date:20090318

rewonka wrote:

> I had a problem, i would like to process a file into a PSQL, but in
> the file the delimiter char is ':'
> and i have the same charater inside the text field also.
> something like this:
> text = 1:23:34:"sample: text":" something"
> if I use text.split(':')
> it will be ['1', '23', '34', '"sample', 'text"', 'something']
> but it's not good for me, because the delimiter is in text limiter  "
> "
> 
> is it a solution, that is fast to process ? so i don't need to split
> by "hand made" function

Have a look at http://docs.python.org/library/csv.html.

with open(filename, "rb") as instream:
rows = csv.reader(instream, delimiter=":")
# decode, put into db

Peter
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Creating 50K text files in python

Hello all,
  I've an application where I need to create 50K files spread
uniformly across 50 folders in python. The content can be the name of
file itself repeated 10 times.I wrote a code using normal for loops
but it is taking hours together for that. Can some one please share
the code for it using Multithreading. As am new to Python, I know
little about threading concepts.

This is my requiremnt:

C:\TestFolder
That folder contains 5 Folders.. Folder1, Folder2, Folder3.
Folder5
Each folder in turn contains 10 folders:
and Each of those folder contains 1000 text files.

Please let me know if you are not clear.

Thank you,
Venu Madhav.


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Re: REDIRECT

2009-03-18 Thread Jeremiah Dodds

On Wed, Mar 18, 2009 at 10:54 AM,  wrote:

> Hi !
>
> I'm new to Python. I'm having some difficulties to redirect the pages
> using python. Every time when I redirect, the URL changed accordingly.
>
> (Example : from   http://localhost:   to
> http://localhost/hello.py?name='J ')
>
> What's the Python way of implementing this ? Can anyone help me out on
> this ?
>
>
Depends on what framework you're using.

In CherryPy it would be:

raise cherrypy.HTTPRedirect("/hello?name='J'")

What are you using to build your webpage?
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Re: objectoriented -?- functional

Walther Neuper wrote:

> loving Java (oo) 

Don't mind, weirder things have happened 

http://wiki.muenster.org/index.php/Schwan

> as well as SML (fun) I use to practice both of them 
> separately.
> Now, with Python I would like to combine 'oo.extend()' with 'functional
> map':
> 
> Python 2.4.4 (#2, Oct 22 2008, 19:52:44)
> [GCC 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>  >>> def reverse_(list):
> ... """list.reverse() returns None; reverse_ returns the reversed
> list"""
> ... list.reverse()
> ... return list
> ...
>  >>> ll = [[11, 'a'], [33, 'b']]
>  >>> l = ll[:]  # make a copy !
>  >>> l = map(reverse_, l[:])  # make a copy ?
>  >>> ll.extend(l)
>  >>> print("ll=", ll)
> ('ll=', [['a', 11], ['b', 33], ['a', 11], ['b', 33]])
> 
> But I expected to get ...
> ('ll=', [[11, 22], [33, 44], [22, 11], [44, 33]])
> ... how would that elegantly be achieved with Python ?

Sorry, I cannot infer the pattern. How would you do that at all?

Peter
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Re: [python-list] Re: Strange crash issue on Windows w/ PyGTK, Cairo...

2009-03-18 Thread CJ Kucera

[email protected] wrote:
> It looks like some of the C extension you are using is causing a
> segfault or similar in python
> interpreter (or it could be a bug in the interpreter itself, but it is
> a lot less likely).

Okay...  I assume by "C extension" you'd include the PyGTK stuff, right?
(ie: pycairo, pygobject, and pygtk)  Those are the only extras I've got
installed, otherwise it's just a base Python install.

Would a bad extension really cause this kind of behavior though?
Specifically the working-the-first-time and crash-subsqeuent-times?  Do
C extensions contribute to the bytecode generated while compiling?

> I would suggest to fill the startup portion of your code with trace
> statements to try to understand which module function is the
> troublesome one, then go looking in the big tracking system of the
> module, try the newest version and ask on the dedicated mailing list
> if any.

Are you talking about just throwing in various print statements, to find
out where exactly it's dying?  Or I see that there is an actual "trace"
module in Python...  I did do the former awhile ago and didn't find
anything conclusive really.  It was when approaching it from that angle
that I stumbled across the case that if I simply renamed one of my
functions, everything started working again.  I'll do this a bit more
once I've gotten the program down to a more manageable level.

> Making a small script that cabn reproduce the bug is also a very good
> idea, and will help speed-up the problem solution.

Right, that's the goal.  Right now it's still pretty unwieldy, still.
I'll keep on it.

Thanks for the response!

-CJ

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Re: Creating 50K text files in python

[email protected] wrote:

> Hello all,
>   I've an application where I need to create 50K files spread
> uniformly across 50 folders in python. The content can be the name of
> file itself repeated 10 times.I wrote a code using normal for loops
> but it is taking hours together for that. Can some one please share
> the code for it using Multithreading. As am new to Python, I know
> little about threading concepts.
> 
> This is my requiremnt:
> 
> C:\TestFolder
> That folder contains 5 Folders.. Folder1, Folder2, Folder3.
> Folder5
> Each folder in turn contains 10 folders:
> and Each of those folder contains 1000 text files.
> 
> Please let me know if you are not clear.
> 
> Thank you,
> Venu Madhav.

I've just tried it, creating the 50,000 text files took 17 seconds on my not
very fast machine. Python is certainly not the bottleneck here.

Peter
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Re: Creating 50K text files in python

2009-03-18 Thread Tim Chase


  I've an application where I need to create 50K files spread
uniformly across 50 folders in python. The content can be the name of
file itself repeated 10 times.I wrote a code using normal for loops
but it is taking hours together for that. Can some one please share
the code for it using Multithreading. As am new to Python, I know
little about threading concepts.


I'm not sure multi-threading will assist much with what appears 
to be a filesystem & I/O bottleneck.  Far more important will be 
factors like


- what OS are you running?

- what filesystem are you writing to and does it journal?  (NTFS? 
 FAT?  ext[234]?  JFS?  XFS?  tempfs/tmpfs?  etc...)  Some 
filesystems deal much better with lots of small files while 
others perform better with fewer-but-larger files.


- how is that filesystem mounted?  Are syncs forced for all 
writes?  How large are your write caches?


- what sort of hardware is it hitting?  A 4500 RPM drive will 
have far worse performance than a 10k RPM drive; or you could try 
against a flash drive or RAID-0 which should have higher 
sustained write throughput.


- how sparse is the drive layout beforehand?  If you're cramped 
for space, the FS drivers have to scatter your files across 
disparate space; while lots of free-space may allow it to spew 
the files without great consideration.


Hope this gives you some ways to test your configuration...

-tkc





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Re: Creating 50K text files in python

On Mar 18, 6:16 pm, "[email protected]"
 wrote:
> Hello all,
>           I've an application where I need to create 50K files spread
> uniformly across 50 folders in python. The content can be the name of
> file itself repeated 10 times.I wrote a code using normal for loops
> but it is taking hours together for that. Can some one please share
> the code for it using Multithreading. As am new to Python, I know
> little about threading concepts.
>
> This is my requiremnt:
>
> C:\TestFolder
> That folder contains 5 Folders.. Folder1, Folder2, Folder3.
> Folder5
> Each folder in turn contains 10 folders:
> and Each of those folder contains 1000 text files.
>
> Please let me know if you are not clear.
>
> Thank you,
> Venu Madhav.

-
I managed to get this code but the problem is main thread exits before
the completetion of child threads:

class MyThread ( threading.Thread ):

   def run ( self ):

  global theVar
  print 'This is thread ' + str ( theVar ) + ' speaking.'
  print 'Hello and good bye.'
  theVar = theVar + 1
  time.sleep (4)
  print 'This is thread ' + str ( theVar ) + ' speaking. again'

for x in xrange ( 20 ):
   MyThread().start()
---
I can't use a sleep in the main thread because I don't know when the
child threads end.

Thank you,
venu madhav.




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Re: Mangle function name with decorator?

2009-03-18 Thread Adam

On Mar 17, 1:49 pm, Aaron Brady  wrote:

> You would need a unique attribute to look for on values in the
> dictionary, which means you'd need to detect what functions you are
> renaming; possibly by using a decorator to mark them.  (Untested:)
>
> class X( metaclass= M ):
>   @mark( 'A' )
>   def foo( ... ).
>
> class M( type ):
>   def __new__( cls, name, bases, namespace ):
>     for k, v in namespace.items():
>       if v.tag== 'mark-A':
>         namespace[ k ]= modification( v )
> or in your case:
>         del namespace[ k ]
>         namespace[ k_mod ]= v.original
>
> possibly also setting func_name as well.
>     return type( name, bases, namespace )

I tried this, but unfortunately, it still doesn't allow me to have two
methods that initially have the same name, because the namespace
dictionary that the metaclass gets only has one one entry, the last
one in.  So, if I try code like this:

def get_only(action):
setattr(action, "get_only", True)

return action

class ControllerMetaclass(type):
def __new__(cls, name, bases, namespace):
print str(namespace)
for k, v in namespace.items():
if hasattr(v, "get_only"):
new_name = "_get_" + k
print "new_name is " + new_name
del namespace[k]
namespace[new_name] = v
v.__name__ = new_name
return type(name, bases, namespace)

class Controller(object):
def __call__(self):
if (self.method != None):
get_mangled_name = "_" + self.method + "_" + self.action
if hasattr(self, get_mangled_name):
method = getattr(self, get_mangled_name)
return method()
else:
if hasattr(self, self.action):
return getattr(self, self.action)()
else:
raise NotImplementedError
else:
if hasattr(self, self.action):
return getattr(self, self.action)()
else:
raise NotImplementedError

class foo_controller(Controller):
__metaclass__= ControllerMetaclass
def __init__(self, action, method = None):
self.action = action
self.method = method


def foo(self):
print "in foo()"

@get_only
def foo(self):
print "in get_only foo()"

def bar(self):
print "in bar()"


a = foo_controller("foo", "get")
a()

b = foo_controller("foo")
print dir(b)
b()

c = foo_controller("bar","get")
c()

The first definition of foo (the one that is not decorated) is over-
written by the second one, and the metaclass never sees it.  So, I
think that I understand what you said about storing the functions in a
hashtable.  That makes sense, as I can keep a reference to the
function even if ti gets over-written in the class main namespace
dictionary.  However, I'm not entirely sure about how to do that with
decorators.  Wouldn't the decorator function have to be bound to a
context to keep a hastable between calls?  I can't us a bound method
as a decorator, can I?
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Re: Creating 50K text files in python

On Mar 18, 6:35 pm, Peter Otten <[email protected]> wrote:
> [email protected] wrote:
> > Hello all,
> >           I've an application where I need to create 50K files spread
> > uniformly across 50 folders in python. The content can be the name of
> > file itself repeated 10 times.I wrote a code using normal for loops
> > but it is taking hours together for that. Can some one please share
> > the code for it using Multithreading. As am new to Python, I know
> > little about threading concepts.
>
> > This is my requiremnt:
>
> > C:\TestFolder
> > That folder contains 5 Folders.. Folder1, Folder2, Folder3.
> > Folder5
> > Each folder in turn contains 10 folders:
> > and Each of those folder contains 1000 text files.
>
> > Please let me know if you are not clear.
>
> > Thank you,
> > Venu Madhav.
>
> I've just tried it, creating the 50,000 text files took 17 seconds on my not
> very fast machine. Python is certainly not the bottleneck here.
>
> Peter

Really... I just can't beleive it. I am running my scirpt on an
INTEL Core2duo CPU machine with 2GB of RAM. I've started it two hours
back, but still it is running. This is how my code looks like


def createFiles(path):
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Creating files in the
folder "+path+"\n")
global c
global d
os.chdir (path)
k = 1
for k in range (1,1001):
p = "%.2d"%(k)
FName = "TextFile"+c+"_"+d+"_"+p+".txt"
l =1
for l in range(1 , 11):
os.system ("\"echo "+FName+" >> "+FName+"\"")
l = l +1
k = k+1



MainPath = "C:\\Many_5_1KB"
try:
os.mkdir (MainPath)
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Created the base directory
\n")
except:
m.write(strftime("%Y-%m-%d %H:%M:%S") +" base directory already
exists\n")
os.chdir (MainPath)
for i in range (1 , 6):
j = 1
c = "%.2d"%(i)
FolderName ="Folder"+c
try:
os.mkdir (FolderName)
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Created the folder
"+FolderName+"\n")
except:
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Folder "+FolderName+"
already exists \n")
os.chdir (FolderName)
path = os.getcwd ()
#createFiles(path)
for j in range ( 1 , 11):
d = "%.2d"%(j)
FolderName = "Folder"+c+"_"+d
try:
os.mkdir (FolderName)
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Created the
folder "+FolderName+"\n")
except:
m.write(strftime("%Y-%m-%d %H:%M:%S") +" the folder
"+FolderName+" exists \n")
os.chdir (FolderName)
path = os.getcwd ()
createFiles(path)
os.chdir ("..")
j = j + 1
os.chdir ("..")
i = i + 1

Can you please let me know where do I have to modify it, to make it
faster.

Thank you,
Venu Madhav
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Re: Style formating of multiline query, advise

2009-03-18 Thread John Machin

On Mar 18, 11:25 pm, someone  wrote:
> Hi,
>
> what is good :) style for multiline queries to database?
> Is that one ok?
> query = """ SELECT * FROM (
>                    SELECT a.columna, a.columnb, a.iso
>                       FROM all a
>                       WHERE (a.name = LOWER(%s))  ) AS c
>                  JOIN other as b on c.gid = b.id
>                  WHERE class = 'A'
>                  ORDER BY population DESC
>                  LIMIT %s;"""

There's no tablet of stone, like PEP 8 :-) It seems to be a matter of
individual taste; clarity and consistency and not overdoing
parentheses count for me.

IMO you have too much leading whitespace, you have "as" in upper,
lower and no case, and I'd set out the inner select differently:

query = """
SELECT * FROM (
SELECT a.columna, a.columnb, a.iso
FROM all AS a
WHERE a.name = LOWER(%s)
) AS c
JOIN other AS b ON c.gid = b.id
WHERE class = 'A'
ORDER BY population DESC
LIMIT %s;
"""

Cheers,
John
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Re: Creating 50K text files in python

2009-03-18 Thread Marco Mariani


[email protected] wrote:


for k in range (1,1001):

  ...

k = k+1


Man, you have a trouble with loops, all over.
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Re: Python to Perl transalators

2009-03-18 Thread Boris Borcic


Armin wrote:



Why on earth would you want to? That'd be like translating Shakespeare
into a bad rap song!



lol, actually I would prefer a rap song over Shakespeare, so your analogy 
doesn't work there ;)


Why, some people do prefer Perl over Python, so what's wrong with the analogy ?

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Re: Creating 50K text files in python

On Mar 18, 6:58 pm, Marco Mariani  wrote:
> [email protected] wrote:
> >     for k in range (1,1001):
>        ...
> >         k = k+1
>
> Man, you have a trouble with loops, all over.

But the situation demands it.:-(
I've to create 5 folders and 10 folders in each of them. Each folder
again should contain 1000 text files.

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Re: 2to3 does not fix FileType from types Module; no replacement?

2009-03-18 Thread John Roth

On Mar 18, 5:48 am, Benjamin Peterson  wrote:
>   tlink.de> schrieb:
>
> > and I could not find a replacement for 'FileType'.
> > Has this been overlooked?
>
> > Found this thread which does not mention FileType:
> >http://mail.python.org/pipermail/stdlib-sig/2008-April/thread.html#172
>
> > I guess I just did not see something simple.
> > Anyone with a hint?
>
> That's because this isn't simple. Python 3 doesn't have one file type. It has
> several different kinds of streams in the io module. If you're checking for a
> file type, you'll want to use isinstance(some_file, io.IOBase). If you're
> inheriting form it, I suggest you look at the io module's classes.

Nontheless, a warning would be helpful, possibly with some doc.

John Roth
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Re: Creating 50K text files in python

[email protected] wrote:

> On Mar 18, 6:35 pm, Peter Otten <[email protected]> wrote:
>> [email protected] wrote:
>> > Hello all,
>> > I've an application where I need to create 50K files spread
>> > uniformly across 50 folders in python. The content can be the name of
>> > file itself repeated 10 times.I wrote a code using normal for loops
>> > but it is taking hours together for that. Can some one please share
>> > the code for it using Multithreading. As am new to Python, I know
>> > little about threading concepts.
>>
>> > This is my requiremnt:
>>
>> > C:\TestFolder
>> > That folder contains 5 Folders.. Folder1, Folder2, Folder3.
>> > Folder5
>> > Each folder in turn contains 10 folders:
>> > and Each of those folder contains 1000 text files.
>>
>> > Please let me know if you are not clear.
>>
>> > Thank you,
>> > Venu Madhav.
>>
>> I've just tried it, creating the 50,000 text files took 17 seconds on my
>> not very fast machine. Python is certainly not the bottleneck here.
>>
>> Peter
> 
> Really... I just can't beleive it. I am running my scirpt on an
> INTEL Core2duo CPU machine with 2GB of RAM. I've started it two hours
> back, but still it is running. This is how my code looks like
> 
> 
> def createFiles(path):
> m.write(strftime("%Y-%m-%d %H:%M:%S") +" Creating files in the
> folder "+path+"\n")
> global c
> global d
> os.chdir (path)
> k = 1
> for k in range (1,1001):
> p = "%.2d"%(k)
> FName = "TextFile"+c+"_"+d+"_"+p+".txt"
> l =1
> for l in range(1 , 11):
> os.system ("\"echo "+FName+" >> "+FName+"\"")
> l = l +1
> k = k+1
> 
> 
> 
> MainPath = "C:\\Many_5_1KB"
> try:
> os.mkdir (MainPath)
> m.write(strftime("%Y-%m-%d %H:%M:%S") +" Created the base directory
> \n")
> except:
> m.write(strftime("%Y-%m-%d %H:%M:%S") +" base directory already
> exists\n")
> os.chdir (MainPath)
> for i in range (1 , 6):
> j = 1
> c = "%.2d"%(i)
> FolderName ="Folder"+c
> try:
> os.mkdir (FolderName)
> m.write(strftime("%Y-%m-%d %H:%M:%S") +" Created the folder
> "+FolderName+"\n")
> except:
> m.write(strftime("%Y-%m-%d %H:%M:%S") +" Folder "+FolderName+"
> already exists \n")
> os.chdir (FolderName)
> path = os.getcwd ()
> #createFiles(path)
> for j in range ( 1 , 11):
> d = "%.2d"%(j)
> FolderName = "Folder"+c+"_"+d
> try:
> os.mkdir (FolderName)
> m.write(strftime("%Y-%m-%d %H:%M:%S") +" Created the
> folder "+FolderName+"\n")
> except:
> m.write(strftime("%Y-%m-%d %H:%M:%S") +" the folder
> "+FolderName+" exists \n")
> os.chdir (FolderName)
> path = os.getcwd ()
> createFiles(path)
> os.chdir ("..")
> j = j + 1
> os.chdir ("..")
> i = i + 1
> 
> Can you please let me know where do I have to modify it, to make it
> faster.

Multiple (!) os.system() calls to create a file are certainly a bad idea.
Personally I don't use os.chdir() because I try to avoid global state when
possible.

Here's my somewhat carelessly written code. Change the 

root = ...

line as appropriate before you run it (the root folder must not exist).


from __future__ import with_statement

import os

def makedir(*parts):
dir = os.path.join(*parts)
os.mkdir(dir)
return dir

def makefile(*parts):
fn = os.path.join(*parts)
with open(fn, "w") as out:
out.write((parts[-1]+"\n")*10)

if __name__ == "__main__":
root = "./tmp_tree"
makedir(root)
for i in range(1, 6):
outer = "Folder%d" % i
makedir(root, outer)
for k in range(1, 11):
inner = "Folder%02d" % k
dir = makedir(root, outer, inner)
for i in range(1, 1001):
makefile(dir, "file%04d.txt" % i)

Peter
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Re: Creating 50K text files in python

2009-03-18 Thread Gabriel Genellina

En Wed, 18 Mar 2009 11:40:26 -0200, [email protected]  
 escribió:

On Mar 18, 6:16 pm, "[email protected]"
 wrote:



          I've an application where I need to create 50K files spread
uniformly across 50 folders in python. The content can be the name of
file itself repeated 10 times.I wrote a code using normal for loops
but it is taking hours together for that. Can some one please share
the code for it using Multithreading. As am new to Python, I know
little about threading concepts.


I managed to get this code but the problem is main thread exits before
the completetion of child threads:

class MyThread ( threading.Thread ):

   def run ( self ):

  global theVar
  print 'This is thread ' + str ( theVar ) + ' speaking.'
  print 'Hello and good bye.'
  theVar = theVar + 1
  time.sleep (4)
  print 'This is thread ' + str ( theVar ) + ' speaking. again'

for x in xrange ( 20 ):
   MyThread().start()


You have to .join() each thread. Replace the above two lines with:

threads = [MyThread() for x in range(20)]
for thread in threads:
  thread.start()
for thread in threads:
  thread.join()

But this is unrelated to your main problem. You don't have to use threads  
for this.


--
Gabriel Genellina

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Re: Creating 50K text files in python

2009-03-18 Thread Marco Mariani


[email protected] wrote:


for k in range (1,1001):

   ...

k = k+1

Man, you have a trouble with loops, all over.


But the situation demands it.:-(


No. I mean, the for loops are wrong.

Compare with the following and see why


import os

base = '/tmp/foo'

for outer in xrange(1,6):
for inner in xrange(1,11):
d = os.path.join(base, str(outer), str(inner))
os.makedirs(d)
for fnum in xrange(1,1001):
file(os.path.join(d,str(fnum)), 'w').close()

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Re: Creating 50K text files in python

2009-03-18 Thread John Machin

On Mar 19, 12:50 am, "[email protected]"
>         FName = "TextFile"+c+"_"+d+"_"+p+".txt"
>         l =1
>         for l in range(1 , 11):
>             os.system ("\"echo "+FName+" >> "+FName+"\"")
>             l = l +1

That is not the most clear code that I've ever seen. Makeover time!
os.system ("\"echo "+FName+" >> "+FName+"\"")
os.system('"echo ' + FName + ' >> ' + FName + '"')
os.system('"echo %s >> %s"') % (FName, FName)

Some questions:
(1) Isn't that one level of quoting too many?
(2) Does os.system create a whole new shell process to execute that
command?
(3) Can you think of a better/faster way to write 10 lines to a file
than doing os.system in a loop?
(4) Why are you incrementing the loop variable yourself?
(5) Why are you setting the loop variable to 1 before the loop?
(6, 7) as for (4, 5) but this time in relation to the enclosing "for
k..." loop.
(8) Did you actually test that this script was working on some *small*
number of files before you fired it off?
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Re: Creating 50K text files in python

2009-03-18 Thread Gabriel Genellina

En Wed, 18 Mar 2009 11:50:32 -0200, [email protected]  
 escribió:



On Mar 18, 6:35 pm, Peter Otten <[email protected]> wrote:

[email protected] wrote:
> Hello all,
>           I've an application where I need to create 50K files spread
> uniformly across 50 folders in python. The content can be the name of
> file itself repeated 10 times.I wrote a code using normal for loops
> but it is taking hours together for that. Can some one please share
> the code for it using Multithreading. As am new to Python, I know
> little about threading concepts.


I've just tried it, creating the 50,000 text files took 17 seconds on  
my not

very fast machine. Python is certainly not the bottleneck here.


Really... I just can't beleive it. I am running my scirpt on an
INTEL Core2duo CPU machine with 2GB of RAM. I've started it two hours
back, but still it is running. This is how my code looks like


You're creating 50 processes, 50 shells, just to call 'echo' (!)


def createFiles(path):
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Creating files in the
folder "+path+"\n")
global c
global d
os.chdir (path)
k = 1
for k in range (1,1001):
p = "%.2d"%(k)
FName = "TextFile"+c+"_"+d+"_"+p+".txt"
l =1
for l in range(1 , 11):
os.system ("\"echo "+FName+" >> "+FName+"\"")
l = l +1
k = k+1


with open(FName, "w") as f:
  for i in range(10):
f.write(FName)

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Re: objectoriented -?- functional

2009-03-18 Thread Armin

On Wednesday 18 March 2009 10:19:41 Peter Otten wrote:
> Walther Neuper wrote:
> > loving Java (oo)
>
> Don't mind, weirder things have happened
>
> http://wiki.muenster.org/index.php/Schwan
>

LOL!!

> > as well as SML (fun) I use to practice both of them
> > separately.
> > Now, with Python I would like to combine 'oo.extend()' with 'functional
> > map':
> >
> > Python 2.4.4 (#2, Oct 22 2008, 19:52:44)
> > [GCC 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)] on linux2
> > Type "help", "copyright", "credits" or "license" for more information.
> >
> >  >>> def reverse_(list):
> >
> > ... """list.reverse() returns None; reverse_ returns the reversed
> > list"""
> > ... list.reverse()
> > ... return list
> > ...
> >
> >  >>> ll = [[11, 'a'], [33, 'b']]
> >  >>> l = ll[:]  # make a copy !
> >  >>> l = map(reverse_, l[:])  # make a copy ?
> >  >>> ll.extend(l)
> >  >>> print("ll=", ll)
> >
> > ('ll=', [['a', 11], ['b', 33], ['a', 11], ['b', 33]])
> >
> > But I expected to get ...
> > ('ll=', [[11, 22], [33, 44], [22, 11], [44, 33]])
> > ... how would that elegantly be achieved with Python ?
>
> Sorry, I cannot infer the pattern. How would you do that at all?
>
> Peter
> --
> http://mail.python.org/mailman/listinfo/python-list

If you want to reimplement list.extend() (as I understand?) you will have to 
subclass it and change the behaviour.

-- 
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Re: Python to Perl transalators

2009-03-18 Thread Armin

On Wednesday 18 March 2009 11:01:00 Boris Borcic wrote:
> Armin wrote:
> >> 
> >> Why on earth would you want to? That'd be like translating Shakespeare
> >> into a bad rap song!
> >> 
> >
> > lol, actually I would prefer a rap song over Shakespeare, so your analogy
> > doesn't work there ;)
>
> Why, some people do prefer Perl over Python, so what's wrong with the
> analogy ?
>
> --
> http://mail.python.org/mailman/listinfo/python-list

That would mostly apply to people who haven't coded in Python for one reason 
or another.

-- 
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Re: Mangle function name with decorator?

2009-03-18 Thread J. Cliff Dyer

You might be interested in redefining __getattribute__(self, attr) on
your class.  This could operate in conjunction with the hash tables
(dictionaries) mentioned by andrew cooke.  i.e. (untested code):

class C(object):
def __init__(self):
self._get_table = {}
self._post_table = {}

def __getattribute__(self, x):
if self.method=='GET':
return object.__getattribute__(self, _get_table)[x]
elif self.method=='POST':
return object.__getattribute__(self, _post_table)[x]
else:
raise AttributeError
@GET
def foo(x):
return "Got", x
@POST
def foo(x)
return "Posted to", x

This is definitely not functional code, but might get you in the right
direction on __getattribute__.  __getattr__ might also work for you.  I
haven't worked too much with these corners of python.

Cheers,
Cliff

On Tue, 2009-03-17 at 13:54 -0400, andrew cooke wrote:
> ah, ok.  then yes, you can do that with decorators.  you'd need hash
> tables or something similar in a metaclass.  then the decorator would take
> the given function, stick it in the appropriate hash table, and return a
> function that does the dispatch (ie at run time does the lookup from the
> hash table) (you'd only want to set the function once once, so it would
> need to check the function wasn't already defined).  also, the decorator
> would have one name and get/post etc would be an argument.
> 
> this is all documented in the docs and peps, although it's very spread
> around.  you might look at the code for the property decorator - it's not
> doing what you want, but it's an interesting non-trivial example that's
> public.
> 
> http://docs.python.org/library/functions.html#property
> 
> andrew
> 
> 
> Adam wrote:
> > Thanks, Andrew.  I'm trying to accomplish something with a
> > metaprogramming flavor, where, for the convenience of the programmer
> > and the clarity of code, I'd like to have a decorator or some other
> > mechanism do twiddling behind the scenes to make a class do something
> > it wouldn't normally do.
> >
> > Here's a less-obfuscated exmaple:  I want to build a framework for
> > creating MVC web applications in Python (I know, I know, there's
> > already 2^1bazillion of them) where a controller class can have
> > methods that respond to the same action but for different HTTP verbs:
> >
> > class foo_controller(Controller):
> > @GET
> > def new(self):
> > # Display the form to create a new foo
> >
> > @POST
> > def new(self):
> > # Receive a form post with new foo data in it
> >
> > The Controller class will do all of the work behind the scenes to
> > makes sure that the correct method is called at run-time, but for the
> > sake of the programmer, I'd like to supply a clear, friendly syntax
> > like this.  Without a little metaprogramming magic, last-in-wins, and
> > only the second version of foo will end up in the class, so I'd like
> > to mangle the names to something that will result in a unique
> > attribute name and that the Controller class can work with behind the
> > scenes to do the right thing at run time.
> >
> > So, Python experts, am I completely barking up the wrong tree here?
> > --
> > http://mail.python.org/mailman/listinfo/python-list
> >
> >
> 
> 
> --
> http://mail.python.org/mailman/listinfo/python-list
> 

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Re: [python-list] Re: Strange crash issue on Windows w/ PyGTK, Cairo...

2009-03-18 Thread MRAB


CJ Kucera wrote:

[email protected] wrote:

It looks like some of the C extension you are using is causing a
segfault or similar in python
interpreter (or it could be a bug in the interpreter itself, but it is
a lot less likely).


Okay...  I assume by "C extension" you'd include the PyGTK stuff, right?
(ie: pycairo, pygobject, and pygtk)  Those are the only extras I've got
installed, otherwise it's just a base Python install.

Would a bad extension really cause this kind of behavior though?
Specifically the working-the-first-time and crash-subsqeuent-times?  Do
C extensions contribute to the bytecode generated while compiling?


[snip]
One time I was doing some speed tests and I found that the code was
faster the first time it ran, when it had to compile to .pyc. If there
had been caching then it would've been faster after the first time, but
_slower_?

My conclusion was that it was down to memory allocation. If the
interpreter had claimed memory from the OS because it had to compile to
.pyc then more would be immediately available during my timing, hence
higher speed.

So perhaps your problem is that one of the C extensions segfaults unless
more memory is immediately available because the interpreter had to
compile to .pyc.
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ANN: eGenix pyOpenSSL Distribution 0.8.1-0.9.8j now also for Mac OS X

2009-03-18 Thread eGenix Team: M.-A. Lemburg

ANNOUNCING

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Version 0.8.1-0.9.8j

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of the pyOpenSSL Python interface for OpenSSL -
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This announcement is also available on our web-site for online reading:
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INTRODUCTION

The eGenix.com pyOpenSSL Distribution includes everything you need to
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that allows writing SSL aware networking applications as well as
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OpenSSL is an open-source implementation of the SSL protocol
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NEWS

This new release of the eGenix.com pyOpenSSL Distribution fixes a
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by Maxim Sobolev on SourceForge:

http://sourceforge.net/tracker/index.php?func=detail&aid=2543118&group_id=31249&atid=401760

Note that this patch has not yet been integrated into upstream
pyOpenSSL.

We have also fixed several compiler warnings found in the code. The
version of pyOpenSSL you find in the source release has those patches
applied.

Binaries are available for Linux x86 and x64 as well as Windows x86
and Mac OS X PPC/Intel. They include pyOpenSSL and the necessary
OpenSSL libraries.

For Plone users and friends of buildout scripts, we have added
pre-built binaries for Windows. They install just like the Linux
versions and allow easy integration of the archives into buildout
scripts.

DOWNLOADS

The download archives and instructions for installing the package can
be found at:

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UPGRADING

Before installing this version of pyOpenSSL, please make sure that
you uninstall any previously installed pyOpenSSL version. Otherwise,
you could end up not using the included OpenSSL libs.

___

SUPPORT

Commercial support for these packages is available from eGenix.com.
Please see

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for details about our support offerings.

Enjoy,
--
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eGenix.com

Professional Python Services directly from the Source (#1, Mar 18 2009)
>>> Python/Zope Consulting and Support ...http://www.egenix.com/
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Re: Creating 50K text files in python

2009-03-18 Thread S Arrowsmith

[email protected]  wrote:
>FName = "TextFile"+c+"_"+d+"_"+p+".txt"
>l = 1
>for l in range(1 , 11):
>os.system ("\"echo "+FName+" >> "+FName+"\"")
>l = l +1

1. os.system spawns a new process, which on Windows (I'm guessing
you're on Windows given the full path names you've given) is a
particularly expensive operation.

2. You really do have a problem with loops. Not how many your
task has landed you, but the way you're writing them. You
don't need to pre-assign the loop variable, you don't need to
increment it, and it's generally clearer if you use a 0-based
range and add 1 when you use the variable if you need it to be
1-based.

So rewrite the above as:

fname = "TextFile%s_%s_%s.txt" % (c, d, p)
f = open(fname, 'a')
for l in range(10):
f.write(fname)
f.close()

Also:

3. All the logging with m.write is likely to be slowing things
down. It might be useful to see just how much of an impact that's
having.

4. Lose the globals and pass them as function arguments.
-- 
\S

   under construction

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Re: Creating 50K text files in python

2009-03-18 Thread Laurent Rahuel


Hi,

I don't know why you are forking shells using os.system. You should 
either use system commands to do the job or plain python, but mixing 
both should never be an option.


Here is a plain portable python script (using the with statement. Your 
python should not be to old)



from __future__ import with_statement
import os

for i in xrange(1, 1001):
os.mkdir('Folder%s' %i)
for j in xrange(1, 51):
with open('Folder%s%sTextFile%s.txt' %(i, os.sep, j), "w") as f:
f.write('TextFile%s.txt' %j)

Here are the results on a ext3 file system

time python test.py

real0m5.299s
user0m0.939s
sys 0m3.539s

Regards,

Laurent


[email protected] a écrit :

On Mar 18, 6:35 pm, Peter Otten <[email protected]> wrote:

[email protected] wrote:

Hello all,
  I've an application where I need to create 50K files spread
uniformly across 50 folders in python. The content can be the name of
file itself repeated 10 times.I wrote a code using normal for loops
but it is taking hours together for that. Can some one please share
the code for it using Multithreading. As am new to Python, I know
little about threading concepts.
This is my requiremnt:
C:\TestFolder
That folder contains 5 Folders.. Folder1, Folder2, Folder3.
Folder5
Each folder in turn contains 10 folders:
and Each of those folder contains 1000 text files.
Please let me know if you are not clear.
Thank you,
Venu Madhav.

I've just tried it, creating the 50,000 text files took 17 seconds on my not
very fast machine. Python is certainly not the bottleneck here.

Peter


Really... I just can't beleive it. I am running my scirpt on an
INTEL Core2duo CPU machine with 2GB of RAM. I've started it two hours
back, but still it is running. This is how my code looks like


def createFiles(path):
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Creating files in the
folder "+path+"\n")
global c
global d
os.chdir (path)
k = 1
for k in range (1,1001):
p = "%.2d"%(k)
FName = "TextFile"+c+"_"+d+"_"+p+".txt"
l =1
for l in range(1 , 11):
os.system ("\"echo "+FName+" >> "+FName+"\"")
l = l +1
k = k+1



MainPath = "C:\\Many_5_1KB"
try:
os.mkdir (MainPath)
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Created the base directory
\n")
except:
m.write(strftime("%Y-%m-%d %H:%M:%S") +" base directory already
exists\n")
os.chdir (MainPath)
for i in range (1 , 6):
j = 1
c = "%.2d"%(i)
FolderName ="Folder"+c
try:
os.mkdir (FolderName)
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Created the folder
"+FolderName+"\n")
except:
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Folder "+FolderName+"
already exists \n")
os.chdir (FolderName)
path = os.getcwd ()
#createFiles(path)
for j in range ( 1 , 11):
d = "%.2d"%(j)
FolderName = "Folder"+c+"_"+d
try:
os.mkdir (FolderName)
m.write(strftime("%Y-%m-%d %H:%M:%S") +" Created the
folder "+FolderName+"\n")
except:
m.write(strftime("%Y-%m-%d %H:%M:%S") +" the folder
"+FolderName+" exists \n")
os.chdir (FolderName)
path = os.getcwd ()
createFiles(path)
os.chdir ("..")
j = j + 1
os.chdir ("..")
i = i + 1

Can you please let me know where do I have to modify it, to make it
faster.

Thank you,
Venu Madhav

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Re: Style formating of multiline query, advise

2009-03-18 Thread Tino Wildenhain


John Machin wrote:

On Mar 18, 11:25 pm, someone  wrote:

Hi,

what is good :) style for multiline queries to database?
Is that one ok?
query = """ SELECT * FROM (
   SELECT a.columna, a.columnb, a.iso
  FROM all a
  WHERE (a.name = LOWER(%s))  ) AS c
 JOIN other as b on c.gid = b.id
 WHERE class = 'A'
 ORDER BY population DESC
 LIMIT %s;"""


There's no tablet of stone, like PEP 8 :-) It seems to be a matter of
individual taste; clarity and consistency and not overdoing
parentheses count for me.

IMO you have too much leading whitespace, you have "as" in upper,
lower and no case, and I'd set out the inner select differently:

query = """
SELECT * FROM (
SELECT a.columna, a.columnb, a.iso
FROM all AS a
WHERE a.name = LOWER(%s)
) AS c
JOIN other AS b ON c.gid = b.id
WHERE class = 'A'
ORDER BY population DESC
LIMIT %s;
"""


And I'd not recomment SELECT * for anything beside test queries in an
interactive session or if you are going to copy tables...

Regards
Tino


smime.p7s
Description: S/MIME Cryptographic Signature
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Re: How to do this in Python?


Luis Zarrabeitia wrote:

On Tuesday 17 March 2009 06:04:36 pm Jim Garrison wrote:
with open(filename, "rb") as f:
for buf in iter(lambda: f.read(1000),''):
do_something(buff)


This is the most pythonic solution yet.

Thanks to all the responders who took time to ponder this seemingly
trivial question.  I learned a lot about the Python mind-set.
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Re: Mangle function name with decorator?

> class foo_controller(Controller):
> __metaclass__= ControllerMetaclass
> def __init__(self, action, method = None):
> self.action = action
> self.method = method
> 
> 
> def foo(self):
> print "in foo()"
> 
> @get_only
> def foo(self):
> print "in get_only foo()"
> 
> def bar(self):
> print "in bar()"

I don't have any wisdom on the metaclass/decorator stuff, but what
about slightly reformulating the interface?  Instead of having the
programmer type, eg:

@GET
def foo(self): pass

@POST
def foo(self): pass

have them type:

def GET_foo(self): pass
def POST_foo(self): pass

It's even one less character of typing (the  :)

--
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Re: How to do this in Python?

2009-03-18 Thread Mel

Jim Garrison wrote:
> andrew cooke wrote:
>> Jim Garrison wrote:
>>> I'm an experienced C/Java/Perl developer learning Python.
>>> What's the canonical Python way of implementing this pseudocode?
[ ... ]
>> but not doing much binary i/o
>> myself, i suggest:
>> 
>> with open(...) as f:
>>   while (True):
>> buf = f.read(1)
>> if not buf: break
>> ...
[ ... ]

> For a one-off,,your first example would work fine.  See the
> other reply from Tim Chase for a much more Pythonesque
> pattern.  I don't want "for line in f:" because binary
> files don't necessarily have lines and I'm bulk processing
> files potentially 100MB and larger.  Reading them one line
> at a time would be highly inefficient.

It would be more work, but subclassing the file class, with a next method 
yielding the binary record you want would be fairly clean.

Mel.



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Re: Mangle function name with decorator?

2009-03-18 Thread Adam

On Mar 18, 10:33 am, "J. Cliff Dyer"  wrote:
> You might be interested in redefining __getattribute__(self, attr) on
> your class.  This could operate in conjunction with the hash tables
> (dictionaries) mentioned by andrew cooke.  i.e. (untested code):
>
> class C(object):
>     def __init__(self):
>         self._get_table = {}
>         self._post_table = {}
>
>     def __getattribute__(self, x):
>         if self.method=='GET':
>             return object.__getattribute__(self, _get_table)[x]
>         elif self.method=='POST':
>             return object.__getattribute__(self, _post_table)[x]
>         else:
>             raise AttributeError
>     @GET
>     def foo(x):
>         return "Got", x
>     @POST
>     def foo(x)
>         return "Posted to", x
>
> This is definitely not functional code, but might get you in the right
> direction on __getattribute__.  __getattr__ might also work for you.  I
> haven't worked too much with these corners of python.
>
> Cheers,
> Cliff

Hey, Cliff.  Thanks for sharing this idea.  Unfortunately, providing a
way to actually call the method with the mangled name is relatively
easy, and there are options there.  The real issue, to me, seems to be
finding a way to prevent Python from eating all but the last version
of a function definition in a class.  While decorators are a elegant
and unintrusive approach, I don't believe that there is any way for a
decorator to collection information in a data structure and then
provide that data back to the class instance or the class's metaclass.

I'm beginning to think that I am trying to get the square peg of
Python to fit into the round hole of a .NET idiom.  I am trying to
borrow what I think is a really elegant and useful idiom from ASP.NET
MVC.  Specifically, in an ASP.NET MVC Controller class, I can have two
methods with the same name that are called for different HTTP Verbs by
applying an Attribute:

public ActionResult Payment() {
ViewData["Title"] = "Payment Information";
ViewData["submit_text"] = "Next >";

return View();
}

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Payment(FormCollection form) {

return RedirectToAction("Legal");
}

Right?  The first Payment method is called when the Payment page is
rendered.  The second is called when the form that it contains is
submitted.  I find it to be readable, elegant and it does not intrude
into the actual logic of the method itself.  The alternatives that I
can readily identify are less-than-optimal.  For instance, if could
just have an if statement inside the body of the method that branches
on the HTTP verb:

def Payment(self):
if self.request.verb == 'GET':
# Do stuff for GET
elif self.request.verb == 'POST':
# So stuff for POST

Yes, it would work, but it is ugly and requires me to mix in the same
function the behaviors for two very separate things.

Or, I could do something like this:

def GET_Payment(self):
# Do stuff for GET

def POST_Payment(self):
# Do stuff for POST

This is trivially-easy to implement (in this case, a metaclass can
very easily manipulate the namespace), but it makes the source code
less appealing and just feels crufty and hacky.  It also makes it
difficult to deal elegantly with having one method respond to more
than verb like I could if I could write:

@GET
@POST
def foo(self):
# Do stuff for page foo, if it is GET or POST; PUT and DELETE not
allowed!

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Re: Style formating of multiline query, advise

2009-03-18 Thread someone

On Mar 18, 2:51 pm, John Machin  wrote:
> On Mar 18, 11:25 pm, someone  wrote:
>
> > Hi,
>
> > what is good :) style for multiline queries to database?
> > Is that one ok?
> > query = """ SELECT * FROM (
> >                    SELECT a.columna, a.columnb, a.iso
> >                       FROM all a
> >                       WHERE (a.name = LOWER(%s))  ) AS c
> >                  JOIN other as b on c.gid = b.id
> >                  WHERE class = 'A'
> >                  ORDER BY population DESC
> >                  LIMIT %s;"""
>
> There's no tablet of stone, like PEP 8 :-) It seems to be a matter of
> individual taste; clarity and consistency and not overdoing
> parentheses count for me.
>
> IMO you have too much leading whitespace, you have "as" in upper,

thanks for reply.
So, no indentation? query is inside of function, of course.

> lower and no case, and I'd set out the inner select differently:
>
> query = """
>     SELECT * FROM (
>         SELECT a.columna, a.columnb, a.iso
>         FROM all AS a
>         WHERE a.name = LOWER(%s)
>         ) AS c
>     JOIN other AS b ON c.gid = b.id
>     WHERE class = 'A'
>     ORDER BY population DESC
>     LIMIT %s;
> """
>
> Cheers,
> John



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Re: 2to3 does not fix FileType from types Module; no replacement?

John Roth  wrote:
> On Mar 18, 5:48 am, Benjamin Peterson  wrote:
> >   tlink.de> schrieb:
> >
> > > and I could not find a replacement for 'FileType'.
> > > Has this been overlooked?
> >
> > > Found this thread which does not mention FileType:
> > >http://mail.python.org/pipermail/stdlib-sig/2008-April/thread.html#172
> >
> > > I guess I just did not see something simple.
> > > Anyone with a hint?
> >
> > That's because this isn't simple. Python 3 doesn't have one file type. It 
> > has
> > several different kinds of streams in the io module. If you're checking for 
> > a
> > file type, you'll want to use isinstance(some_file, io.IOBase). If you're
> > inheriting form it, I suggest you look at the io module's classes.
> 
> Nontheless, a warning would be helpful, possibly with some doc.

Submitting an issue to the tracker with this request would probably be a
good idea.  Even better if you include a suggested patch.

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smtplib problem with newly rebuilt Debian/lenny system

2009-03-18 Thread cassiope

A hard drive failure forced me to rebuild my main system.  Just a few
things haven't been restored; one of them is a python script which is
used to email users of important events.

In attempting to diagnose the cause, I tried directly executing the
lines inside the python2.5 interpreter:

import  smtplib
s= smtplib.SMTP('localhost')

but the second line causes  a traceback:

File "", line 1, in 
File "/usr/lib/python2.5/smtplib.py", line 244, in __init__
(code, msg) = self.connect(host, port)
File "/usr/lib/python2.5/smtplib.py", line 310, in connect
raise socket.error, msg
socket.error: (97, 'Address family not supported by protocol')

This is with exim4 and python2.5 on a newly installed lenny system.
No error messages appear in /var/log or /var/log/exim4 directories.

Helpful clues or pointers to relevant documentation would be
appreciated!

-f
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Re: Style formating of multiline query, advise

2009-03-18 Thread someone

On Mar 18, 4:04 pm, Tino Wildenhain  wrote:
> John Machin wrote:
> > On Mar 18, 11:25 pm, someone  wrote:
> >> Hi,
>
> >> what is good :) style for multiline queries to database?
> >> Is that one ok?
> >> query = """ SELECT * FROM (
> >>                    SELECT a.columna, a.columnb, a.iso
> >>                       FROM all a
> >>                       WHERE (a.name = LOWER(%s))  ) AS c
> >>                  JOIN other as b on c.gid = b.id
> >>                  WHERE class = 'A'
> >>                  ORDER BY population DESC
> >>                  LIMIT %s;"""
>
> > There's no tablet of stone, like PEP 8 :-) It seems to be a matter of
> > individual taste; clarity and consistency and not overdoing
> > parentheses count for me.
>
> > IMO you have too much leading whitespace, you have "as" in upper,
> > lower and no case, and I'd set out the inner select differently:
>
> > query = """
> >     SELECT * FROM (
> >         SELECT a.columna, a.columnb, a.iso
> >         FROM all AS a
> >         WHERE a.name = LOWER(%s)
> >         ) AS c
> >     JOIN other AS b ON c.gid = b.id
> >     WHERE class = 'A'
> >     ORDER BY population DESC
> >     LIMIT %s;
> > """

Agree, that looks nicer
>
> And I'd not recomment SELECT * for anything beside test queries in an
> interactive session or if you are going to copy tables...

yes, it I know.

Thank you for responce!

>
> Regards
> Tino
>
>  smime.p7s
> 4KViewDownload

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Re: objectoriented -?- functional

2009-03-18 Thread Gerard Flanagan


Walther Neuper wrote:

 >>> def reverse_(list):
... """list.reverse() returns None; reverse_ returns the reversed 
list"""

... list.reverse()
... return list
...
 >>> ll = [[11, 'a'], [33, 'b']]
 >>> l = ll[:]  # make a copy !
 >>> l = map(reverse_, l[:])  # make a copy ?
 >>> ll.extend(l)
 >>> print("ll=", ll)
('ll=', [['a', 11], ['b', 33], ['a', 11], ['b', 33]])

But I expected to get ...
('ll=', [[11, 22], [33, 44], [22, 11], [44, 33]])
... how would that elegantly be achieved with Python ?



Your example isn't clear, but you may be better off using list 
comprehensions and the builtin 'reversed' function (though I don't know 
if it is available in 2.4).


Some code if it helps:

a = [1, 2, 3]
b = [a, a, a]
print [list(reversed(X)) for X in b]
[[3, 2, 1], [3, 2, 1], [3, 2, 1]]

grid = [
[1, 2, 3],
[6, 5, 4],
[7, 8, 9],
]
print [list(reversed(X)) if i % 2 else X for i, X in enumerate(grid)]
[[1, 2, 3], [4, 5, 6], [7, 8, 9]]

def revers_(seq):
seq = seq[:]
seq.reverse()
return seq

print a
[1, 2, 3]

print revers_(a)
[3, 2, 1]
print a
[1, 2, 3]


print b
[[1, 2, 3], [1, 2, 3], [1, 2, 3]]
print map(revers_, b)
[[3, 2, 1], [3, 2, 1], [3, 2, 1]]
print b
[[1, 2, 3], [1, 2, 3], [1, 2, 3]]


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Re: Python to Perl transalators

2009-03-18 Thread Nick Craig-Wood

Armin  wrote:
>  On Wednesday 18 March 2009 11:01:00 Boris Borcic wrote:
> > Armin wrote:
> > >> 
> > >> Why on earth would you want to? That'd be like translating Shakespeare
> > >> into a bad rap song!
> > >> 
> > >
> > > lol, actually I would prefer a rap song over Shakespeare, so your analogy
> > > doesn't work there ;)
> >
> > Why, some people do prefer Perl over Python, so what's wrong with the
> > analogy ?
> >
> 
>  That would mostly apply to people who haven't coded in Python for one reason 
>  or another.

Perhaps the OP is looking for something like this

  http://pleac.sourceforge.net/pleac_python/index.html

Which is a sort of Rosetta stone for perl and python ;-)

(The perl cookbook translated into python.)

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Re: Mangle function name with decorator?

2009-03-18 Thread Adam

On Mar 18, 11:11 am, "R. David Murray"  wrote:
> I don't have any wisdom on the metaclass/decorator stuff, but what
> about slightly reformulating the interface?  Instead of having the
> programmer type, eg:
>
>     @GET
>     def foo(self): pass
>
>     @POST
>     def foo(self): pass
>
> have them type:
>
>     def GET_foo(self): pass
>     def POST_foo(self): pass
>
> It's even one less character of typing (the  :)
>
> --
> R. David Murray          http://www.bitdance.com

David, would you believe that I just posted about this very idea,  It
doesn't seem to have shown up yet, though.  This idea works from the
perspective of being trivially easy to implement.  I can easily write
a metaclass that looks in the namespace for methods with names that
start with GET_or POST_, or I can override __getattribute__ to do the
look up that way.  However, there are a couple of weaknesses that I
see with this approach.

First, from a purely aesthetic point of view, prepending the desired
verb to the method name just looks a bit ugly.  Also, it makes it
difficult to deal elegantly with avoiding duplicating code when one
piece of logic should dealing with more than one verb.  So, if I want
to have one method that works for GET and POST, I can do this:

def GET_foo(self):
# Do stuff for GET

def POST_foo(self):
return self.GET_foo()

but then I feel like I am cluttering my controller code with unneeded
functions when writing
@GET
@POST
def foo(self):
   # Blah blah blah

would be so much neater.

Or, I could allow method signatures like:
def GET_POST_foo(self):
   # Blah, blah, blah

But now my code to parse and manipulate or do lookups on methods names
is much more complicated.  Also, it introduces difficult ambiguities
in the case that an action of the controller has the same name as an
HTTP Verb.  These ambiguities can be coded around, but doing so makes
the code more-and-more crufty and prone to breakage.  I don't want to
build too much of a Rube Goldberg machine here, right?  What I really
want to do is use Python's metaprogamming facilities to provide an
elegant solution to a problem.  Unfortunately, I really don't think
that it is going to work out in any way that is really satisfying.
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Re: Mangle function name with decorator?

2009-03-18 Thread Michele Simionato

On Mar 18, 4:18 pm, Adam  wrote:
> Hey, Cliff.  Thanks for sharing this idea.  Unfortunately, providing a
> way to actually call the method with the mangled name is relatively
> easy, and there are options there.  The real issue, to me, seems to be
> finding a way to prevent Python from eating all but the last version
> of a function definition in a class.

As I said in my other post in this thread, this can only be done in
Python 3.X.
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Re: Strange crash issue on Windows w/ PyGTK, Cairo...

2009-03-18 Thread bieffe62

On Mar 18, 2:33 pm, CJ Kucera  wrote:
> [email protected] wrote:
> > It looks like some of the C extension you are using is causing a
> > segfault or similar in python
> > interpreter (or it could be a bug in the interpreter itself, but it is
> > a lot less likely).
>
> Okay...  I assume by "C extension" you'd include the PyGTK stuff, right?
> (ie: pycairo, pygobject, and pygtk)  Those are the only extras I've got
> installed, otherwise it's just a base Python install.
>
> Would a bad extension really cause this kind of behavior though?
> Specifically the working-the-first-time and crash-subsqeuent-times?  Do
> C extensions contribute to the bytecode generated while compiling?
>

If you have worked with C/C++, you know that memory-related bugs can
be very tricky.
More than once - working with C code - I had crashes that disappeared
if I just added
a 'printf', because the memory allocation scheme changed and the
memory corrupted was not anymore
relevant.

Ciao

FB
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Re: SOAPpy help needed

2009-03-18 Thread Piet van Oostrum

> somemilk  (D) wrote:

>D> Hi everyone.
>D> I have a PHP script which works and i need to write the same in Python
>D> but SOAPpy generates a slightly different request and i'm not sure how
>D> to fix it so the server likes it.

>D> The request generated by php script looks like this (removed http's
>D> from links):

>D> 
>D> D> xmlns:SOAP-ENV="schemas.xmlsoap.org/soap/envelope/"
>D> xmlns:ns1="marketing.ews.yahooapis.com/V4"
>>> 
>D> 
>D> *
>D> *
>D> *
>D> 6674262970
>D> *
>D> 
>D> 
>D> 
>D> 6674262970
>D> false
>D> 
>D> 
>D> 

>D> When trying to make the same using SOAPPy i get this request:

>D> 
>D> D> SOAP-ENV:encodingStyle="schemas.xmlsoap.org/soap/encoding/"
>D> xmlns:xsi="w3.org/1999/XMLSchema-instance"
>D> xmlns:SOAP-ENV="schemas.xmlsoap.org/soap/envelope/"
>D> xmlns:xsd="w3.org/1999/XMLSchema"
>>> 
>D> 
>D> *
>D> *
>D> *
>D> 6674262970
>D> *
>D> 
>D> 
>D> 
>D> False
>D> 6674262970
>D> 
>D> 
>D> 

>D> A slightly different request but i guess it should work but i get an
>D> error from the server: "Account ID specified in the header does not
>D> match the one specified in the parameter."

>D> But they do match!

>D> The only thing i see is some difference in namespaces, but i have no
>D> idea what to do right now. Please help.

I see two differences. I don't think the namespaces are a problem. The
declarations are in different locations but that should not matter. The
real differences are:
1. The order of the parameters is different. This could well be the
   problem if the server is not paying attention to the parameter names
   but only to the order.
2. The types are included in Python. this is the RPC.encoded convention
   rather than RPC/literal. RPC/encoded is not WS-I compliant and I
   don't think SOAPpy supports it.

Actually I would guess number 1 is the culprit. Maybe you could use a
different SOAP implementation, e.g. suds
(https://fedorahosted.org/suds/). I haven't used it myself but had it
recommended by some of my students who used it for a project.
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URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4]
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Re: Mangle function name with decorator?

2009-03-18 Thread andrew cooke

Adam wrote:
> Hey, Cliff.  Thanks for sharing this idea.  Unfortunately, providing a
> way to actually call the method with the mangled name is relatively
> easy, and there are options there.  The real issue, to me, seems to be
> finding a way to prevent Python from eating all but the last version
> of a function definition in a class.  While decorators are a elegant
> and unintrusive approach, I don't believe that there is any way for a
> decorator to collection information in a data structure and then
> provide that data back to the class instance or the class's metaclass.

way back i suggested you look at the property decorator.  that does a very
similar job, in that it combines three different methods into one.  it
does that by using a class as decorator and accumulating the methods in
the class.  as a side effect/bonus it has a curious syntax (you could make
this extensible by overriding getattr on the decorator).  so you would end
up with something like:

class Foo:

  @GET or @multi_dispatch('GET') or @multi.GET or something...
  def foo(...):
...

  @foo.POST
  def foo_post(...):
...

  @foo.DELETE
  def foo_delete(...):
...

another idea, which i have never tried, is to look at the metaclass and
intercept duplicate names there (perhaps by substituting the class
dictionary.

you are trying to do very "deep" things that most people do not do with
python.  that does not mean that there are no solutions, just that you
have to find them yourself (especially with the decline of this
newsgroup).

andrew

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Re: How to do this in Python? - A "gotcha"


Jim Garrison wrote:

Luis Zarrabeitia wrote:

On Tuesday 17 March 2009 06:04:36 pm Jim Garrison wrote:
with open(filename, "rb") as f:
for buf in iter(lambda: f.read(1000),''):
do_something(buf)


This is the most pythonic solution yet.

Thanks to all the responders who took time to ponder this seemingly
trivial question.  I learned a lot about the Python mind-set.


I just tried the code as given above and it results in an infinite loop.

Since f.read() returns a byte string when in binary mode, the sentinel
has to be b''.  Is there a value that will compare equal to both '' and b''?

It's a shame the iter(o,sentinel) builtin does the
comparison itself, instead of being defined as iter(callable,callable)
where the second argument implements the termination test and returns a
boolean.  This would seem to add much more generality... is
it worthy of a PEP?

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Re: array next pointer

Duncan Booth  wrote:
> Armin  wrote:
> 
> > Could you give an example of next() with a sentinel and describe its
> > use case please?  I have a little trouble understanding what you guys
> > mean! 
> 
> It means you don't have to worry about next() throwing StopIteration. 
> 
> e.g.
> >>> def pairs(sequence, padding=None):
>   sequence = iter(sequence)
>   for a in sequence:
>   b = next(sequence, padding)
>   yield a, b
> 
>   
> >>> list(pairs('abcd'))
> [('a', 'b'), ('c', 'd')]
> >>> list(pairs('abcde'))
> [('a', 'b'), ('c', 'd'), ('e', None)]

That's using the next parameter for its primary purpose: supplying a default.
The sentinel sub-case might be something like this:

SENTINEL = object()
while somecondition:
#do something
val = next(someiterator, SENTINEL)
if val is SENTINEL: break
#do something with val

In most cases you'd refactor code like that into a generator or something,
but there are cases where a pattern like the above can be useful.  The
idea is that next will only return SENTINEL when the iterator is exhausted.
If you didn't use the SENTINEL, then StopIteration would be raised.  So you
could write the above as:

try: val = next(someiterator)
except StopIteration: break

but the version using SENTINEL avoids having the interpreter do the work
of generating a traceback, and is IMO slightly prettier.

I'm sure there are other use cases, too, but probably not a huge number
of them.  Certainly not as many as using the parameter as a default.

--
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Re: How to do this in Python? - A "gotcha"

2009-03-18 Thread Andrii V. Mishkovskyi

On Wed, Mar 18, 2009 at 5:51 PM, Jim Garrison  wrote:
> Jim Garrison wrote:
>>
>> Luis Zarrabeitia wrote:
>>>
>>> On Tuesday 17 March 2009 06:04:36 pm Jim Garrison wrote:
>>> with open(filename, "rb") as f:
>>>    for buf in iter(lambda: f.read(1000),''):
>>>        do_something(buf)
>>
>> This is the most pythonic solution yet.
>>
>> Thanks to all the responders who took time to ponder this seemingly
>> trivial question.  I learned a lot about the Python mind-set.
>
> I just tried the code as given above and it results in an infinite loop.
>
> Since f.read() returns a byte string when in binary mode, the sentinel
> has to be b''.  Is there a value that will compare equal to both '' and b''?
>
> It's a shame the iter(o,sentinel) builtin does the
> comparison itself, instead of being defined as iter(callable,callable)
> where the second argument implements the termination test and returns a
> boolean.  This would seem to add much more generality... is
> it worthy of a PEP?

Just before you start writing a PEP, take a look at `takewhile'
function in `itertools' module. ;)

>
> --
> http://mail.python.org/mailman/listinfo/python-list
>



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Re: objectoriented -?- functional

2009-03-18 Thread Piet van Oostrum

> Walther Neuper  (WN) wrote:

>WN> Hi,
>WN> loving Java (oo) as well as SML (fun) I use to practice both of them
>WN> separately.
>WN> Now, with Python I would like to combine 'oo.extend()' with 'functional
>WN> map':

>WN> Python 2.4.4 (#2, Oct 22 2008, 19:52:44)
>WN> [GCC 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)] on linux2
>WN> Type "help", "copyright", "credits" or "license" for more information.
> def reverse_(list):
>WN> ... """list.reverse() returns None; reverse_ returns the reversed
>WN> list"""
>WN> ... list.reverse()
>WN> ... return list
>WN> ...
> ll = [[11, 'a'], [33, 'b']]
> l = ll[:]  # make a copy !
> l = map(reverse_, l[:])  # make a copy ?
> ll.extend(l)
> print("ll=", ll)
>WN> ('ll=', [['a', 11], ['b', 33], ['a', 11], ['b', 33]])

>WN> But I expected to get ...
>WN> ('ll=', [[11, 22], [33, 44], [22, 11], [44, 33]])
>WN> ... how would that elegantly be achieved with Python ?

I guess you later changed 22 to 'a' and 44 to 'b'.

You have made a copy of the outer list with ll[:] (actually twice) but
you have not made copies of the inner lists and these are the important
ones. So the reverse will reverse the *original* inner lists which are
both in ll and in l.

If you still want to do destructive reverses on the inner list you
should make a deep copy:

>>> import copy
>>> l = copy.deepcopy(ll)
>>> l
[[11, 'a'], [33, 'b']]
>>> ll.extend(l)
>>> ll
[[11, 'a'], [33, 'b'], ['a', 11], ['b', 33]]

But IMHO it would be better to use non-destructive reverses:

>>> ll
[[11, 'a'], [33, 'b']]
>>> l = [list(reversed(x)) for x in ll]
>>> l
[['a', 11], ['b', 33]]
>>> ll.append(l)
>>> ll
[[11, 'a'], [33, 'b'], [['a', 11], ['b', 33]]]

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Re: How to do this in Python? - A "gotcha"


Andrii V. Mishkovskyi wrote:

Just before you start writing a PEP, take a look at `takewhile'
function in `itertools' module. ;)


OK, after reading the itertools docs I'm not sure how to use it
in this context.  takewhile() requires a sequence, and turning
f.read(bufsize) into an iterable requires iter() (no?) which
wants to do its own termination testing.  The following kludge
would subvert iter()'s termination testing but this is starting
to look Perlishly byzantine.

with open(filename, "rb") as f:
for buf in itertools.takewhile( \
lambda b:b, \
iter(lambda: f.read(1000),None)):
do_something(buf)

As opposed to

with open(filename, "rb") as f:
for buf in iter(lambda: f.read(1000), lambda b:b)):
do_something(buf)

where iter(callable,callable) is defined to

1) call the first argument
2) pass the returned value to the second argument
3) yield the first result and continue if the return value
   from the second call is True, or terminate if False
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Re: Roulette wheel

2009-03-18 Thread Aahz

In article ,
Peter Otten  <[email protected]> wrote:
>mattia wrote:
>>
>> cpop += [nchromosome1] + [nchromosome2]
>
>I'd write that as 
>
>cpop.append(nchromosome1)
>cpop.append(nchromosome2)
>
>thus avoiding the intermediate lists.

You could also write it as

cpop += [nchromosome1, nchromosome2]

which may or may not be faster, substituting one attribute lookup, one
list creation, and one method call for two attribute lookups and two
method calls.  I shan't bother running timeit to check, but I certainly
agree that either your version or mine should be substituted for the
original, depending on one's esthetics (meaning that I doubt there's
enough performance difference either way to make that the reason for
choosing one).
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about it is at best rationalization of gut feelings, and at worst plain
wrong."  --GvR, python-ideas, 2009-3-1
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Re: How to do this in Python? - A "gotcha"

2009-03-18 Thread S Arrowsmith

Jim Garrison   wrote:
>It's a shame the iter(o,sentinel) builtin does the
>comparison itself, instead of being defined as iter(callable,callable)
>where the second argument implements the termination test and returns a
>boolean.  This would seem to add much more generality... is
>it worthy of a PEP?

class sentinel:
def __eq__(self, other):
return termination_test()

for x in iter(callable, sentinel()):
...

Writing a sensible sentinel.__init__ is left as an exercise

-- 
\S

   under construction

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Re: Style formating of multiline query, advise

2009-03-18 Thread Scott David Daniels


someone wrote:

what is good :) style for multiline queries to database?...
query = """ SELECT * FROM (
   SELECT a.columna, a.columnb, a.iso
  FROM all a
  WHERE (a.name = LOWER(%s))  ) AS c
 JOIN other as b on c.gid = b.id
 WHERE class = 'A'
 ORDER BY population DESC
 LIMIT %s;"""


Also, for SQL, (A) why are you using nested joins?, and
(B) always show what columns you want as output.  SELECT * is a hack
to make interactive use easier, not a durable way to write queries.

query = """SELECT a.columna, a.columnb, a.iso, b.id, ...
FROM all AS a, other as b
WHERE a.name = LOWER(%s)
 AND  a.gid = b.id
 AND  b.class = 'A'
ORDER BY population DESC
LIMIT %s;"""

--Scott David Daniels
[email protected]
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Re: Style formating of multiline query, advise

2009-03-18 Thread Steve Holden

Scott David Daniels wrote:
> someone wrote:
>> what is good :) style for multiline queries to database?...
>> query = """ SELECT * FROM (
>>SELECT a.columna, a.columnb, a.iso
>>   FROM all a
>>   WHERE (a.name = LOWER(%s))  ) AS c
>>  JOIN other as b on c.gid = b.id
>>  WHERE class = 'A'
>>  ORDER BY population DESC
>>  LIMIT %s;"""
> 
> Also, for SQL, (A) why are you using nested joins?, and
> (B) always show what columns you want as output.  SELECT * is a hack
> to make interactive use easier, not a durable way to write queries.
> 
> query = """SELECT a.columna, a.columnb, a.iso, b.id, ...
> FROM all AS a, other as b
> WHERE a.name = LOWER(%s)
>  AND  a.gid = b.id
>  AND  b.class = 'A'
> ORDER BY population DESC
> LIMIT %s;"""

In more modern syntax this would be

SELECT a.columna, a.columnb, a.iso, b.id, ...
FROM all AS a
 JOIN other AS b
   ON a.gid = b.id
 WHERE  a.name = LOWER(%s)
   AND  b.class = 'A'
ORDER BY population DESC
LIMIT %s;"""

or something similar. The fact that you don't write JOIN in your SQL
doesn't mean the database isn't performing a join to perform the query
... I agree the nested query was somewhat over the top.

regards
 Steve
-- 
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Holden Web LLC http://www.holdenweb.com/
Want to know? Come to PyCon - soon! http://us.pycon.org/

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Re: Style formating of multiline query, advise

2009-03-18 Thread someone

On Mar 18, 5:56 pm, Scott David Daniels  wrote:
> someone wrote:
> > what is good :) style for multiline queries to database?...
> > query = """ SELECT * FROM (
> >                    SELECT a.columna, a.columnb, a.iso
> >                       FROM all a
> >                       WHERE (a.name = LOWER(%s))  ) AS c
> >                  JOIN other as b on c.gid = b.id
> >                  WHERE class = 'A'
> >                  ORDER BY population DESC
> >                  LIMIT %s;"""
>
> Also, for SQL, (A) why are you using nested joins?, and

inner select produce smaller set which is then joined with other
table, kind a optimization

> (B) always show what columns you want as output.  SELECT * is a hack
> to make interactive use easier, not a durable way to write queries.

Yes, my original question was about formatting. It's not original
query (only a part).
 But thank you anyway!

>
> query = """SELECT a.columna, a.columnb, a.iso, b.id, ...
>      FROM all AS a, other as b
>      WHERE a.name = LOWER(%s)
>       AND  a.gid = b.id
>       AND  b.class = 'A'
>      ORDER BY population DESC
>      LIMIT %s;"""
>
> --Scott David Daniels
> [email protected]

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Re: How to do this in Python? - A "gotcha"


S Arrowsmith wrote:

Jim Garrison   wrote:

It's a shame the iter(o,sentinel) builtin does the
comparison itself, instead of being defined as iter(callable,callable)
where the second argument implements the termination test and returns a
boolean.  This would seem to add much more generality... is
it worthy of a PEP?


class sentinel:
def __eq__(self, other):
return termination_test()

for x in iter(callable, sentinel()):
...

Writing a sensible sentinel.__init__ is left as an exercise



If I understand correctly, this pattern allows me to create
an object (instance of class sentinel) that implements whatever
equality semantics I need to effect loop termination.  In the
case in point, then, I end up with

class sentinel:
def __eq__(self,other):
return other=='' or other==b''

with open(filename, "rb") as f:
for buf in iter(lambda: f.read(1000), sentinel())):
do_something(buf)

i.e. sentinel is really "object that compares equal to both ''
and b''".  While I appreciate how this works, I think the
introduction of a whole new class is a bit of overkill for
what should be expressible in iter()
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Re: How to do this in Python? - A "gotcha"

2009-03-18 Thread andrew cooke


have you looked in operators?  that might avoid the need for a class.

Jim Garrison wrote:
> S Arrowsmith wrote:
>> Jim Garrison   wrote:
>>> It's a shame the iter(o,sentinel) builtin does the
>>> comparison itself, instead of being defined as iter(callable,callable)
>>> where the second argument implements the termination test and returns a
>>> boolean.  This would seem to add much more generality... is
>>> it worthy of a PEP?
>>
>> class sentinel:
>> def __eq__(self, other):
>> return termination_test()
>>
>> for x in iter(callable, sentinel()):
>> ...
>>
>> Writing a sensible sentinel.__init__ is left as an exercise
>>
>
> If I understand correctly, this pattern allows me to create
> an object (instance of class sentinel) that implements whatever
> equality semantics I need to effect loop termination.  In the
> case in point, then, I end up with
>
>  class sentinel:
>  def __eq__(self,other):
>  return other=='' or other==b''
>
>  with open(filename, "rb") as f:
>  for buf in iter(lambda: f.read(1000), sentinel())):
>  do_something(buf)
>
> i.e. sentinel is really "object that compares equal to both ''
> and b''".  While I appreciate how this works, I think the
> introduction of a whole new class is a bit of overkill for
> what should be expressible in iter()
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>


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Re: How to do this in Python? - A "gotcha"

2009-03-18 Thread andrew cooke

sorry, ignore that.  hit send before thinking properly.

> have you looked in operators?  that might avoid the need for a class.


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Re: Mangle function name with decorator?

Adam  wrote:
> David, would you believe that I just posted about this very idea,  It
> doesn't seem to have shown up yet, though.  This idea works from the
> perspective of being trivially easy to implement.  I can easily write
> a metaclass that looks in the namespace for methods with names that
> start with GET_or POST_, or I can override __getattribute__ to do the
> look up that way.  However, there are a couple of weaknesses that I
> see with this approach.
> 
> First, from a purely aesthetic point of view, prepending the desired
> verb to the method name just looks a bit ugly.  Also, it makes it
> difficult to deal elegantly with avoiding duplicating code when one
> piece of logic should dealing with more than one verb.  So, if I want
> to have one method that works for GET and POST, I can do this:
> 
> def GET_foo(self):
> # Do stuff for GET
> 
> def POST_foo(self):
> return self.GET_foo()
> 
> but then I feel like I am cluttering my controller code with unneeded
> functions when writing
> @GET
> @POST
> def foo(self):
># Blah blah blah
> 
> would be so much neater.

def GET_foo(self):
#do stuff for GET/POST

POST_foo = GET_foo

> Or, I could allow method signatures like:
> def GET_POST_foo(self):
># Blah, blah, blah
> 
> But now my code to parse and manipulate or do lookups on methods names
> is much more complicated.  Also, it introduces difficult ambiguities
> in the case that an action of the controller has the same name as an
> HTTP Verb.  These ambiguities can be coded around, but doing so makes

Hmm.  I don't follow that.  GET_GET would seem to be unambiguous.

> the code more-and-more crufty and prone to breakage.  I don't want to
> build too much of a Rube Goldberg machine here, right?  What I really
> want to do is use Python's metaprogamming facilities to provide an
> elegant solution to a problem.  Unfortunately, I really don't think
> that it is going to work out in any way that is really satisfying.

Someone else suggested the property model, though that is probably not
as elegant as you want either.

Sohow about the below.  Extending it to handle multiple classes is
left as an exercise for the reader :)  As is extending it to handle
stacking the decorators.

--
R. David Murray   http://www.bitdance.com


registry = {}

def HTTP_decorator_factory(name):
def _(f):
registry['%s_%s' % (name, f.__name__)] = f
def _(self, *args, **kw):
return _dispatch(f.__name__, self, *args, **kw)
return _
return _

def _dispatch(name, self, *args, **kw):
return registry['%s_%s' % (self.mode, name)](self, *args, **kw)

GET = HTTP_decorator_factory('GET')
POST = HTTP_decorator_factory('POST')


class Controller(object):

def __init__(self, mode='GET'):
self.mode = mode

@POST
def foo(self):
print "in POST foo"

@GET
def foo(self):
print "in GET foo"


c1 = Controller(mode='GET')
c2 = Controller(mode='POST')

c1.foo()
c2.foo()

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How complex is complex?

2009-03-18 Thread Kottiyath

When we say readability counts over complexity, how do we define what
level of complexity is ok?
For example:
Say I have dict a = {'a': 2, 'c': 4, 'b': 3}
I want to increment the values by 1 for all keys in the dictionary.
So, should we do:
>>> for key in a:
...   a[key] = a[key] + 1
or is it Ok to have code like:
dict(map(lambda key: (key, a[key] + 1), a))

How do we decide whether a level of complexity is Ok or not?
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Openings for Python Programmer at CA

2009-03-18 Thread Aniket M

Hello ,
This is Aniket from Techclique, a New Jersey based software
development and IT consulting firm providing top quality technical and
software professionals on a permanent and contractual basis to
Government and commercial customer including fortune 500 companies and
most of states and federal governments. I am contacting you to see if
you are comfortable to the skills mentioned below, please forward
resume to this e-mail address [email protected]

Python Programmer (someone with industry knowledge/asset mgt)
Location: Newport Beach, CA (Need Local)
Duration: 6+ months
Note: Communication MUST be perfect!, Plus submit with 3 professional
references

Python programming skills (with web development and dynamically
generated charts/plots in particular) and working knowledge of Linux/
UNIX Shell Scripts and SQL.
Knowledge of Python integration with C/C++ - a definite plus.

Qualifications/Requirements
* 3+ years of Python programming on Linux/Unix platform; recent (2007)
required
* Programming skills building forms, lay-outs, charts, and graphing
required
* Designing, coding, and testing web based applications preferred.
* Strong organizational, oral and written communications skills
* High energy/self starter with the ability to work independently
within the firm*s demanding and highly focused environment


Thanks & Regards,
Aniket
Techclique Inc.
Jersey City, NJ
Email: [email protected]
Yahoo IM : [email protected]
Contact No : 732-357-3844
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Disable automatic interning

2009-03-18 Thread George Sakkis

Is there a way to turn off (either globally or explicitly per
instance) the automatic interning optimization that happens for small
integers and strings (and perhaps other types) ? I tried several
workarounds but nothing worked:

>>> 'x' is 'x'
True
>>> 'x' is 'x'+''
True
>>> 'x' is ''+'x'
True
>>> 'x' is 'x'*1
True
>>> 'x' is str('x')
True
>>> 'x' is str('x')+str('')
True
>>> 'x' is str.__new__(str,'x')
True


George
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Re: How complex is complex?

2009-03-18 Thread bearophileHUGS

Kottiyath:
> How do we decide whether a level of complexity is Ok or not?

I don't understand your question, but here are better ways to do what
you do:

>>> a = {'a': 2, 'c': 4, 'b': 3}
>>> for k, v in a.iteritems():
...   a[k] = v + 1
...
>>> a
{'a': 3, 'c': 5, 'b': 4}
>>> b = dict((k, v+1) for k, v in a.iteritems())
>>> b
{'a': 4, 'c': 6, 'b': 5}

The first modifies the dict in-place, and the second created a new
dict.

In Python 3 those lines become shorter:

for k, v in a.items():
{k: v+1 for k, v in a.items()}

Bye,
bearophile
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Re: How complex is complex?

2009-03-18 Thread Casey Webster

On Mar 18, 1:30 pm, Kottiyath  wrote:
> When we say readability counts over complexity, how do we define what
> level of complexity is ok?
> For example:
> Say I have dict a = {'a': 2, 'c': 4, 'b': 3}
> I want to increment the values by 1 for all keys in the dictionary.
> So, should we do:>>> for key in a:
>
> ...   a[key] = a[key] + 1
> or is it Ok to have code like:
> dict(map(lambda key: (key, a[key] + 1), a))
>
> How do we decide whether a level of complexity is Ok or not?

This isn't just a question of readability; the two expressions are
entirely different. The second expression creates a whole new
dictionary, which might not have been obvious to you given the overall
complexity of the expression. The first expression is simple, clear,
and other than maybe changing "a[key] = a[key] + 1" to "a[key] += 1"
is pretty much hard to improve on.  If the number of lines matters to
you (it shouldn't, be opinions vary), then you could always write:

>>> for k in a: a[k] += 1

Which is shorter and far easier to read than the dict/map/lambda
expression.  And probably what you really intended!
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Re: How complex is complex?

2009-03-18 Thread George Sakkis

On Mar 18, 1:30 pm, Kottiyath  wrote:

> When we say readability counts over complexity, how do we define what
> level of complexity is ok?
> For example:
> Say I have dict a = {'a': 2, 'c': 4, 'b': 3}
> I want to increment the values by 1 for all keys in the dictionary.
> So, should we do:>>> for key in a:
>
> ...   a[key] = a[key] + 1
> or is it Ok to have code like:
> dict(map(lambda key: (key, a[key] + 1), a))
>
> How do we decide whether a level of complexity is Ok or not?

The second alternative is:
- unreadable (took me 10 seconds to parse vs 1 for the former).
- slower (makes a function call on every round).
- broken (creates a new dict instead of modifying the original in
place).

Really, there's not much of a dilemma here.

George
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Re: How to do this in Python? - A "gotcha"

2009-03-18 Thread Luis Zarrabeitia


Quoting Jim Garrison :

> Jim Garrison wrote:
> > Luis Zarrabeitia wrote:
> >> On Tuesday 17 March 2009 06:04:36 pm Jim Garrison wrote:
> >> with open(filename, "rb") as f:
> >> for buf in iter(lambda: f.read(1000),''):
> >> do_something(buf)
> > 
> > This is the most pythonic solution yet.
> > 
> > Thanks to all the responders who took time to ponder this seemingly
> > trivial question.  I learned a lot about the Python mind-set.
> 
> I just tried the code as given above and it results in an infinite loop.
> 
> Since f.read() returns a byte string when in binary mode, the sentinel
> has to be b''.  Is there a value that will compare equal to both '' and b''?

Thank you for the correction.
It works in python2.5 (on my Debian, at least), but I can see why it doesn't in
python3.

> It's a shame the iter(o,sentinel) builtin does the
> comparison itself, instead of being defined as iter(callable,callable)
> where the second argument implements the termination test and returns a
> boolean.  

A shame indeed. The "takewhile" workaround is way too obfuscated, and to create
a new class only for this purpose is an overkill (and I'd also classify it as
obfuscated).

> This would seem to add much more generality... is
> it worthy of a PEP?

and, it wouldn't need to replace the current sentinel implementation... one
keyword argument, "predicate", would suffice.

+1.

Cheers,

-- 
Luis Zarrabeitia
Facultad de Matemática y Computación, UH
http://profesores.matcom.uh.cu/~kyrie


 Participe en Universidad 2010, del 8 al 12 de febrero de 2010
 La Habana, Cuba 
 http://www.universidad2010.cu
 
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Disable automatic interning