Re: Having trouble setting up an extremely simple server...
On Sat, Nov 23, 2013 at 12:41 AM, Roy Smith wrote: > Also, every semicolon we save can be broken down and res-used as TWO > decimal points! The Americans use the top part, most other places use > the bottom part. It's like a punctuation breeder reactor. One piece > goes in, and two come out. That's only the glyph, though. You can't do that with the codepoints - all you end up with is a U+0003 'END OF TEXT' and a U+000B 'LINE TABULATION', useful occasionally but hardly in great demand. No, once you've broken the glyph apart, there's not a lot you can do with the codepoint, and they end up filling the nuclear waste disposal caverns. People keep coming up with schemes for utilizing waste U+0003s, but there's a fundamental problem that text can only end once [1], and all attempts to use U+0003 in commercial use resulted in the premature termination of the text concerned. Of course, the FDA put an immediate stop to that - so expensive to compensate the families of the terminated text - so we're back where we started. ChrisA [1] As is stated in the Holy Writ, Hebrews 9:27: "Just as text is destined to end once, and after that to face judgment, so C strings receive but a single NUL to terminate the strings of many." -- https://mail.python.org/mailman/listinfo/python-list
Re: Help me to print to screen as well as log
Himanshu Garg wrote: > I want that print "hello" should appear on screen as well as get saved in > a log file. > > How can I accomplish this? In Python 3 print() is a function -- you can replace it with a custom function that invokes the original print() twice. In both Python 3 and Python 2 you can redirect sys.stdout/stderr to a custom object with a write() method. If you are actually logging I suggest that you look into the logging package which allows multiple handlers, see http://docs.python.org/3.3/howto/logging.html You will need to replace your print() calls with some_logger.info(message) or similar. -- https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
On Fri, 22 Nov 2013 13:08:03 +0100, Peter Otten wrote: > These things are nice to write as long as you omit the gory details, but > personally I don't want to see the style it favours in my or other > people's code. There's not really a lot of difference between: obj = MyClass() obj.spam() obj.eggs() obj.cheese() and obj = MyClass().spam().eggs().cheese() except the first takes up a lot more vertical space. Chained method calls is idiomatic in some languages. If there is a problem with it, it is that it doesn't make it clear that each method call is being used only for its side-effects, rather than it being a series of distinct objects. But in my opinion that flaw is a very minor one. The nice thing about using an explicit method chaining call rather than building your class to support it by default is that the initial call to the adaptor signals that everything that follows is called only for the side-effects. obj = chained(MyClass()).spam().eggs().cheese() -- Steven -- https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
On Fri, 22 Nov 2013 07:34:53 -0500, Terry Reedy wrote: > On 11/22/2013 6:26 AM, Steven D'Aprano wrote: >> A frequently missed feature is the ability to chain method calls: >> >> x = [] >> x.append(1).append(2).append(3).reverse().append(4) => x now equals [3, >> 2, 1, 4] >> >> >> This doesn't work with lists, as the methods return None > > True for the 7 pure mutation methods but not for .copy, .count, .index, > and .pop. The last both mutates and returns. Yes, that is correct. In this case, the assumption behind the chained adapter is that we don't care about the results of calling those methods, we only care about the mutation they cause. If that's not the case, then chained() isn't for us. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
argparse feature request
I use arparse all the time and find it serves my needs well. One thing I'd
like
to see. In the help message, I'd like to automatically add the default values.
For example, here's one of my programs:
python3 test_freq3.py --help
usage: test_freq3.py [-h] [--size SIZE] [--esnodB ESNODB] [--tau TAU] [--trials
TRIALS]
[--training TRAINING] [--sps SPS] [--si SI] [--alpha ALPHA]
[--range RANGE] [--dfunc {gradient,delay}]
[--mod
{gaussian,qpsk,8psk,16apsk,32apsk,32dlr,64apsk,256apsk}]
[--sym-freq-err SYM_FREQ_ERR] [--calibrate [CALIBRATE]]
optional arguments:
-h, --helpshow this help message and exit
--size SIZE
--esnodB ESNODB, -e ESNODB
--tau TAU, -t TAU
--trials TRIALS
--training TRAINING
--sps SPS
--si SI
--alpha ALPHA
--range RANGE
--dfunc {gradient,delay}
--mod {gaussian,qpsk,8psk,16apsk,32apsk,32dlr,64apsk,256apsk}
--sym-freq-err SYM_FREQ_ERR
--calibrate [CALIBRATE], --with-calibrate [CALIBRATE], --enable-calibrate
[CALIBRATE], --no-calibrate [CALIBRATE], --without-calibrate [CALIBRATE], --
disable-calibrate [CALIBRATE]
What I'd like to see is:
--size SIZE [2000] <<< the default value is displayed
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Re: argparse feature request
On 2013-11-22 14:56, Neal Becker wrote:
I use arparse all the time and find it serves my needs well. One thing I'd like
to see. In the help message, I'd like to automatically add the default values.
For example, here's one of my programs:
python3 test_freq3.py --help
usage: test_freq3.py [-h] [--size SIZE] [--esnodB ESNODB] [--tau TAU] [--trials
TRIALS]
[--training TRAINING] [--sps SPS] [--si SI] [--alpha
ALPHA]
[--range RANGE] [--dfunc {gradient,delay}]
[--mod
{gaussian,qpsk,8psk,16apsk,32apsk,32dlr,64apsk,256apsk}]
[--sym-freq-err SYM_FREQ_ERR] [--calibrate [CALIBRATE]]
optional arguments:
-h, --helpshow this help message and exit
--size SIZE
--esnodB ESNODB, -e ESNODB
--tau TAU, -t TAU
--trials TRIALS
--training TRAINING
--sps SPS
--si SI
--alpha ALPHA
--range RANGE
--dfunc {gradient,delay}
--mod {gaussian,qpsk,8psk,16apsk,32apsk,32dlr,64apsk,256apsk}
--sym-freq-err SYM_FREQ_ERR
--calibrate [CALIBRATE], --with-calibrate [CALIBRATE], --enable-calibrate
[CALIBRATE], --no-calibrate [CALIBRATE], --without-calibrate [CALIBRATE], --
disable-calibrate [CALIBRATE]
What I'd like to see is:
--size SIZE [2000] <<< the default value is displayed
Use formatter_class=argparse.ArgumentDefaultsHelpFormatter
http://docs.python.org/2/library/argparse#argparse.ArgumentDefaultsHelpFormatter
E.g.
[git/mpstack]$ cat print_stacks.py
...
def main():
import argparse
parser = argparse.ArgumentParser(
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('-p', '--percent', action='store_true', help='Show
percentages.')
parser.add_argument('file', help='The sample file.')
...
[git/mpstack]$ python print_stacks.py -h
usage: print_stacks.py [-h] [-p] file
positional arguments:
file The sample file.
optional arguments:
-h, --help show this help message and exit
-p, --percent Show percentages. (default: False)
--
Robert Kern
"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco
--
https://mail.python.org/mailman/listinfo/python-list
Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
On Fri, Nov 22, 2013 at 7:13 AM, rusi wrote: > 2) del will delete objects -- like free in C >Except that like above, thinking in C will cause more problems than it > solves No, del will only delete name bindings. Whether the bound object is also deleted depends on whether it is still referenced, and the timing by which the bound object may be deleted varies between implementations. -- https://mail.python.org/mailman/listinfo/python-list
Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
On 2013-11-22, Steven D'Aprano wrote: > On Fri, 22 Nov 2013 18:22:29 +0530, Bharath Kummar wrote: > >> 1) Is it possible to Retrieve the address of a variable in python ? > > No. Variables in Python are not at fixed addresses, like in Pascal or C, > they are names in a namespace. > > You can read this post for some more information about the difference > between C variables and Python variables, and calling conventions across > different languages: > > https://mail.python.org/pipermail/tutor/2010-December/080505.html > > It's a long post, but to summarise the part about variables: > > In languages like Pascal or C, the compiler keeps a table mapping > variable names to fixed memory addresses, like this: > > Variable Address > === > x 10234 > y 10238 > z 10242 FWIW, that's only true for some sorts of variables. Other variables have an address that is relative to a stack or frame pointer. -- Grant Edwards grant.b.edwardsYow! PEGGY FLEMMING is at stealing BASKET BALLS to gmail.comfeed the babies in VERMONT. -- https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
Steven D'Aprano wrote: > On Fri, 22 Nov 2013 13:08:03 +0100, Peter Otten wrote: > >> These things are nice to write as long as you omit the gory details, but >> personally I don't want to see the style it favours in my or other >> people's code. > > There's not really a lot of difference That cuts both ways ;) > between: > > obj = MyClass() > obj.spam() > obj.eggs() > obj.cheese() > > and > > obj = MyClass().spam().eggs().cheese() > > > except the first takes up a lot more vertical space. I've not yet run short of vertical space ;) > Chained method calls is idiomatic in some languages. Languages with mutable objects? > If there is a problem with it, it is that > it doesn't make it clear that each method call is being used only for its > side-effects, rather than it being a series of distinct objects. But in > my opinion that flaw is a very minor one. > > The nice thing about using an explicit method chaining call rather than > building your class to support it by default is that the initial call to > the adaptor signals that everything that follows is called only for the > side-effects. > > obj = chained(MyClass()).spam().eggs().cheese() obj = MyClass(); obj.spam(); obj.eggs(); obj.cheese() OK, that one is disgusting... Anyway, I'd like to see a sequence of method names taken from actual code that profits from this chaining pattern. -- https://mail.python.org/mailman/listinfo/python-list
Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
On Friday, November 22, 2013 9:13:50 AM UTC-5, rusi wrote: > On Friday, November 22, 2013 6:22:29 PM UTC+5:30, Bharath Kummar wrote: > > Hello Sir/Mam, > > Could you please help me with my current research ? Am implementing the > > concept in python language. > > My doubts are : > > 1) Is it possible to Retrieve the address of a variable in python ? > > 2) Is it possible to Delete the Address of the Variable and create a new > > dynamic address inside the compiler/interpreter itself ? > > 3) Is it easy to find the Binary equivalence of a given Alphanumeric > > String ? > > 4) Is it possible to count the number of 1's in the Binary equivalence ? > > Could you PLEASE provide me with the codes (codes only for the asked > > queries) ? > > Your reply counts a lot for me and my research ! I love to explore more in > > python. > > 1) id will give you addresses. Except that >- not portable ie not guaranteed to be a m/c address >- its of an object not a variable >- if you are thinking C, its mostly useless > > 2) del will delete objects -- like free in C >Except that like above, thinking in C will cause more problems than it > solves Not true: del doesn't delete objects. It merely removes references to objects. Only if the object has no more references is the object deleted. I tried my hand at explaining how names and values work in Python: http://nedbatchelder.com/text/names.html Some people have found it helpful. --Ned. -- https://mail.python.org/mailman/listinfo/python-list
Re: What's wrong?New hand.chapter7/8 webapp -No such CGI script
在 2013年11月22日星期五UTC+8下午4时48分35秒，曹守正写道：
> My webapp is once good to use. Now I do not know what happened. It can not
> work.
>
> when i type http://localhost:8080/cgi-bin/generate_list.py ,
> http://localhost:8080/cgi-bin/generate_timing_data.py, or anything after
> cgi-bin in my chrome. It all turns out like Message: No such CGI script
> ('/cgi-bin/generate_timing_data.py'). Error code explanation: 404 - Nothing
> matches the given URI.
>
> I even download the webapp on http://www.headfirstlabs.com/books/hfpython/
>
> Still it does not work.
>
> (you can download the app on the website,that is chapter 8. And the app is in
> file webapp-chapter8)
>
> Thank you!
在 2013年11月22日星期五UTC+8下午4时48分35秒，曹守正写道：
> My webapp is once good to use. Now I do not know what happened. It can not
> work.
>
> when i type http://localhost:8080/cgi-bin/generate_list.py ,
> http://localhost:8080/cgi-bin/generate_timing_data.py, or anything after
> cgi-bin in my chrome. It all turns out like Message: No such CGI script
> ('/cgi-bin/generate_timing_data.py'). Error code explanation: 404 - Nothing
> matches the given URI.
>
> I even download the webapp on http://www.headfirstlabs.com/books/hfpython/
>
> Still it does not work.
>
> (you can download the app on the website,that is chapter 8. And the app is in
> file webapp-chapter8)
>
> Thank you!
--
https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
Op 22-11-13 16:20, Peter Otten schreef: > Steven D'Aprano wrote: > >> On Fri, 22 Nov 2013 13:08:03 +0100, Peter Otten wrote: >> >>> These things are nice to write as long as you omit the gory details, but >>> personally I don't want to see the style it favours in my or other >>> people's code. >> >> There's not really a lot of difference > > That cuts both ways ;) > >> between: >> >> obj = MyClass() >> obj.spam() >> obj.eggs() >> obj.cheese() >> >> and >> >> obj = MyClass().spam().eggs().cheese() >> >> >> except the first takes up a lot more vertical space. > > I've not yet run short of vertical space ;) Really? Then you must write only very short programs. Me I continuously run out of vertical space. That is why I need to use such tools as scroll bars. -- Antoon Pardon. -- https://mail.python.org/mailman/listinfo/python-list
Re: Help me to print to screen as well as log
On 22/11/2013 14:15, Steven D'Aprano wrote:
On Fri, 22 Nov 2013 05:51:21 -0800, Himanshu Garg wrote:
I want that print "hello" should appear on screen as well as get saved
in a log file.
How can I accomplish this?
print "hello"
logfile.write("hello\n")
Does that satisfy your need? If not, please explain in more detail what
you are trying to do, what you have already tried, and what happened when
you tried it.
Fancy wasting vertical space like that, if you use a semi-colon you can
save a whole lot of it like this
print "hello";logfile.write("hello\n") # :)
--
Python is the second best programming language in the world.
But the best has yet to be invented. Christian Tismer
Mark Lawrence
--
https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
On Fri, 22 Nov 2013 16:20:03 +0100, Peter Otten wrote: > Steven D'Aprano wrote: > >> On Fri, 22 Nov 2013 13:08:03 +0100, Peter Otten wrote: >> >>> These things are nice to write as long as you omit the gory details, >>> but personally I don't want to see the style it favours in my or other >>> people's code. >> >> There's not really a lot of difference > > That cuts both ways ;) Actually, I was wrong. See below. >> between: >> >> obj = MyClass() >> obj.spam() >> obj.eggs() >> obj.cheese() >> >> and >> >> obj = MyClass().spam().eggs().cheese() >> >> >> except the first takes up a lot more vertical space. > > I've not yet run short of vertical space ;) However, here is a real difference: # With chaining thing = func(MyClass().spam().eggs().cheese(), MyClass().aardvark(), OtherClass().fe().fi().fo().fum(), ) do_stuff_with(thing) versus: # Without chaining temp1 = MyClass() temp1.spam() temp1.eggs() temp1.cheese() temp2 = MyClass() temp2.aardvark() temp3 = OtherClass() temp3.fe() temp3.fi() temp3.fo() temp3.fum() thing = func(temp1, temp2, temp3) do_stuff_with(thing) In this case the chained version doesn't obscure the intention of the code anywhere near as much as the unchained version and its plethora of temporary variables. >> Chained method calls is idiomatic in some languages. > > Languages with mutable objects? Yes. It's a "Design Pattern" applicable to any language with mutator methods. Here are three examples in C#, Java and Ruby: http://mrbool.com/fluent-interface-and-method-chaining-a-good-programming-approach/26365 http://www.infoq.com/articles/internal-dsls-java http://blog.jayfields.com/2008/03/ruby-replace-temp-with-chain.html although in fairness I wouldn't call it idiomatic in C# or Java. Ruby 1.9 even added a new method to Object, tap, specifically to allow chaining of methods, which itself was copied from Ruby-On-Rails' "returning" helper. So I think it's fair to say that method chaining for mutation is idiomatic in Ruby. http://www.seejohncode.com/2012/01/02/ruby-tap-that/ http://blog.moertel.com/posts/2007-02-07-ruby-1-9-gets-handy-new-method-object-tap.html This idea goes back to Smalltalk, and is essentially just a pipeline. Hardly something weird. http://en.wikipedia.org/wiki/Method_chaining (Technically, if the methods return self rather than None, it's method cascading. Chaining is any sequence of method calls, whether they return self or something else.) Dart includes syntax for method cascades, which I'm told looks like this: x = SomeClass() ..spam() ..eggs() ..cheese() The technique also comes with the blessing of Martin Fowler, where it is an important part of fluent interfaces: http://martinfowler.com/bliki/FluentInterface.html Quote: "The common convention in the curly brace world is that modifier methods are void, which I like because it follows the principle of CommandQuerySeparation. This convention does get in the way of a fluent interface, so I'm inclined to suspend the convention for this case." And last but not least, if you want to go all the way down to the lambda calculus and combinator theory, my "selfie" adapter function is just a form of the K-combinator (a.k.a. the Kestrel). So there's a deep and powerful mathematical pedigree to the idea, if that matters. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
Why pickling (was: Traceback when using multiprocessing)
On Thursday, November 21, 2013 8:24:05 PM UTC-8, Chris Angelico wrote: > Oh, that part's easy. Let's leave the multiprocessing module out of it > for the moment; imagine you spin up two completely separate instances > of Python. Create some object in one of them; now, transfer it to the > other. How are you going to do it? For what definition of "completely separate"? If I have two instances of the same version of the Python interpreter running on the same hardware, and the same operating system, I expect I would just copy a block of memory from one interpreter to the other, and then write some new pointers. That kind of data sharing has to be the most common kind. It's also the simplest. I understand that pickling allows sharing of Python objects between Python interpreters even if those interpreters run on different CPU's with different memory architecture, different operating systems, etc. It just seems like overkill to me to use pickling in the simple case. -- https://mail.python.org/mailman/listinfo/python-list
Re: Dvalve! we called the heart of outsourcing world.
On Friday, November 22, 2013 12:44:38 AM UTC-8, [email protected] wrote: > You know your website doesn't work? > Do you have any contact details You're responding to a (spam!) post which is dated April 9, 2010 -- two and a half years ago. -- https://mail.python.org/mailman/listinfo/python-list
Re: argparse feature request
Robert Kern wrote:
> On 2013-11-22 14:56, Neal Becker wrote:
>> I use arparse all the time and find it serves my needs well. One thing I'd
>> like
>> to see. In the help message, I'd like to automatically add the default
>> values.
>>
>> For example, here's one of my programs:
>>
>> python3 test_freq3.py --help
>> usage: test_freq3.py [-h] [--size SIZE] [--esnodB ESNODB] [--tau TAU]
>> [--trials TRIALS]
>> [--training TRAINING] [--sps SPS] [--si SI] [--alpha
>> [ALPHA] --range RANGE] [--dfunc {gradient,delay}]
>> [--mod
>> {gaussian,qpsk,8psk,16apsk,32apsk,32dlr,64apsk,256apsk}]
>> [--sym-freq-err SYM_FREQ_ERR] [--calibrate [CALIBRATE]]
>>
>> optional arguments:
>>-h, --helpshow this help message and exit
>>--size SIZE
>>--esnodB ESNODB, -e ESNODB
>>--tau TAU, -t TAU
>>--trials TRIALS
>>--training TRAINING
>>--sps SPS
>>--si SI
>>--alpha ALPHA
>>--range RANGE
>>--dfunc {gradient,delay}
>>--mod {gaussian,qpsk,8psk,16apsk,32apsk,32dlr,64apsk,256apsk}
>>--sym-freq-err SYM_FREQ_ERR
>>--calibrate [CALIBRATE], --with-calibrate [CALIBRATE], --enable-calibrate
>> [CALIBRATE], --no-calibrate [CALIBRATE], --without-calibrate [CALIBRATE], --
>> disable-calibrate [CALIBRATE]
>>
>> What I'd like to see is:
>>
>> --size SIZE [2000] <<< the default value is displayed
>
> Use formatter_class=argparse.ArgumentDefaultsHelpFormatter
>
>
http://docs.python.org/2/library/argparse#argparse.ArgumentDefaultsHelpFormatter
>
> E.g.
>
> [git/mpstack]$ cat print_stacks.py
> ...
> def main():
> import argparse
> parser = argparse.ArgumentParser(
> formatter_class=argparse.ArgumentDefaultsHelpFormatter)
> parser.add_argument('-p', '--percent', action='store_true', help='Show
> percentages.')
> parser.add_argument('file', help='The sample file.')
> ...
>
> [git/mpstack]$ python print_stacks.py -h
> usage: print_stacks.py [-h] [-p] file
>
> positional arguments:
>file The sample file.
>
> optional arguments:
>-h, --help show this help message and exit
>-p, --percent Show percentages. (default: False)
>
Thanks! Almost perfect. Problem is, I don't usually bother to add help='help
me' options. It seems that ArgumentDefaultsHelpFormatter doesn't do anything
unless help='blah' option is used. Not sure what to do about that. Since
python test_freq3.py -h
produces useful messages without my adding help=... everywhere, it'd be nice
if ArgumentDefaultsHelpFormatter would work here.
--
https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
Steven D'Aprano pearwood.info> writes: > # With chaining > thing = func(MyClass().spam().eggs().cheese(), > MyClass().aardvark(), > OtherClass().fe().fi().fo().fum(), > ) > do_stuff_with(thing) > > versus: > > # Without chaining > temp1 = MyClass() > temp1.spam() > temp1.eggs() > temp1.cheese() > temp2 = MyClass() > temp2.aardvark() > temp3 = OtherClass() > temp3.fe() > temp3.fi() > temp3.fo() > temp3.fum() > thing = func(temp1, temp2, temp3) > do_stuff_with(thing) > Another use case might be in comprehensions and generator expressions ?? thing = [MyClass().spam().eggs(x).cheese() for x in sequence] where you can't use all those temporary assignments. Best, Wolfgang -- https://mail.python.org/mailman/listinfo/python-list
Re: argparse feature request
On 2013-11-22 16:52, Neal Becker wrote: Robert Kern wrote: On 2013-11-22 14:56, Neal Becker wrote: I use arparse all the time and find it serves my needs well. One thing I'd like to see. In the help message, I'd like to automatically add the default values. What I'd like to see is: --size SIZE [2000] <<< the default value is displayed Use formatter_class=argparse.ArgumentDefaultsHelpFormatter http://docs.python.org/2/library/argparse#argparse.ArgumentDefaultsHelpFormatter Thanks! Almost perfect. Problem is, I don't usually bother to add help='help me' options. It seems that ArgumentDefaultsHelpFormatter doesn't do anything unless help='blah' option is used. Not sure what to do about that. Since python test_freq3.py -h produces useful messages without my adding help=... everywhere, it'd be nice if ArgumentDefaultsHelpFormatter would work here. Patches are welcome, I am sure. Implement a HelpFormatter that does what you want. _format_action() is where the relevant logic is. Try something like this, and modify to suit. class BeckerDefaultFormatter(argparse.ArgumentDefaultsHelpFormatter): def _format_action(self, action): monkeypatched = False if action.default is not None and action.help is None: # Trick the default _format_action() method into writing out # the defaults. action.help = ' ' monkeypatched = True formatted = super(BeckerDefaultFormatter, self)._format_action(action) if monkeypatched: action.help = None return formatted -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco -- https://mail.python.org/mailman/listinfo/python-list
Re: Having trouble setting up an extremely simple server...
- Original Message - > Please help! I'm very > new to networking, but I've been using Python for a while now, just > recent;y getting into networking, trying to get things down. Hi, Nothing wrong with diving into the muddy waters of network programming. If you like blue lagoons like me, there's a lot of high level remote protocols/network engines/web frameworks that allow you to code applications without caring about networking code. Most of to more complex frameworks provide a simple way to write simple servers and clients. Be sure to check them out before writing your own (except for educational purpose) JM -- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. -- https://mail.python.org/mailman/listinfo/python-list
Re: Method chaining
Wolfgang Maier biologie.uni-freiburg.de> writes: > > Steven D'Aprano pearwood.info> writes: > > > # With chaining > > thing = func(MyClass().spam().eggs().cheese(), > > MyClass().aardvark(), > > OtherClass().fe().fi().fo().fum(), > > ) > > do_stuff_with(thing) > > > > versus: > > > > # Without chaining > > temp1 = MyClass() > > temp1.spam() > > temp1.eggs() > > temp1.cheese() > > temp2 = MyClass() > > temp2.aardvark() > > temp3 = OtherClass() > > temp3.fe() > > temp3.fi() > > temp3.fo() > > temp3.fum() > > thing = func(temp1, temp2, temp3) > > do_stuff_with(thing) > > > > Another use case might be in comprehensions and generator expressions ?? > > thing = [MyClass().spam().eggs(x).cheese() for x in sequence] > > where you can't use all those temporary assignments. > > Best, > Wolfgang > > Thinking about this, you could define __call__ for your chained class to return the wrapped object: class chained: def __init__(self, obj): self.obj = obj def __repr__(self): return repr(self.obj) def __getattr__(self, name): obj = getattr(self.obj, name) if callable(obj): def selfie(*args, **kw): # Call the method just for side-effects, return self. _ = obj(*args, **kw) return self return selfie else: return obj def __call__(self): return self.obj This would encourage its localized use on the fly as in: thing = [MyClass().spam().eggs(x).cheese()() for x in sequence] where the intention probably would be to generate a list of lists (or other mutable objects), not of objects of class chained. Localizing the use of chained also seems like a good idea to me as I do share Peter's worries about coding style, while I also agree with you that such a class comes in handy from time to time. -- https://mail.python.org/mailman/listinfo/python-list
Re: argparse feature request
Robert Kern wrote: > On 2013-11-22 16:52, Neal Becker wrote: >> Robert Kern wrote: >> >>> On 2013-11-22 14:56, Neal Becker wrote: I use arparse all the time and find it serves my needs well. One thing I'd like to see. In the help message, I'd like to automatically add the default values. > What I'd like to see is: --size SIZE [2000] <<< the default value is displayed >>> >>> Use formatter_class=argparse.ArgumentDefaultsHelpFormatter >>> >>> >>> http://docs.python.org/2/library/argparse#argparse.ArgumentDefaultsHelpFormatter > >> Thanks! Almost perfect. Problem is, I don't usually bother to add >> help='help >> me' options. It seems that ArgumentDefaultsHelpFormatter doesn't do anything >> unless help='blah' option is used. Not sure what to do about that. Since >> python test_freq3.py -h >> produces useful messages without my adding help=... everywhere, it'd be nice >> if ArgumentDefaultsHelpFormatter would work here. > > Patches are welcome, I am sure. Implement a HelpFormatter that does what you > want. _format_action() is where the relevant logic is. Try something like > this, and modify to suit. > > > class BeckerDefaultFormatter(argparse.ArgumentDefaultsHelpFormatter): > > def _format_action(self, action): > monkeypatched = False > if action.default is not None and action.help is None: > # Trick the default _format_action() method into writing out > # the defaults. > action.help = ' ' > monkeypatched = True > formatted = super(BeckerDefaultFormatter, > self)._format_action(action) if monkeypatched: > action.help = None > return formatted > Thanks! Seems to work great. It gave reasonable output for both case where I include help=... and also without. I have no idea how that above code works, but I guess as long as it works... -- https://mail.python.org/mailman/listinfo/python-list
Re: How to install pip for python3 on OS X?
On Nov 20, 2013, at 6:01 AM, Mark Lawrence wrote: > On 20/11/2013 06:55, Travis Griggs wrote: >> OSX (Mavericks) has python2.7 stock installed. But I do all my own >> personal python stuff with 3.3. I just flushed my 3.3.2 install and >> installed the new 3.3.3. So I need to install pyserial again. > > Just idle curiosity but why do you have to do this? On Windows I just whack > 3.3.3 over the top of 3.3.2, job done. I think in this case, it was a chance to clean house, and maybe up the “tools” game (e.g. use pip) instead of what I had been doing. So you’re correct. The flushing of 3.3.2 was more that I *wanted* to, instead of *needing* to. (aside. I do not use GoogleGroups, but have been accused of somehow sending email that looks like I do. Does this email look like that?) -- https://mail.python.org/mailman/listinfo/python-list
Re: How to install pip for python3 on OS X?
On Nov 19, 2013, at 11:27 PM, Ned Deily wrote: > In article <[email protected]>, > Travis Griggs wrote: > >> OSX (Mavericks) has python2.7 stock installed. But I do all my own personal >> python stuff with 3.3. I just flushed my 3.3.2 install and installed the new >> 3.3.3. So I need to install pyserial again. I can do it the way I've done it >> before, which is: >> >> Download pyserial from pypi >> untar pyserial.tgz >> cd pyserial >> python3 setup.py install >> But I'd like to do like the cool kids do, and just do something like pip3 >> install pyserial. But it's not clear how I get to that point. And just that >> point. Not interested (unless I have to be) in virtualenv >> yet.- > > http://www.pip-installer.org/en/latest/installing.html > > # download and install setuptools > curl -O https://bitbucket.org/pypa/setuptools/raw/bootstrap/ez_setup.py > python3 ez_setup.py > # download and install pip > curl -O https://raw.github.com/pypa/pip/master/contrib/get-pip.py > python3 get-pip.py > # use pip to install > python3 -m pip install pyserial > # Don't want it? > python3 -m pip uninstall pyserial > > -- > Ned Deily, > [email protected] Ned, Thank you! Belatedly. I’ve had some fires to put out at work. And have gotten back to this, and this is exactly what I was looking for. I added the additional step of: cd /usr/local/bin ln -s ../../../Library/Frameworks/Python.framework/Versions/3.3/bin/pip pip Works, like a charm. (aside. I do not use GoogleGroups, but have been accused of somehow sending email that looks like I do. Does this email look like that?) -- https://mail.python.org/mailman/listinfo/python-list
Re: How to install pip for python3 on OS X?
On Friday 2013 November 22 12:10, Travis Griggs wrote: > (aside. I do not use GoogleGroups, but have been accused of somehow sending > email that looks like I do. Does this email look like that?) No. -- Yonder nor sorghum stenches shut ladle gulls stopper torque wet strainers. -- https://mail.python.org/mailman/listinfo/python-list
Re: argparse feature request
On 2013-11-22 18:15, Neal Becker wrote: Robert Kern wrote: On 2013-11-22 16:52, Neal Becker wrote: Robert Kern wrote: On 2013-11-22 14:56, Neal Becker wrote: I use arparse all the time and find it serves my needs well. One thing I'd like to see. In the help message, I'd like to automatically add the default values. What I'd like to see is: --size SIZE [2000] <<< the default value is displayed Use formatter_class=argparse.ArgumentDefaultsHelpFormatter http://docs.python.org/2/library/argparse#argparse.ArgumentDefaultsHelpFormatter Thanks! Almost perfect. Problem is, I don't usually bother to add help='help me' options. It seems that ArgumentDefaultsHelpFormatter doesn't do anything unless help='blah' option is used. Not sure what to do about that. Since python test_freq3.py -h produces useful messages without my adding help=... everywhere, it'd be nice if ArgumentDefaultsHelpFormatter would work here. Patches are welcome, I am sure. Implement a HelpFormatter that does what you want. _format_action() is where the relevant logic is. Try something like this, and modify to suit. class BeckerDefaultFormatter(argparse.ArgumentDefaultsHelpFormatter): def _format_action(self, action): monkeypatched = False if action.default is not None and action.help is None: # Trick the default _format_action() method into writing out # the defaults. action.help = ' ' monkeypatched = True formatted = super(BeckerDefaultFormatter, self)._format_action(action) if monkeypatched: action.help = None return formatted Thanks! Seems to work great. It gave reasonable output for both case where I include help=... and also without. I have no idea how that above code works, but I guess as long as it works... Just take a look at the implementation of HelpFormatter._format_action() and look for where my monkeypatch would change the logic. It took me just a few minutes to figure out how to do it in the first place. There really isn't anything tricky going on. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco -- https://mail.python.org/mailman/listinfo/python-list
Periodic execution with asyncio
Hello guys,
I am using the asyncio package (Codename 'Tulip'), which will be
available in Python 3.4, for the first time.
I want the event loop to run a function periodically (e.g. every 2
seconds). PEP 3156 suggests two ways to implement such a periodic call:
1. Using a callback that reschedules itself, using call_later().
2. Using a coroutine containing a loop and a sleep() call.
I implemented the first approach in a class with an easy to use
interface. It can be subclassed and the run() method
can be overwritten to provide the code that will be called periodically.
The interval is specified in the constructor and the task can be started
and stopped:
import asyncio
class PeriodicTask(object):
def __init__(self, interval):
self._interval = interval
self._loop = asyncio.get_event_loop()
def _run(self):
self.run()
self._handler = self._loop.call_later(self._interval, self._run)
def run(self):
print('Hello World')
def start(self):
self._handler = self._loop.call_later(self._interval, self._run)
def stop(self):
self._handler.cancel()
To run this task and execute run() every 2 seconds you can do:
task = PeriodicTask(2)
task.start()
asyncio.get_event_loop().run_forever()
So far, this works for me. But as I have no experience with asynchronous
IO I have two questions:
1. Is this a reasonable implementation or is there anything to improve?
2. How would you implement the second approach from the PEP (using a
coroutine) with the same interface as my PeriodicTask above?
I tried the second approach but wasn't able to come up with a solution,
as I was too confused by the concepts of coroutines, Tasks, etc.
Regards,
Tobias
--
https://mail.python.org/mailman/listinfo/python-list
Re: Why pickling (was: Traceback when using multiprocessing)
On Sat, Nov 23, 2013 at 3:38 AM, John Ladasky wrote: > On Thursday, November 21, 2013 8:24:05 PM UTC-8, Chris Angelico wrote: > >> Oh, that part's easy. Let's leave the multiprocessing module out of it >> for the moment; imagine you spin up two completely separate instances >> of Python. Create some object in one of them; now, transfer it to the >> other. How are you going to do it? > > For what definition of "completely separate"? > > If I have two instances of the same version of the Python interpreter running > on the same hardware, and the same operating system, I expect I would just > copy a block of memory from one interpreter to the other, and then write some > new pointers. That kind of data sharing has to be the most common kind. > It's also the simplest. Okay, so you copy a block of memory. Now how are you going to guarantee that you picked up everything that object references? Python objects frequently reference other objects: send_me = [1.0, 2.0, 3.0] The block of memory might have the addresses of those three floats, but that'll be invalid in the target. Somehow you need to package up this object and everything else you need. Ultimately, you need some system for turning a single object reference (a pointer, if you like) into the entire package of information needed to recreate that object on the other side. That's what pickling is. It's a compact (with people to fight for its compactness, there's current discussion elsewhere about that) format that can be easily transferred around, which refcounted blocks of memory can't. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
python for everyday tasks
Hello, I'm about held a short course with the title indicated in the subjects. The students are very experienced programmers of our company, with deep knoledge on C, C++, C#, Perl and similar languages, but very limited, or absolutely no knowledge on python. what would you teach to such a group in 5x1.5 hours? I'm looking for the most interesting, unique topics, emphesizing python's strong points. I have already a couple ideas: - a general intro about tuples, lists, dicts, sets, and working with these - functional programming tools, functools, itertools, lambda, map, filter - wsgi, pickle I'd appreciate a lot if you could add some ideas thanks, Mate -- https://mail.python.org/mailman/listinfo/python-list
Re: Periodic execution with asyncio
On 11/22/2013 4:30 PM, Tobias M. wrote:
I am using the asyncio package (Codename 'Tulip'), which will be
available in Python 3.4, for the first time.
Great. New stuff, both behavior and API, needs to be 'exercised',
especially by non-experts in the subject. I have no experience with
async stuff either.
I want the event loop to run a function periodically (e.g. every 2
seconds). PEP 3156 suggests two ways to implement such a periodic call:
The PEP is still the doc, and the Library Manual entry is a stub
pointing back to it.
http://python.org/dev/peps/pep-3156/
1. Using a callback that reschedules itself, using call_later().
2. Using a coroutine containing a loop and a sleep() call.
I implemented the first approach in a class with an easy to use
interface. It can be subclassed and the run() method
can be overwritten to provide the code that will be called periodically.
The interval is specified in the constructor and the task can be started
and stopped:
import asyncio
class PeriodicTask(object):
def __init__(self, interval):
self._interval = interval
self._loop = asyncio.get_event_loop()
def _run(self):
self.run()
self._handler = self._loop.call_later(self._interval, self._run)
def run(self):
print('Hello World')
def start(self):
self._handler = self._loop.call_later(self._interval, self._run)
def stop(self):
self._handler.cancel()
To run this task and execute run() every 2 seconds you can do:
task = PeriodicTask(2)
task.start()
asyncio.get_event_loop().run_forever()
1. Is this a reasonable implementation or is there anything to improve?
It may be both reasonable and subject to change. Here is my version,
with the following changes
* Make the task function a parameter 'func'.
* Rename start to _set to better describe what is does and call it in
the _run function to not repeat the handler setting line. (If 'start'
has any magic meaning, I am not aware of it. I am aware that there could
be situations in which one would want a public method, to be called from
other handlers. But that would be a different class ;-)
* Fully initialize the instance in __init__ by calling _set.
* Provide a clean way to stop the event loop without a traceback (or
using Windows Task Manager.
* Comment out the stop method because it is useless in the current
usage. I believe handler.cancel is only relevant after the handler is
set and before it is fired. This can only be done from another handler.
import asyncio
class PeriodicTask(object):
def __init__(self, func, interval):
self.func = func
self.interval = interval
self._loop = asyncio.get_event_loop()
self._set()
def _set(self):
self._handler = self._loop.call_later(self.interval, self._run)
def _run(self):
self.func()
self._set()
## def stop(self):
## self._handler.cancel()
def f():
print('Hello World')
task = PeriodicTask(f, 2)
try:
asyncio.get_event_loop().run_forever()
except KeyboardInterrupt:
print('Loop stopped')
2. How would you implement the second approach from the PEP (using a
coroutine) with the same interface as my PeriodicTask above?
Theoretically, by Guido's rationale, that should be easier (for me, at
least), since it would be more like the kind of Python code I already write.
I tried the second approach but wasn't able to come up with a solution,
as I was too confused by the concepts of coroutines, Tasks, etc.
I will try to look at the PEP and see how it works for me.
--
Terry Jan Reedy
--
https://mail.python.org/mailman/listinfo/python-list
find matching contiguous text
Hi. I have a xpath test that generates the text/html between two xpath functions, basically a chunk of HTML between two dom elements. However, it's slow. As a test, I'd like to compare the speed if I get all the HTML following a given element, and then get all the HTML preceding a given element.. and then do a "union/join/intersection" of the text between the two text segments. I'm trying to find an efficient/effective approach to determining the contiguous matching text, where the text starts with the 1st line in the test from the following element test. Thanks -- https://mail.python.org/mailman/listinfo/python-list
Re: Recursive generator for combinations of a multiset?
On Thu, 21 Nov 2013 12:59:26 -0800 Dan Stromberg wrote: > On Wed, Nov 20, 2013 at 10:46 PM, John O'Hagan > wrote: > > > > > Short story: the subject says it all, so if you have an answer > > already, fire away. Below is the long story of what I'm using it > > for, and why I think it needs to be recursive. It may even be of > > more general interest in terms of filtering the results of > > generators. > > > > I think you probably need permutations rather than combinations. > > Also, I think you'll need to form a word (partitioned off by spaces), > and then check it against a set containing /usr/share/dict/words > before recursing for the remainder of the sentence - this should > speed things up a LOT. Thanks for the reply. If I understand you correctly, you are suggesting permuting the input _characters_ to form words and then seeing if they exist, as opposed to my approach of combining known words and seeing if they are anagrams. (Permutations of words would not help find anagrams as they merely change the word order). Here is an attempt at that: def anagrams(partition, input_string): """Find anagrams which fit given partition of input string length""" if not partition: yield (), input_string return for words, checkstring in anagrams(partition[:-1], input_string): for word in itertools.permutations(checkstring, partition[-1]): word = ''.join(word) if word in WORDS: #WORDS is collection of dictionary words newstring = checkstring for l in word: newstring = newstring.replace(l, '' , 1) yield words + (word,), newstring There are two problems with this. If there are repeated characters in the input, redundant results are produced; a multiset-permutation algorithm would fix this. But the main problem is it is incredibly slow: on my run-of-the-mill laptop, it chokes on anything longer than about 10 characters, spending most of its time rejecting non-words. Or have I misunderstood your suggestion? Regards, -- John -- https://mail.python.org/mailman/listinfo/python-list
Re: Recursive generator for combinations of a multiset?
On Thu, 21 Nov 2013 18:14:41 -0800 (PST)
James wrote:
> On Thursday, November 21, 2013 5:01:15 AM UTC-8, John O'Hagan wrote:
[...]
> > > On 21 November 2013 06:46, John O'Hagan
> >
> > > wrote:
> >
[...]
> >
> > > > def multicombs(it, r):
> >
> > > > result = it[:r]
> >
> > > > yield result
> >
> > > > while 1:
> >
> > > > for i in range(-1, -r - 1, -1):
> >
> > > > rep = result[i]
> >
> > > > if rep < it[i]:
> >
> > > > break
> >
> > > > else:
> >
> > > > break
> >
> > > > for j, n in enumerate(it):
> >
> > > > if n > rep:
> >
> > > > break
> >
> > > > result = result[:i] + it[j:j - i]
> >
> > > > yield result
> >
> > >
[...]
> >
> > I neglected to mention that multicombs takes a sorted iterable;
> >
> > it doesn't work right otherwise. I'd forgotten that because my
> >
> > wordlists are guaranteed sorted by the way they're built. Sorry
> > about
> >
> > that.
> >
> >
> >
> > In my use-case the first argument to multicombs is a tuple of words
> >
> > which may contain duplicates, and it produces all unique
> > combinations
> >
> > of a certain length of those words, eg:
> >
> >
> >
> > list(multicombs(('cat', 'hat', 'in', 'the', 'the'), 3))
> >
> >
> >
> > [('cat', 'hat', 'in'), ('cat', 'hat', 'the'), ('cat', 'in', 'the'),
> >
> > ('cat', 'the', 'the'), ('hat', 'in', 'the'), ('hat', 'the', 'the'),
> >
> > ('in', 'the', 'the')]
> >
> >
[...]
> > What I'm looking for is a recursive algorithm which does what
> >
> > multicombs does (order unimportant) so that I can apply a pruning
> >
> > shortcut like the one I used in the recursive cartesian product
> >
> > algorithm in my original post.
> >
> >
> >
> > Multiset combination algorithms seem pretty thin on the ground out
> >
> > there - as I said, I could only find a description of the procedure
> >
> > above, no actual code. The ones I did find are non-recursive. I'm
> >
> > hoping some combinatorics and/or recursion experts can offer
> > advice.
> >
> >
[...]
> >
> > John
>
> Could convert the following perl script to python?
>
> use Data::Dump qw(dump);
> dump combo([@ARGV], 3);
>
> sub combo {
> my ($t, $k) = @_;
> my @T = @$t;
> my @R = ();
> my %g = ();
> if ($k == 1) {
> for (@T) {
> push @R, $_ unless $g{$_}++;
> }
> } else {
> while (my $x = shift @T) {
> $p = combo([@T], $k-1);
> for (@{$p}) {
> my $q = $x.",".$_;
> push @R, $q unless $g{$q}++;
> }
> }
> }
> [@R];
> }
>
> $ prog.pl cat hat in the the
> [
> "cat,hat,in",
> "cat,hat,the",
> "cat,in,the",
> "cat,the,the",
> "hat,in,the",
> "hat,the,the",
> "in,the,the",
> ]
>
> James
Thanks. Now I just have to learn Perl to understand what that
does! :)
Regards,
--
John
--
https://mail.python.org/mailman/listinfo/python-list
Re: Periodic execution with asyncio
On 11/22/2013 7:00 PM, Terry Reedy wrote:
On 11/22/2013 4:30 PM, Tobias M. wrote:
[snip callback versions by Tobias and me]
2. How would you implement the second approach from the PEP (using a
coroutine) with the same interface as my PeriodicTask above?
Theoretically, by Guido's rationale, that should be easier (for me, at
least), since it would be more like the kind of Python code I already
write.
I tried the second approach but wasn't able to come up with a solution,
as I was too confused by the concepts of coroutines, Tasks, etc.
I will try to look at the PEP and see how it works for me.
I was initially baffled also until I managed to assemble all the needed
pieces.
import asyncio
def f():
print('Hello World')
@asyncio.coroutine
def g(func, interval):
while True:
yield from asyncio.sleep(interval)
func()
loop = asyncio.get_event_loop()
try:
loop.run_until_complete(asyncio.Task(g(f, 2)))
except KeyboardInterrupt:
print('Loop stopped')
I think Guido's point is that async generator version is quite similar
to the 'normal' synchronous version.
import time
def f():
print('Hello World')
def h(func, interval):
while True:
time.sleep(interval)
func()
try:
h(f, 2))
except KeyboardInterrupt:
print('Loop stopped')
--
Terry Jan Reedy
--
https://mail.python.org/mailman/listinfo/python-list
Re: Suggest an open-source issue tracker, with github integration and kanban boards?
Miki: I would much prefer a Python implementation. On Thu, Nov 21, 2013 at 4:07 AM, Miki Tebeka wrote: > On Wednesday, November 20, 2013 6:36:56 AM UTC-8, Alec Taylor wrote: >> Anyway, here is the link: https://github.com/rauhryan/huboard > I thought you wanted a Python bases solution. > -- > https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
select.select()
please help me.. what does the following line do? read_sockets,write_sockets,error_sockets = select.select(CONNECTION_LIST,[],[]) -- https://mail.python.org/mailman/listinfo/python-list
Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
On Fri, 22 Nov 2013 18:22:29 +0530, Bharath Kummar wrote: > Could you please help me with my current research ? Am implementing the > concept in python language. > My doubts are : > 1) Is it possible to Retrieve the address of a variable in python ? > 2) Is it possible to Delete the Address of the Variable and create a > new dynamic address inside the compiler/interpreter itself ? > 3) Is it easy to find the Binary equivalence of a given Alphanumeric > String ? > 4) Is it possible to count the number of 1's in the Binary equivalence > ? > Could you PLEASE provide me with the codes (codes only for the asked > queries) ? The codes are: 1) 7373a28109a7c4473a475b2137aa92d5 2) f2fae9a4ad5ded75e4d8ac34b90d5c9c 3) 935544894ca6ad7239e0df048b9ec3e5 4) b1bc9942d029a4a67e4b368a1ff8d883 Please contact your local government eavesdropping agency for assistance on decoding the codes. -- Denis McMahon, [email protected] -- https://mail.python.org/mailman/listinfo/python-list
Re: python for everyday tasks
On Fri, 22 Nov 2013 15:59:19 -0800, koch.mate wrote:
> Hello,
>
> I'm about held a short course with the title indicated in the subjects.
> The students are very experienced programmers of our company, with deep
> knoledge on C, C++, C#, Perl and similar languages, but very limited, or
> absolutely no knowledge on python.
>
> what would you teach to such a group in 5x1.5 hours? I'm looking for the
> most interesting, unique topics, emphesizing python's strong points.
>
> I have already a couple ideas:
> - a general intro about tuples, lists, dicts, sets, and working with
> these - functional programming tools, functools, itertools, lambda,
> map, filter - wsgi, pickle
Do you have any system administrators in the audience? If so, I'd show
the IPython shell, which includes a lot of custom "magic" to make it a
powerful shell as easy to use as bash. For example, compare the regular
Python REPL:
py> import os, glob
py> glob.glob(os.path.expanduser('~/lam*'))
['/home/steve/lambert.ods', '/home/steve/lambert.csv', '/home/steve/
lambertw.pdf', '/home/steve/lambert-v2.pdf', '/home/steve/lambert.txt']
with the IPython shell:
In [1]: ls ~/lam*
/home/steve/lambert.csv /home/steve/lambert.txt /home/steve/
lambertw.pdf
/home/steve/lambert.ods /home/steve/lambert-v2.pdf
You'll probably want to discuss the similarities and differences between
Python and other languages. In my experience, the most confusing part of
learning a new language is the things which are *almost* but not quite
the same, rather than those which are radically different. When things
are obviously different, you come in to it with no preconceived ideas.
* Python uses name binding, not variables at fixed locations;
* therefore there are no pointers (except under the hood, in the
implementation);
* but you won't miss them. Honest.
* Python uses "call by object sharing", which is exactly the same calling
convention that the Java people call "call by value" and Ruby people call
"call by reference". Here's an opinionated post I wrote some years ago
describing the differences:
https://mail.python.org/pipermail/tutor/2010-December/080505.html
* Python is not Java, and Java is not Python either:
http://dirtsimple.org/2004/12/python-is-not-java.html
http://dirtsimple.org/2004/12/java-is-not-python-either.html
* Everything in Python is an object. *Everything*. There is no
distinction between boxed and unboxed integers, for example, they're all
boxed.
* When I say everything, I mean it. Functions and methods are objects
too. So are classes, and yes, that means that you can inspect the class
of a class (the metaclass).
* Need high performance numeric computing? Python tools like numpy,
pandas, nltk and others are rapidly becoming *the* standard tool for
numeric and scientific computing:
http://blog.mikiobraun.de/2013/11/how-python-became-the-language-of-
choice-for-data-science.html
http://www.talyarkoni.org/blog/2013/11/18/the-homogenization-of-
scientific-computing-or-why-python-is-steadily-eating-other-languages-
lunch/
* Some terminology differences:
- What some languages call members, or class variables and
instance variables, Python usually calls class or instance
attributes. (Although the documentation is a tad inconsistent
in this.) This makes sense: if a string variable is a
variable holding a string, and an int variable is a variable
holding an int, then surely a class variable is a variable
holding a class. (Remember what I said about classes being
objects too?)
- Python class methods are what Java calls static methods, and
Python static methods are kind of like functions only not.
(You'll probably never find a good use for static methods in
Python.)
- There are no procedures or void functions in Python, but
there are functions which return None, which is as close as
you'll get to nil or null.
- I already mentioned the pass by object sharing thing.
* The Zen of Python: at the interactive interpreter, type "import this".
It's not quite a joke and not quite serious, but a little of both, and it
gives a good insight into what the Python core developers consider best
practice.
* Note to Perl coders: you'll notice that "Only One Way To Do It" is NOT
in there, and it never has been.
* Docstrings and doctest.
* Unittest is great for test-driven development.
* Python 3 (although not Python 2) is one of the few languages that get
Unicode *right*. Strings in Python 3 are text, sequences of Unicode
characters, not a thinly disguised blob of bytes. Starting with Python
3.3, Python does away with the difference between "narrow builds" (which
save memory at the expense of correctness) and "wide builds" (which give
correct Unicode behaviour at the cost of memory). Instead, Python 3.3 now
has optimized strings that use only as much memory as needed. Pure ASCII
strings will use 1 byte per character, while Unicode strings use 1, 2 or
4
Re: Newbie - Trying to Help a Friend
On Wed, 20 Nov 2013 11:38:14 +, Duncan Booth wrote: > Denis McMahon wrote: >> 1) Find all the numbers less than n that are not divisible by a, b, or >> c. >> ask the user for x; >> assign the value 0 to some other variable i; >> while i is not greater than than x do the following [ >> if i is not divisible by a and i is not divisible by b and i is not >> divisible by c then display i to the user; >> add 1 to i; >> ] > The question didn't ask to find all the numbers, it asked to count how > many there are. My post was intended as a demonstration of how you can convert a problem into a sequence of steps that can then be programmed into a computer. Any resemblance to the posted question may have been accidental. -- Denis McMahon, [email protected] -- https://mail.python.org/mailman/listinfo/python-list
Re: select.select()
In article ,
Bhanu Karthik wrote:
> please help me.. what does the following line do?
>
> read_sockets,write_sockets,error_sockets =
> select.select(CONNECTION_LIST,[],[])
This is a little tricky.
First,read the docs at http://docs.python.org/2/library/select.html.
There's a lot of complicated stuff there, but just concentrate on the
description of the select.select() call for now.
Imagine a process which has a lot of network connections open. A great
example would be something like a MUD (Multi User Dungeon). You've got
one server process(*) and a bunch of clients which have all made TCP
connections over individual sockets.
Each client will be sending commands asynchronously, and the server
needs to handle this. You need some way to figure out which of those
sockets have something that's been sent to you (which you need to
process) and which are just sitting idle. That's where select() comes
in. It gives you a way to say, "Here's a list of sockets. Sleep until
one of them has something available for me to read, and let me know
which one."
One bit of complication is that you can also check for sockets which are
ready to be written on, and sockets which have some sort of error
condition. That's why the call returns a 3-tuple. But, for now, let's
just concentrate on reading.
Here's a very simplistic server which uses select():
import socket
import select
sock = socket.socket()
sock.bind(('localhost', 23000))
sock.listen(10)
# Accept four connections.
connections = []
for i in range(4):
s, addr = sock.accept()
print "Got connection from %s" % str(addr)
connections.append(s)
while True:
readable, _, _ = select.select(connections, [], [])
print "ready for reading: %s" % readable
for s in readable:
data = s.recv(1024)
print "Read from %s: %s" % (s, data)
You can write a little client which connects to this (I've got one I
used for testing, but I'll leave it to you to write one yourself as an
exercise). Connect four clients, and have them send some input in
random order.
Actually, this server has a bug (which you'll discover as soon as you
close one of the four connection), but it should serve to illustrate the
basic concept.
(*) I'm not sure if real MUDs are programmed this way, but it's a
plausible architecture. For simplicity sake, I'm assuming a
single-threaded server.
--
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Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
On Sat, 23 Nov 2013 01:55:44 +, Denis McMahon wrote: > On Fri, 22 Nov 2013 18:22:29 +0530, Bharath Kummar wrote: >> Could you PLEASE provide me with the codes (codes only for the asked >> queries) ? > > The codes are: > > 1) 7373a28109a7c4473a475b2137aa92d5 > 2) f2fae9a4ad5ded75e4d8ac34b90d5c9c > 3) 935544894ca6ad7239e0df048b9ec3e5 > 4) b1bc9942d029a4a67e4b368a1ff8d883 > > Please contact your local government eavesdropping agency for assistance > on decoding the codes. I'm not an expert on Indian English, but I understand that in that dialect it is grammatically correct to say "the codes", just as in UK and US English it is grammatically correct to say "the programs". In other words, in UK/US English, "code" in the sense of programming code is an uncountable noun, like "rice" or "air", while in Indian English it is a countable noun like cats or programs. We have to say "give me two samples of code", or perhaps "two code samples", while an Indian speaker might say "give me two codes". As this is an international forum, it behoves us all to make allowances for slight difference in dialect. Aside: I love the fact that pea, as in green peas or black-eyed peas, is a back-formation from an uncountable noun. Originally English had the word "pease", as in "pease porridge hot" from the nursery rhyme. Like wheat, rice, barley and others, You would have to say something like "give me a grain of pease" if you only wanted one. Eventually, people began to assume that "pease", or "peas", was the plural and therefore "pea" must be the singular. I look forward to the day that "rice" is the plural of "ri" :-) -- Steven -- https://mail.python.org/mailman/listinfo/python-list
Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
Try posting in text, as some of us see nothing in your message. This is a text newsgroup, not html. Also make a subject line that summarizes your issue, not the urgency. -- DaveA -- https://mail.python.org/mailman/listinfo/python-list
Re: select.select()
On Fri, 22 Nov 2013 17:42:07 -0800, Bhanu Karthik wrote: > please help me.. what does the following line do? > > read_sockets,write_sockets,error_sockets = > select.select(CONNECTION_LIST,[],[]) The select.select function takes three arguments (plus an optional fourth): select.select(read_list, write_list, exception_list) Each list should a list of the file descriptors you want to wait for. On Windows, only sockets are valid file descriptors. On Unix or Linux, you can use sockets, open file objects, or low-level file descriptors. In this case, you only pass CONNECTION_LIST, the others are empty lists []. CONNECTION_LIST is probably a list of sockets to be read. When they are ready for reading, select() will return three lists: read_sockets - a list of the sockets open for reading write_sockets and error_sockets should both be empty lists, since you didn't request any of those to be opened. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
Re: python for everyday tasks
On Friday, November 22, 2013 6:59:19 PM UTC-5, [email protected] wrote: > Hello, > > I'm about held a short course with the title indicated in the subjects. The > students are very experienced programmers of our company, with deep knoledge > on C, C++, C#, Perl and similar languages, but very limited, or absolutely no > knowledge on python. > > what would you teach to such a group in 5x1.5 hours? I'm looking for the most > interesting, unique topics, emphesizing python's strong points. > > I have already a couple ideas: > - a general intro about tuples, lists, dicts, sets, and working with these > - functional programming tools, functools, itertools, lambda, map, filter > - wsgi, pickle > > I'd appreciate a lot if you could add some ideas > > thanks, > Mate I gave a 45-minute presentation at the DevDays conference in 2009 to introduce programmers to Python. The slides are here: http://nedbatchelder.com/text/devdays.html Sorry there's no text to go with them. They introduce the good points of Python, then go through two code exercises: Peter Norvig's spellchecker, which is great for showing off data structures; and a micro templating engine, which takes advantage of Python's dynamic nature. --Ned. -- https://mail.python.org/mailman/listinfo/python-list
Re: Recursive generator for combinations of a multiset?
On 23/11/2013 00:58, John O'Hagan wrote: On Thu, 21 Nov 2013 12:59:26 -0800 Dan Stromberg wrote: On Wed, Nov 20, 2013 at 10:46 PM, John O'Hagan wrote: > > Short story: the subject says it all, so if you have an answer > already, fire away. Below is the long story of what I'm using it > for, and why I think it needs to be recursive. It may even be of > more general interest in terms of filtering the results of > generators. > I think you probably need permutations rather than combinations. Also, I think you'll need to form a word (partitioned off by spaces), and then check it against a set containing /usr/share/dict/words before recursing for the remainder of the sentence - this should speed things up a LOT. Thanks for the reply. If I understand you correctly, you are suggesting permuting the input _characters_ to form words and then seeing if they exist, as opposed to my approach of combining known words and seeing if they are anagrams. (Permutations of words would not help find anagrams as they merely change the word order). Here is an attempt at that: def anagrams(partition, input_string): """Find anagrams which fit given partition of input string length""" if not partition: yield (), input_string return for words, checkstring in anagrams(partition[:-1], input_string): for word in itertools.permutations(checkstring, partition[-1]): word = ''.join(word) if word in WORDS: #WORDS is collection of dictionary words newstring = checkstring for l in word: newstring = newstring.replace(l, '' , 1) yield words + (word,), newstring There are two problems with this. If there are repeated characters in the input, redundant results are produced; a multiset-permutation algorithm would fix this. But the main problem is it is incredibly slow: on my run-of-the-mill laptop, it chokes on anything longer than about 10 characters, spending most of its time rejecting non-words. Or have I misunderstood your suggestion? If you want to know how to get unique permutations, have a look here: http://mail.python.org/pipermail/python-ideas/2013-October/023610.html -- https://mail.python.org/mailman/listinfo/python-list
Re: select.select()
On Friday, 22 November 2013 18:29:12 UTC-8, Steven D'Aprano wrote: > On Fri, 22 Nov 2013 17:42:07 -0800, Bhanu Karthik wrote: > > > > > please help me.. what does the following line do? > > > > > > read_sockets,write_sockets,error_sockets = > > > select.select(CONNECTION_LIST,[],[]) > > > > The select.select function takes three arguments (plus an optional > > fourth): > > > > select.select(read_list, write_list, exception_list) > > > > Each list should a list of the file descriptors you want to wait for. On > > Windows, only sockets are valid file descriptors. On Unix or Linux, you > > can use sockets, open file objects, or low-level file descriptors. > > > > In this case, you only pass CONNECTION_LIST, the others are empty lists > > []. CONNECTION_LIST is probably a list of sockets to be read. When they > > are ready for reading, select() will return three lists: > > > > read_sockets - a list of the sockets open for reading > > > > write_sockets and error_sockets should both be empty lists, since you > > didn't request any of those to be opened. > > > > > > > > -- > > Steven Thank you ,your message answered the question exactly. instead of using select.select,can we do like below? read_sockets=connection_list write_sockets=[] error_sockets=[] -- https://mail.python.org/mailman/listinfo/python-list
Re: select.select()
On Friday, 22 November 2013 18:15:10 UTC-8, Roy Smith wrote:
> In article ,
>
> Bhanu Karthik wrote:
>
>
>
> > please help me.. what does the following line do?
>
> >
>
> > read_sockets,write_sockets,error_sockets =
>
> > select.select(CONNECTION_LIST,[],[])
>
>
>
> This is a little tricky.
>
>
>
> First,read the docs at http://docs.python.org/2/library/select.html.
>
> There's a lot of complicated stuff there, but just concentrate on the
>
> description of the select.select() call for now.
>
>
>
> Imagine a process which has a lot of network connections open. A great
>
> example would be something like a MUD (Multi User Dungeon). You've got
>
> one server process(*) and a bunch of clients which have all made TCP
>
> connections over individual sockets.
>
>
>
> Each client will be sending commands asynchronously, and the server
>
> needs to handle this. You need some way to figure out which of those
>
> sockets have something that's been sent to you (which you need to
>
> process) and which are just sitting idle. That's where select() comes
>
> in. It gives you a way to say, "Here's a list of sockets. Sleep until
>
> one of them has something available for me to read, and let me know
>
> which one."
>
>
>
> One bit of complication is that you can also check for sockets which are
>
> ready to be written on, and sockets which have some sort of error
>
> condition. That's why the call returns a 3-tuple. But, for now, let's
>
> just concentrate on reading.
>
>
>
> Here's a very simplistic server which uses select():
>
>
>
> import socket
>
> import select
>
>
>
> sock = socket.socket()
>
> sock.bind(('localhost', 23000))
>
> sock.listen(10)
>
>
>
> # Accept four connections.
>
> connections = []
>
> for i in range(4):
>
> s, addr = sock.accept()
>
> print "Got connection from %s" % str(addr)
>
> connections.append(s)
>
>
>
> while True:
>
> readable, _, _ = select.select(connections, [], [])
>
> print "ready for reading: %s" % readable
>
> for s in readable:
>
> data = s.recv(1024)
>
> print "Read from %s: %s" % (s, data)
>
>
>
> You can write a little client which connects to this (I've got one I
>
> used for testing, but I'll leave it to you to write one yourself as an
>
> exercise). Connect four clients, and have them send some input in
>
> random order.
>
>
>
> Actually, this server has a bug (which you'll discover as soon as you
>
> close one of the four connection), but it should serve to illustrate the
>
> basic concept.
>
>
>
>
>
> (*) I'm not sure if real MUDs are programmed this way, but it's a
>
> plausible architecture. For simplicity sake, I'm assuming a
>
> single-threaded server.
Thank you for your reply.your reply helped me figure out concept.
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JSON translated into SQL by python
I am new to programming python for JSON to SQL and I was wondering why this
does not work. All the values for entering the DB are correct. The
EnterpriseValue data is not entering the database.
#collect data from JSON source at Yahoo
url = ["db", "http://y.ahoo.it/wlB89";]
#check all sites
checkstatus(url[]);
#retrieve EnterpriseValue data from yahoo to DB
url = "http://y.ahoo.it/wlB89";
data = helper.openJSON_URL(url)
#store data
curObservation = data["EnterpriseValue"]
#connect to amazon and post data from Yahoo
conn = inti_psql_amazon("db name", "db user", "password", "db source")
query = "CREATE TABLE temp2 (ID int NOT NULL AUTO_INCREMENT, Enterprise_Value
float, PRIMARY KEY(ID));"
query = "INSERT INTO TABLE temp2 (enterprise) VALUES("+ str(curObservation)
+");"
do_query_amazon(conn, query)
close_psql_amazon(conn)
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Re: python for everyday tasks
Teach that Python emphasizes readability. Perhaps talk about bugs / lines_of_code being roughly a constant. Then talk about the fact that Python generally takes fewer lines of code to express the same thing. This implies fewer bugs for many projects. Teach the fundamental types, with differences from other languages: int, float (C double), decimal, maybe fractions. Booleans. lists, arrays, dictionaries, sets, tuples, frozensets. Teach that variables don't have a type, but values do. Teach a = b. Teach a, b = b, a. Teach that python is duck typed (dynamically typed), and isn't manifestly or statically typed. Provide definitions. Discuss what it means to be "strongly typed", which doesn't mean what a lot of people think it does: Python is strongly typed, the main exception being that you can use almost anything in a boolean context. Teach the control flow, with differences from other languages: while, for/else, if/elif/else. break/continue, list comprehensions, and maybe generator expressions. Include things like enumerate() and iterators and with statements. Probably do yield too - it's not crucial to being productive in python, but it's plenty useful; probably show how it can generate powers of 2 forever or something. Teach that python has builtins, not keywords - IOW, you can redefine list or int, but you probably shouldn't. pylint helps with this. Teach classes with __init__. Teach __str__, __repr__, and teach __cmp__ or __lt__ (depending on your python version), and perhaps some other magic methods like (a subset of) emulating a container, or emulating a number. Maybe talk about Python's stellar built in Timsort that was later adopted by Java. Teach pylint, including how to turn off unimportant warnings; I usually do this in my code, but you can also use a pylintrc. A short time talking about pylint (or pychecker or pyflakes, and perhaps pep8 too) should help them teach themselves quite a bit - think of these as expert systems about how to write better python. Personally, I use a pyflakes plugin in vim, but my default "make" rule invokes pylint for "the" entire project, as well as my automated tests one at a time. Sometimes my default "make" rule does pep8 too, but not always; pylint covers a lot of what pep8 does anyway. Touch briefly on a cross-platform debugger like winpdb (it's cross-platform despite the name) or pudb. Some people will prefer to just do print functions/statements (again depending on python version), but others will really value the debugger, and some people will use some of both. Stress the importance of automated tests relative to other languages. IMO, even with pylint, having plenty of good automated tests is crucial in a large python project, especially if it's multi-programmer. If you have time, provide some guidance about whether to use Python 2.x or 3.x. IMO, projects that have their dependencies satisfied in 3.x (or have no dependencies!), should use 3.x today. Otherwise, use 2.x with "from __future__" imports where practical. Talk about decorators. If you have time, maybe talk about available interpreters: CPython 2.x, CPython 3.x, Jython (python in java that can call java classes), Pypy (python in python with a JIT), IronPython (IronPython lacks a standard library for the most part, but lets you talk to .net classes). Maybe also talk about Python in the browser: http://stromberg.dnsalias.org/~strombrg/pybrowser/python-browser.html . There was a time when Jython could be used for in-browser-python by generating .class files, but I don't think it can anymore, and java browser plugins seem to be disappearing anyway; the world seems to be heading toward javascript for in-browser, RIA. Feel free to raid http://stromberg.dnsalias.org/~dstromberg/Intro-to-Python/for slides. HTH On Fri, Nov 22, 2013 at 3:59 PM, wrote: > Hello, > > I'm about held a short course with the title indicated in the subjects. > The students are very experienced programmers of our company, with deep > knoledge on C, C++, C#, Perl and similar languages, but very limited, or > absolutely no knowledge on python. > > what would you teach to such a group in 5x1.5 hours? I'm looking for the > most interesting, unique topics, emphesizing python's strong points. > > I have already a couple ideas: > - a general intro about tuples, lists, dicts, sets, and working with these > - functional programming tools, functools, itertools, lambda, map, filter > - wsgi, pickle > > I'd appreciate a lot if you could add some ideas > > thanks, > Mate > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Re: Recursive generator for combinations of a multiset?
On Fri, Nov 22, 2013 at 4:58 PM, John O'Hagan wrote: > On Thu, 21 Nov 2013 12:59:26 -0800 > Dan Stromberg wrote: > > > On Wed, Nov 20, 2013 at 10:46 PM, John O'Hagan > > wrote: > > > > > > > > Short story: the subject says it all, so if you have an answer > > > already, fire away. Below is the long story of what I'm using it > > > for, and why I think it needs to be recursive. It may even be of > > > more general interest in terms of filtering the results of > > > generators. > > > > > > > I think you probably need permutations rather than combinations. > > > > Also, I think you'll need to form a word (partitioned off by spaces), > > and then check it against a set containing /usr/share/dict/words > > before recursing for the remainder of the sentence - this should > > speed things up a LOT. > > Thanks for the reply. If I understand you correctly, you are suggesting > permuting the input _characters_ to form words and then seeing if > they exist, as opposed to my approach of combining known words and > seeing if they are anagrams. (Permutations of words would not help find > anagrams as they merely change the word order). Here is an attempt at > that: You've interpreted me correctly. However, I was thinking about this in the back of my mind, and decided it would probably be best to inhale /usr/share/dict/words (if on Linux), and pull out words of the corrects lengths (as separated by the blanks) over the correct (possible) alphabet, and permute Those, afterward checking if they form good anagrams of the original sentence. This would probably be much faster, since English isn't that dense of a space. -- https://mail.python.org/mailman/listinfo/python-list
Re: python for everyday tasks
I almost forgot: Talk about pypi and pip (or similar) too. On Fri, Nov 22, 2013 at 3:59 PM, wrote: > >> Hello, >> >> I'm about held a short course with the title indicated in the subjects. >> The students are very experienced programmers of our company, with deep >> knoledge on C, C++, C#, Perl and similar languages, but very limited, or >> absolutely no knowledge on python. >> >> what would you teach to such a group in 5x1.5 hours? I'm looking for the >> most interesting, unique topics, emphesizing python's strong points. >> >> I have already a couple ideas: >> - a general intro about tuples, lists, dicts, sets, and working with >> these >> - functional programming tools, functools, itertools, lambda, map, filter >> - wsgi, pickle >> >> I'd appreciate a lot if you could add some ideas >> >> thanks, >> Mate >> -- >> https://mail.python.org/mailman/listinfo/python-list >> > > -- https://mail.python.org/mailman/listinfo/python-list
Re: Got a Doubt ! Wanting for your Help ! Plz make it ASAP !
On Fri, Nov 22, 2013 at 7:18 PM, Steven D'Aprano wrote: > I'm not an expert on Indian English, but I understand that in that > dialect it is grammatically correct to say "the codes", just as in UK and > US English it is grammatically correct to say "the programs". I wouldn't necessarily even consider it an Indian thing, as I've known Americans to use the same phrase. On Fri, Nov 22, 2013 at 8:47 PM, Dennis Lee Bieber wrote: > On 23 Nov 2013 02:18:03 GMT, Steven D'Aprano > declaimed the following: > >> >>Aside: I love the fact that pea, as in green peas or black-eyed peas, is >>a back-formation from an uncountable noun. Originally English had the >>word "pease", as in "pease porridge hot" from the nursery rhyme. Like >>wheat, rice, barley and others, You would have to say something like >>"give me a grain of pease" if you only wanted one. Eventually, people >>began to assume that "pease", or "peas", was the plural and therefore >>"pea" must be the singular. I look forward to the day that "rice" is the >>plural of "ri" :-) > > Rice is the plural of rouse Not according to the dictionary. But it does seem a more likely candidate for a hypothetical back formation than "ri", which perhaps was your point. -- https://mail.python.org/mailman/listinfo/python-list
Re: python for everyday tasks
On Sat, Nov 23, 2013 at 5:28 PM, Dan Stromberg wrote: > Teach that python has builtins, not keywords - IOW, you can redefine list or > int, but you probably shouldn't. pylint helps with this. Well, Python has keywords, but uses builtins for many things that other languages use keywords (or magic) for. >>> None=1 SyntaxError: assignment to keyword >>> list=[] >>> del list ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: select.select()
On Sat, Nov 23, 2013 at 1:15 PM, Roy Smith wrote: > (*) I'm not sure if real MUDs are programmed this way, but it's a > plausible architecture. For simplicity sake, I'm assuming a > single-threaded server. Yeah, they certainly can. That's effectively the way that I programmed the MUD kernel that we used at work (not for games, but it's still effectively a MUD), although I used async I/O facilities to abstract away the actual select calls. It's as good as the multi-threaded model (which is what I use in Minstrel Hall - every connection spawns a thread, which does blocking reads and blocking writes; simplifies the code when a command wants to delay the user, as it simply sleep()s), and can often scale to more concurrent connections, although for the bulk of servers that's not going to be an issue. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: JSON translated into SQL by python
On Sat, Nov 23, 2013 at 4:54 PM, Aaron G.
wrote:
> query = "INSERT INTO TABLE temp2 (enterprise) VALUES("+ str(curObservation)
> +");"
You just put the contents of curObservation into the query, as SQL
code. Is that really what you wanted to do? Most likely, you should be
using a parameterized query here; are you familiar with that concept?
You seem to have custom functions to do your database work here.
Without knowing what those functions do, it's hard for us to advise
further.
ChrisA
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