Re: os.system and quoted strings
Hello svata,
It is always better to compose your string before you send it as a
command.
try printing your command string out like this :
print 'gvim dir+fileName+".txt". You'll see what the problem is.
One possible solution is to compose your command string in the
following manner:
cmd = "gvim %s%s.txt" %(dir, fileName)
and simply call os.system with cmd.
os.system(cmd)
Here is a little more detail on string format specifiers
http://docs.python.org/lib/typesseq-strings.html
HTH
Sriram
On Feb 27, 7:24 am, "svata" <[EMAIL PROTECTED]> wrote:
> Hello,
>
> as I'm new to python I've stumbled accros os.system and its not very
> well documented usage.
>
> I use Win XP Pro and Python 2.5.
>
> Here is the code snippet:
>
> --
>
> import time
> import os
>
> dir = "C:\\Documents and Settings\\somepath\\"
> fileName = time.strftime("%d%m%Y")
> os.system('gvim dir+fileName+".txt"')
>
> ---
>
> The problem is that concatenated variable dir+fileName doesn't get
> expanded as expected.
>
> Is there anything I omitted?
>
> svata
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Re: book for a starter
Hi, If you have experience programming, just read the online tutorial at http://docs.python.org/tut/tut.html I find Python Essential Reference (3rd Edition) (Developer's Library) (Paperback) invaluable though. BTW I have the 2nd edition. Amazon link : http://www.amazon.com/gp/pdp/profile/A9N9B1L0O4BYJ/ref=cm_blog_dp_pdp/002-7062034-2980840 On Feb 27, 10:58 am, Bjoern Schliessmann wrote: > Wensui Liu wrote: > > I just start learning python and have a question regarding books > > for a newbie like me. > > http://wiki.python.org/moin/IntroductoryBooks > > > If you are only allowed to buy 1 python book, which one will you > > pick? ^_^. > > I'd pick a reference. YMMV. > > Regards, > > Björn (having been allowed to buy more than one Python book) > > -- > BOFH excuse #314: > > You need to upgrade your VESA local bus to a MasterCard local bus. -- http://mail.python.org/mailman/listinfo/python-list
urllib2 on Windows Vista
I'm running Python 2.4.3 on Windows Vista June CTP. I'm not able to
open any site using the urllib2 and related family of modules
Here's what I get
>>> import urllib2
>>> urllib2.urlopen("http://www.microsoft.com";)
Traceback (most recent call last):
File "", line 1, in ?
File "D:\python24\lib\urllib2.py", line 130, in urlopen
return _opener.open(url, data)
File "D:\python24\lib\urllib2.py", line 358, in open
response = self._open(req, data)
File "D:\python24\lib\urllib2.py", line 376, in _open
'_open', req)
File "D:\python24\lib\urllib2.py", line 337, in _call_chain
result = func(*args)
File "D:\python24\lib\urllib2.py", line 1021, in http_open
return self.do_open(httplib.HTTPConnection, req)
File "D:\python24\lib\urllib2.py", line 996, in do_open
raise URLError(err)
urllib2.URLError:
Is this a known issue on Windows Vista?
Thanks,
Sriram
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Re: urllib2 on Windows Vista
Rune Strand wrote: > My wil guess is that it is a firewall problem. Perhaps you'll have to > specify that python.exe is trusted. Tried that - it didn't work. I also tried turning off the User Account Control and ran as full administrator - that didn't work too. -- http://mail.python.org/mailman/listinfo/python-list
Re: editor for Python on Linux
Mladen Adamovic wrote: > Hi! > > I wonder which editor or IDE you can recommend me for writing Python > programs. I tried with jEdit but it isn't perfect. > Check out http://wiki.python.org/moin/PythonEditors. I personally use Emacs -- Sriram -- http://mail.python.org/mailman/listinfo/python-list
Module re, extract on string match
I am wondering if I can use re.search to extract from a particular
location in a string.
Example:
string1='/Users/sriram/folder1/folder2/folder3/folder4/folder5/file'
re.search ('folder3,string1)
Thanks,
Sriram
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Pexpect echoes twice for each read
For some reason, Using pexpect causes my output to echo twice when I
connect from my MAC Darwin (10.4) to Linux (CentOS release 5 ):
The program:
-
#!/usr/bin/python
# Automatic scp to remote host
# Input 1 : filename
# Input 2 : destination folder
# Input 3 : hostname
import pexpect
import sys,re
ssh_cmd = "ssh " + sys.argv[3]
ssh_handle = pexpect.spawn (ssh_cmd)
ssh_handle.logfile = sys.stdout
PROMPT = "\$\ $"
try:
ssh_handle.expect(PROMPT)
ssh_handle.sendline ("scp "+ sys.argv[1] +" [EMAIL PROTECTED]:" +
sys.argv[2] )
ssh_handle.expect("password:")
ssh_handle.sendline(" ")
ssh_handle.expect(PROMPT)
except pexpect.TIMEOUT:
ssh_handle.logfile.write("\n Pexpect timeout !!\n")
sys.exit(1)
except KeyboardInterrupt:
ssh_handle.logfile.write("\n User interrupt!\n")
sys.exit(2)
ssh_handle.close()
Output:
---
$ python pexpect_test.py replace_line_break.sh /tmp/ 10.5.254.18
Last login: Tue Sep 9 15:45:05 2008 from sriram-macbook.dhcp.2wire.com
$ scp replace_line_break.sh [EMAIL PROTECTED]:/tmp/
scp replace_line_break.sh [EMAIL PROTECTED]:/tmp/
[EMAIL PROTECTED]'s password:
replace_line_break.sh 100% 296 0.3KB/s 00:00
$ $
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standard libraries don't behave like standard 'libraries'
I guess why every programming language has some kind of a 'standard library' built in within it. In my view it must not be called as a 'library' at all. what it does is like a 'bunch of built-in programs ready-made to do stuff'. Lets see what a 'library' does: 1. offers books for customers 1.1 lets user select a book by genre, etc 1.2 lets user to use different books of same genre, etc 1.3 lets user to use books by same author, etc for different genre 2. keeps track of all the books + their genre 2.1 first knows what all books it has at present 2.2 when new book comes it is added to the particular shelf sorted by genre,author,edition, etc. 2.3 when books become old they are kept separately for future reference 2.4 very old books can be sent to a museum/discarded I guess no standard library does the minimum of this but wants to be called a library. As a python user I always wanted the standard library to have such features so the user/developer decides to use what set of libraries he want. consider the libraries for 2.5 ,2.6, 3K are all available to the user, the user selects what he wants with something like. use library 2.5 or use library 2.6 etc. The 2 main things that the library management interface has to do is intra library management and inter library management. intra library mgmt- consider books to be different libraries (standard, commercial, private, hobby, etc) inter library mgmt- consider books to be modules inside a library ( standard, commercial, private, hobby, etc) if somehow we could accomplish this kind of mother of a all plugin/ad- hoc system that is a real breakthrough. Advantages: 1. new modules can be added to the stream quickly 2. let the user select what he want to do 3. modules (that interdepend on each other) can be packed into small distribution and added to the stream quickly without waiting for new releases 4. solution to problems like py 2.x and 3.x 5. users can be up to date 6. documentation becomes easy + elaborate to users 7. bug managing is easy too 8. more feed back 9. testing also becomes easy 10. many more , i don't know.. you have to find. Python already has some thing like that __future__ stuff. but my question is how many people know that? and how many use that? most of them wait until old crust gets totally removed. that is bad for user and python. that is why problems like py2.x py3.x originate. If there is a newer book collection it must always be available at the library. i must not go to another library to get that book. These are just my views on the state of the standard libraries and to make them state-of-the-art..! ;) -- http://mail.python.org/mailman/listinfo/python-list
Re: standard libraries don't behave like standard 'libraries'
On Nov 12, 3:56 pm, "Diez B. Roggisch" wrote: > Sriram Srinivasan schrieb: > > > > > I guess why every programming language has some kind of a 'standard > > library' built in within it. > > In my view it must not be called as a 'library' at all. what it does > > is like a 'bunch of built-in programs ready-made to do stuff'. > > > Lets see what a 'library' does: > > > 1. offers books for customers > > 1.1 lets user select a book by genre, etc > > 1.2 lets user to use different books of same genre, etc > > 1.3 lets user to use books by same author, etc for different genre > > > 2. keeps track of all the books + their genre > > 2.1 first knows what all books it has at present > > 2.2 when new book comes it is added to the particular shelf sorted by > > genre,author,edition, etc. > > 2.3 when books become old they are kept separately for future > > reference > > 2.4 very old books can be sent to a museum/discarded > > > I guess no standard library does the minimum of this but wants to be > > called a library. > > > As a python user I always wanted the standard library to have such > > features so the user/developer decides to use what set of libraries he > > want. > > > consider the libraries for 2.5 ,2.6, 3K are all available to the user, > > the user selects what he wants with something like. > > > use library 2.5 or use library 2.6 etc. > > > The 2 main things that the library management interface has to do is > > intra library management and inter library management. > > > intra library mgmt- consider books to be different libraries > > (standard, commercial, private, hobby, etc) > > inter library mgmt- consider books to be modules inside a library > > ( standard, commercial, private, hobby, etc) > > > if somehow we could accomplish this kind of mother of a all plugin/ad- > > hoc system that is a real breakthrough. > > > Advantages: > > > 1. new modules can be added to the stream quickly > > 2. let the user select what he want to do > > 3. modules (that interdepend on each other) can be packed into small > > distribution and added to the stream quickly without waiting for new > > releases > > 4. solution to problems like py 2.x and 3.x > > 5. users can be up to date > > 6. documentation becomes easy + elaborate to users > > 7. bug managing is easy too > > 8. more feed back > > 9. testing also becomes easy > > 10. many more , i don't know.. you have to find. > > > Python already has some thing like that __future__ stuff. but my > > question is how many people know that? and how many use that? most of > > them wait until old crust gets totally removed. that is bad for user > > and python. that is why problems like py2.x py3.x originate. If there > > is a newer book collection it must always be available at the library. > > i must not go to another library to get that book. > > You are greatly oversimplifying things, and ignoring a *lot* of issues > here. The reason for __future__ is that it can *break* things if new > features were just introduced. Take the with-statement, reachable in > python2.5 throug > > from __future__ import with_statement > > It introduces a new keyword, which until then could be happily used as > variable name. > > So you can't arbirtarily mix code that is written with one or the other > feature missing. > > Then there is the issue of evolving C-APIs (or ABI), wich makes modules > incompatible between interpreters. > > And frankly, for most of your list I don't see how you think your > "approach" reaches the stated advantages. Why is documentation becoming > easier? Why bug managing? Why testing? > > I'm sorry, but this isn't thought out in any way, it's just wishful > thinking IMHO. > > Diez I don't know if you have used Dev-C++.<http://www.bloodshed.net/dev/ packages/index.html> It has a 'package management' mechanism for the standard libraries. please see the <http://devpaks.org/> webpage where all the packaged libraries are stored. In python we have the PyPI which is equivalent to the http://devpacks.org but in PyPI the packages are mostly user made applications. What I want is similar to PyPI but for the python standard libraries, so that they (libraries) are as add-on as possible. check this out too.. <http://molhanec.net/devcpphelp/packages.php> I guess you understand what I am thinking... and do pardon my english too.. -- Regards, Sriram. -- http://mail.python.org/mailman/listinfo/python-list
Re: standard libraries don't behave like standard 'libraries'
On Nov 12, 3:56 pm, "Diez B. Roggisch" wrote: > Sriram Srinivasan schrieb: > > > > > I guess why every programming language has some kind of a 'standard > > library' built in within it. > > In my view it must not be called as a 'library' at all. what it does > > is like a 'bunch of built-in programs ready-made to do stuff'. > > > Lets see what a 'library' does: > > > 1. offers books for customers > > 1.1 lets user select a book by genre, etc > > 1.2 lets user to use different books of same genre, etc > > 1.3 lets user to use books by same author, etc for different genre > > > 2. keeps track of all the books + their genre > > 2.1 first knows what all books it has at present > > 2.2 when new book comes it is added to the particular shelf sorted by > > genre,author,edition, etc. > > 2.3 when books become old they are kept separately for future > > reference > > 2.4 very old books can be sent to a museum/discarded > > > I guess no standard library does the minimum of this but wants to be > > called a library. > > > As a python user I always wanted the standard library to have such > > features so the user/developer decides to use what set of libraries he > > want. > > > consider the libraries for 2.5 ,2.6, 3K are all available to the user, > > the user selects what he wants with something like. > > > use library 2.5 or use library 2.6 etc. > > > The 2 main things that the library management interface has to do is > > intra library management and inter library management. > > > intra library mgmt- consider books to be different libraries > > (standard, commercial, private, hobby, etc) > > inter library mgmt- consider books to be modules inside a library > > ( standard, commercial, private, hobby, etc) > > > if somehow we could accomplish this kind of mother of a all plugin/ad- > > hoc system that is a real breakthrough. > > > Advantages: > > > 1. new modules can be added to the stream quickly > > 2. let the user select what he want to do > > 3. modules (that interdepend on each other) can be packed into small > > distribution and added to the stream quickly without waiting for new > > releases > > 4. solution to problems like py 2.x and 3.x > > 5. users can be up to date > > 6. documentation becomes easy + elaborate to users > > 7. bug managing is easy too > > 8. more feed back > > 9. testing also becomes easy > > 10. many more , i don't know.. you have to find. > > > Python already has some thing like that __future__ stuff. but my > > question is how many people know that? and how many use that? most of > > them wait until old crust gets totally removed. that is bad for user > > and python. that is why problems like py2.x py3.x originate. If there > > is a newer book collection it must always be available at the library. > > i must not go to another library to get that book. > > You are greatly oversimplifying things, and ignoring a *lot* of issues > here. The reason for __future__ is that it can *break* things if new > features were just introduced. Take the with-statement, reachable in > python2.5 throug > > from __future__ import with_statement > > It introduces a new keyword, which until then could be happily used as > variable name. > > So you can't arbirtarily mix code that is written with one or the other > feature missing. > > Then there is the issue of evolving C-APIs (or ABI), wich makes modules > incompatible between interpreters. > > And frankly, for most of your list I don't see how you think your > "approach" reaches the stated advantages. Why is documentation becoming > easier? Why bug managing? Why testing? > > I'm sorry, but this isn't thought out in any way, it's just wishful > thinking IMHO. > > Diez __future__ as you said helps in stop breaking things. what i suggest that if both the libraries (in yr case-with is defined in one and other with is not defined is a simple one) like py2.x and py3.x exists and i want to use 3.x features in the morning then in the evening i want to use 2.x or something like that just add on the library and i get the require functionality -- http://mail.python.org/mailman/listinfo/python-list
Re: standard libraries don't behave like standard 'libraries'
On Nov 12, 4:35 pm, "Diez B. Roggisch" wrote: > Sriram Srinivasan schrieb: > > > > > On Nov 12, 3:56 pm, "Diez B. Roggisch" wrote: > >> Sriram Srinivasan schrieb: > > >>> I guess why every programming language has some kind of a 'standard > >>> library' built in within it. > >>> In my view it must not be called as a 'library' at all. what it does > >>> is like a 'bunch of built-in programs ready-made to do stuff'. > >>> Lets see what a 'library' does: > >>> 1. offers books for customers > >>> 1.1 lets user select a book by genre, etc > >>> 1.2 lets user to use different books of same genre, etc > >>> 1.3 lets user to use books by same author, etc for different genre > >>> 2. keeps track of all the books + their genre > >>> 2.1 first knows what all books it has at present > >>> 2.2 when new book comes it is added to the particular shelf sorted by > >>> genre,author,edition, etc. > >>> 2.3 when books become old they are kept separately for future > >>> reference > >>> 2.4 very old books can be sent to a museum/discarded > >>> I guess no standard library does the minimum of this but wants to be > >>> called a library. > >>> As a python user I always wanted the standard library to have such > >>> features so the user/developer decides to use what set of libraries he > >>> want. > >>> consider the libraries for 2.5 ,2.6, 3K are all available to the user, > >>> the user selects what he wants with something like. > >>> use library 2.5 or use library 2.6 etc. > >>> The 2 main things that the library management interface has to do is > >>> intra library management and inter library management. > >>> intra library mgmt- consider books to be different libraries > >>> (standard, commercial, private, hobby, etc) > >>> inter library mgmt- consider books to be modules inside a library > >>> ( standard, commercial, private, hobby, etc) > >>> if somehow we could accomplish this kind of mother of a all plugin/ad- > >>> hoc system that is a real breakthrough. > >>> Advantages: > >>> 1. new modules can be added to the stream quickly > >>> 2. let the user select what he want to do > >>> 3. modules (that interdepend on each other) can be packed into small > >>> distribution and added to the stream quickly without waiting for new > >>> releases > >>> 4. solution to problems like py 2.x and 3.x > >>> 5. users can be up to date > >>> 6. documentation becomes easy + elaborate to users > >>> 7. bug managing is easy too > >>> 8. more feed back > >>> 9. testing also becomes easy > >>> 10. many more , i don't know.. you have to find. > >>> Python already has some thing like that __future__ stuff. but my > >>> question is how many people know that? and how many use that? most of > >>> them wait until old crust gets totally removed. that is bad for user > >>> and python. that is why problems like py2.x py3.x originate. If there > >>> is a newer book collection it must always be available at the library. > >>> i must not go to another library to get that book. > >> You are greatly oversimplifying things, and ignoring a *lot* of issues > >> here. The reason for __future__ is that it can *break* things if new > >> features were just introduced. Take the with-statement, reachable in > >> python2.5 throug > > >> from __future__ import with_statement > > >> It introduces a new keyword, which until then could be happily used as > >> variable name. > > >> So you can't arbirtarily mix code that is written with one or the other > >> feature missing. > > >> Then there is the issue of evolving C-APIs (or ABI), wich makes modules > >> incompatible between interpreters. > > >> And frankly, for most of your list I don't see how you think your > >> "approach" reaches the stated advantages. Why is documentation becoming > >> easier? Why bug managing? Why testing? > > >> I'm sorry, but this isn't thought out in any way, it's just wishful > >> thinking IMHO. > > >> Diez > > > __future__ as you said helps in stop breaking things. what i suggest > > that if both the libraries (in yr case-with is defined in one and > > othe
Re: standard libraries don't behave like standard 'libraries'
On Nov 12, 6:07 pm, "Diez B. Roggisch" wrote: > > ok let me make it more clear.. > > forget how you use python now.. i am talking about __futuristic__ > > python programming. > > > there is no more python2.x or python3.x or python y.x releases. there > > is only updates of python and standard library say 1.1.5 and 1.1.6. > > let the difference be an old xml library updated with a new regex > > support. > > > i am coding my program now. > > i want my application to be compatible with 1.1.5 library > > > use library 1.1.5 > > import blah form blahblah > > ... > > ... > > > i cannot use regex feature of xml in this application > > i then update my library in the evening > > now both the libraries are present in my system. > > now i try using the new feature > > > use library 1.1.6 #thats all now i get all features > > import blah from blahblah > > This is not futuristic, this is state of the art with PyPI & setuptools. > > You still haven't addressed all the issues that arise though, regarding > different python interpreter versions having different syntax and ABI. > > Diez haha... it would be awesome if they implement it in the 'future' .. i posted the same to [email protected], it seems the distutil is getting a big overhaul. (i hope they make a new uninstall option for setuptools n easy_install) they say there are many ways to do that using pkg tools... but python wants one and only one way- the python way. regarding issues: 1.security is always a issue 2. regarding problems like with statement you mentioned earlier.. i think there will be a basic feature set that is common for all versions of add-on libraries. 3.when you want the new feature you have to update your python interpreter use interpreter 1.5.2 may trigger the proper interpreter plugin(responsible for additional feature) to load and add functionality.. its simple to say but it is hard to make the compiler pluggable, may be they figure out. use library x.y.z while issuing this command the default interpreter has to automatically resolve dependencies of the core c/cpp static libraries and other shared libraries. so that must not be an issue. if they have implemented this much, dep solving is nothing. futuristic python may also contain an option for compiling a module into a static library. so we can code python libraries in python (mostly) itself. think of pypy. it is already state of the art. -- http://mail.python.org/mailman/listinfo/python-list
Re: standard libraries don't behave like standard 'libraries'
> You are describing a lending library, which is not the only sort of > library. My personal library doesn't do any of those things. It is just a > room with shelves filled with books. how i see is all libraries are libraries, for a personal library you are the only customer and you are the management too.! > Words in English can have more than one meaning. Horses run, > refrigerators run, and even though they don't have either legs or motors, > programs run too. The argument that code libraries don't behave like > lending libraries won't get you anywhere. first this is not an argument at all...i clearly stated these were my imaginations cum ideas. > Since library features are tied closely to the features available in the > Python interpreter, the way to use library 2.5 is to use Python 2.5. You > *might* be able to use library 2.5 with Python 2.6 or 2.4; you absolutely > won't be able to use it with Python 1.5 or 3.1. i am not talking about the past..past were experiences! that the developers had and what is happening today *might be* another experience for the future. -- http://mail.python.org/mailman/listinfo/python-list
Re: standard libraries don't behave like standard 'libraries'
> So all libraries written have to use the common subset, which - unless > things are *removed*, which with python3 actually happened - is always > the oldest interpreter. And if a feature goes away, they have to be > rewritten with the then common subset. you see that's the problem with py3. instead of slowly removing the features one by one till the end they made a jump. the problem is not with the jump but with other libraries/packages that depend on py2. what i felt was if the new version was available as soon as it is into the stream, developers/users try to use them and get accustomed. now they follow this. they have frozen py3 for may be 2-3 years so ppl would move slowly to py2.6 ,2.7, 2.8... most. also the corporate companies are the most influential. also a point to note: if new updates keep on coming (for eg. daily antivirus update) developers tend to accept and move on *easily*. i am not an expert in programming/interpreter design/library writing/ packaging. i just wanted the standard library *too* to be pluggable, not just the applications based on it. i am not even experienced in python to make bold accusations so all i can say is 'how it would be if?' and i always stick to one thing 'why not?'. > In other words: as a library writer, I can't use shiny, new & better > features, I'm stuck with the old stuff, and whenever the interpreter > evolves I have to rewrite even the old ones. Not appealing. Why develop > the interpreter at all then? if you are app developer you needn't rewrite anything. that is the main point here! just specifying the interpreter and library version is enough every thing has to work like magic. as the previous library&interpreter wont be removed (unless and until it is your will) u can use them. thats how everybody would like it to be. as for a library writer is concerned: as you say it depends on certain things like other libraries,interpreter,etc. but i would like to say that change is inevitable. if some core developer has to change something he might change. and if you have to update your library you have to. this applies to the interpreter too. what python now does is make every update work with the minimal set (giving minimal backward compatibility) plus the new features too. which is exactly the right thing. what i wanted is the users have to be aware now and then when of the modification, deletion, addition stuff not in every release as in py3k. then the whole backward incompatibility issue would be *dissolved* or what i mean is *diffused* and ppl dont even know that they have switched over to a very new thing. > In other words: the problem is solved by somehow solving the problem - > but not by a concrete solution you propose? as i told before i neither know the problem nor the solution. i just wrote my ideas/imagination down > PyPy is cool, but by far not advanced enough to replace external, > C-based libraries such as NUMPY and PyQt and whatnot. > > I don't say that the current situation is by any means ideal. There is a > lot to be said about package creation, distribution, installation, > removal, dependency handling, and even system-packaging-integration if > one likes. > > You IMHO just add another layer of complexity on top of it, without > proposing solutions to any of the layers in between, nor your new one - > namely, the interpreter version agnosticism. yes you are right. python has a lot of bindings to a lot of stuff. but it is the strength and weakness. not exactly pythons weakness but with the thing on the other side. yes it may be looking complex because most of the 'standard library' system was not designed to be adhoc/add- on/pluggable from the start. -- http://mail.python.org/mailman/listinfo/python-list
