pyvm 1.1
WHAT IS IT -- pyvm is an experimental python virtual machine with a compiler written in python. pyvm is very incomplete and does not care about backwards compatibility so you shouldn't use it unless: - you are interested in vm hacking. - you want to build another big program based on a fork of pyvm. - you have a lot of free time and you are very bored. WHERE IS IT --- http://students.ceid.upatras.gr/~sxanth/pyvm/ WHAT'S NEW -- In this release pyvm has real lightweight threads (co-routines). That is that there are two OS threads, one running the main interpreter loop and another one polling for file descriptors. When there is a blocking system call, the main interpreter thread passes a request to the polling thread and removes the co-routines from the running list. With this setup, pyvm can run unlimited python threads with just two OS threads. -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Re: Checking free disk space on Win32 ?
http://mail.python.org/pipermail/python-list/2001-January/025344.html -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I dynamically create functions without lambda?
Steven D'Aprano wrote: On Fri, 27 Jan 2006 11:41:56 -0800, Kay Schluehr wrote: Russell wrote: I want my code to be Python 3000 compliant, and hear that lambda is being eliminated. The problem is that I want to partially bind an existing function with a value foo that isn't known until run-time: someobject.newfunc = lambda x: f(foo, x) The reason a nested function doesn't work for this is that it is, well, dynamic. I don't know how many times or with what foo's this will be done. Now, I am sure there are a half-dozen ways to do this. I just want the one, new and shiny, Pythonic way. ;-) If you want to code partial application without lambda I recommend using the code presented in the accepted PEP 309 that will be implemented in the functional module in Python 2.5. http://www.python.org/peps/pep-0309.html Fascinating. A couple of thoughts: - I really wish that people would make up their minds about what currying is, and how it differs from partials and closures. If the people who do know can't agree, how do they expect the rest of us to understand? If they can't agree they probably don't know ;) Concepts like closure and currying are well defined in lambda calculus and hence in functional programming. - What, if anything, is the difference between a closure and an iterator? Is an iterator just a closure wrapped up with an API? I would expect a closure to be a function with free/unbound variables that are bound by an enclosing context. In FP slang a function without any free variables is called a combinator. An iterator is a function related to an abstract data type equipped with a partial order. The iterator abstracts from the particular ordering scheme and makes the ADT look like a list. In Python we have a nice correspondence between generators as implicit defined sequences of yielded values, iterators that enable uniform access to the values produced by generators and lists that make the sequence explicit ( if finite ). Fun with combinators == There are quite interesting relationships deep down in the theory of computation. For instance understanding recursion in lambda calculus is not that easy because you cannot simply reintroduce an anonymous function by the name into its own body. The idea is to create a fixpoint of a higher order curried function instead. See for example this curried extension of a factorial: F = lambda h: lambda n : n2 and 1 or n*h(n-1) Now imagine you have a fixpoint fix(F) of F which is again a function and pass it into F then you will get: fix(F) = F(fix(F)) = lambda n : n2 and 1 or n*fix(F)(n-1) That is fix(F) is actually the searched factorial ! There is a generic way to create fixpoints of higher order curried functions such as F. The most popular one is the so called Y-combinator ( not to confuse with Paul Grahams company ;). In Python you can write: Y = lambda g: (lambda f: g(lambda arg: f(f)(arg))) (lambda f: g(lambda arg: f(f)(arg))) This serves the purpose. Try Y(F) and see. Kay -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs C for a mail server
but i am not able to choose the language.Should i go for C(socket API) Ravi is right (using sockets is more or less the same from any language.) ..try JSP(java server pages), some guys in nit warangal implemented a mail server (foa LAN though)for their minor project. my contention is that using sockets(in c++) will improve your understanding of the protocol suite and improve your programming as well. Ravi Teja wrote: Why don't you use an existing mail server? Probably because that was his homework assignment for a networking class. Not uncommon to be told to implement a server from the scratch from the RFC. Although that does not explain his concern about performance. Abhinav, if that is the case, using sockets is more or less the same from any language. Python as usual will be cleaner than C. You might want to look at Twisted Mail. Use SocketServer module in the standard library to implement the RFC. Other than that it is silly to try to write a Mail Server unless you have some extra ordinary need. -- http://mail.python.org/mailman/listinfo/python-list
Re: VB to Python migration
I second the suggestion of using Boo for this case. Why use Delphi or VB when you have a more pythonic first class .NET language? You already have a very good IDE for creating your project (SharpDevelop), which is free, open source and already has the Boo bindings included (download here the latest version: http://build.sharpdevelop.net/BuildArtefacts/). Boo is a perfect language for someone wanting to develop Windows GUI apps because it has all the nice features and syntax of Python, while being specifically created to run on the .NET framework. However, if you still want to use pure Python, it won't take too long to get what you need. Ironpython is in version 1.0 Beta 2, and moving full steam towards a stable release. I'm sure that soon it will be integrated to Visual Studio. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs C for a mail server
In article [EMAIL PROTECTED], Ravi Teja [EMAIL PROTECTED] wrote: Why don't you use an existing mail server? Probably because that was his homework assignment for a networking class. Not uncommon to be told to implement a server from the scratch from the RFC. Although that does not explain his concern about performance. Abhinav, if that is the case, using sockets is more or less the same from any language. Python as usual will be cleaner than C. You might want to look at Twisted Mail. Use SocketServer module in the standard library to implement the RFC. Other than that it is silly to try to write a Mail Server unless you have some extra ordinary need. Any lecturer assigning write a mail server as a class project is doing his/her students a true dis-service. Mail server RFC compliance is a nightmare to get right, performance issues and mail routeing are both material for at least a full year's university study. A student who tries to make an even vaguely RFC compliant mail server probably won't finish their project, as student who completes such a project might come away with the mistaken belief that they actually have done it correctly. The number of software products which use eail and do so incorrectly is astounding and depressing. There's a reason that the source for sendmail is about 120K lines, exim is nearly 270K lines. Doing it right is _hard_. -- Jim Segrave ([EMAIL PROTECTED]) -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs C for a mail server
jim you are probably right. i have had exp. with this. i had to create a server(multipurpose such as file sharing, games (pretty simple tho like tic tac toe..) we were in 6th sem with learning OS and comp. n/w for the first time. it seems like these jack ass jerks (proffs/instuctors) like to bully students... obviously we cud not complete the project as most of the time was spent on learning the stuff(like TCP, multithreading..) . i don't know how things work out in the west, but i feel the faculty really care about their students in american colleges..in contrast to here (in inida, though things are little different in the IITs) Jim Segrave wrote: In article [EMAIL PROTECTED], Ravi Teja [EMAIL PROTECTED] wrote: Why don't you use an existing mail server? Probably because that was his homework assignment for a networking class. Not uncommon to be told to implement a server from the scratch from the RFC. Although that does not explain his concern about performance. Abhinav, if that is the case, using sockets is more or less the same from any language. Python as usual will be cleaner than C. You might want to look at Twisted Mail. Use SocketServer module in the standard library to implement the RFC. Other than that it is silly to try to write a Mail Server unless you have some extra ordinary need. Any lecturer assigning write a mail server as a class project is doing his/her students a true dis-service. Mail server RFC compliance is a nightmare to get right, performance issues and mail routeing are both material for at least a full year's university study. A student who tries to make an even vaguely RFC compliant mail server probably won't finish their project, as student who completes such a project might come away with the mistaken belief that they actually have done it correctly. The number of software products which use eail and do so incorrectly is astounding and depressing. There's a reason that the source for sendmail is about 120K lines, exim is nearly 270K lines. Doing it right is _hard_. -- Jim Segrave ([EMAIL PROTECTED]) -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs C for a mail server
ya its supposed to be some stupid 6 month project which my friend has to do.I am just helping him out.he may not be implementing a full fledged rfc compliance mail server but may support some of the major functionalities.so basically its an extra ordinary need.I just wanted to know which language would be better for implementation and has faster development cycle.I have heard a lot about python and its ease of use.My point is it should be worth a 6 month project and speedy development since he is already proficient in C/C++ socket programming and taking the pain of learning python should be worth the effort. -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I tell if I'm running in the PyWin interpreter?
Charles Krug wrote: Is there a way to detect that I'm running the the PyWin interpreter so that I can bypass its raw_input behavior? You could test if pywin_specific_module in sys.modules: # use workaraound Or maybe you can get away with always using sys.stdin.readline() instead of raw_input()? Look into cmd.py for an example. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Returning a value from code string
Fredrik Lundh wrote:
executing the code in a custom namespace is a lot cleaner:
ns = {}
ns[os] = os # insert preimported values
ns[app] = app # insert preloaded objects
exec self.code in ns
try:
func = ns[std_func_name]
except KeyError:
pass
else:
func(**kwargs)
instead of using a standard function, you can let the code
objects talk to the application via a preloaded object or an
interface module. e.g. instead of
def std_func_name(app, args):
app.something()
your code object could simply become
app.something()
These code objects should all return an instance of a certain class (or
one of its descendants). In another branch of this topic, I described
roughly what this is for. So, without going into too much detail, I'll
just repeat that this is for a website backend. Whenever an HTML form is
submitted, a hidden op element (short for operation) in the form is
checked. This value will send the rest of the form data on to the code
object it represents. (If you've read my other post: These code objects
are nodes, the value for the op element is the ID number of one of
them, or possibly one of a few mnemonics for some of the more important
ops.)
So, taking another swipe at it with your suggestions:
def __call__(self, args=None, **kwargs):
ns = {}
ns.update(kwargs)
ns[args] = args
ns[retval] = None
exec self.code in ns
try:
func = ns[std_func_name]
except KeyError:
return ns[retval]
else:
# Already passed kwargs into the namespace
return func()
Then, a code object can either return a value by using whatever happens
to be in 'retval' when it's done executing, or by defining a
'std_func_name' function and using its return value.
So the interface for these Codenodes needs to be able to accept
arguments as a name/value dictionary corresponding to the elements in
the HTML form (the 'args' argument in my example above). This dictionary
is passed on to the code object. The kwargs are a few important
variables (not supplied by the form) that all Codenodes need to know,
such as the current user and maybe a database cursor.
Each Codenode knows how to deal with the input from its associated form.
(Or forms! There is, for example, a generalized commit Codenode that
knows how to update the state of *any* node if a form follows a certain
template.) When it is done, it needs to then return whichever node
should be displayed next. If the operation being attempted violates the
user's permissions, it might return the access denied node. (Actually,
in that case it will raise an AccessDenied exception and expect
something down the line to deal with it, so I can define what the
access denied node is in a central place, but you get the idea.) If
the operation resulted in a new node being created, it might return the
new node. c.
Sorry if I tend to ramble, heh. :-)
-Kirk McDonald
--
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Re: Fast generation of permutations
Paul Rubin wrote: def deals(): for i in xrange(13**5): cards = [(i//p) % 13 for p in (1, 13, 169, 2197, 28561)] yield cards This gives hands like [0,0,0,0,1] and [0,0,0,1,0] which are permutations of one another. Below is a piece of code that avoids this. Here's how to interprete its output. Suppose one gets a hand like [0,1,2,3,4]. This means that it would be possible to create 1024 (4**5) poker hands from this, by coloring the cards. Another hand, for example [0,0,1,2,3], would allow only 384 colorings, because the two zeros would contribute choose 2 out of 4 (colors), so 6 colorings. The other numbers remain available for 4 colorings, which gives 6*4**3 (==384) colorings for this hand. Similar things happen for other partionings of the hands into numbers. In fact I am now investigating a description based on integer partitions of the number 5. I am not sure whether I want to partition based on colors or on numbers, that seems to arbitrary. This is very fascinating. Maybe someday I'll make a tkinter script with a visual tree structure allowing all kinds of numbers of cards, and arbitrary numbers of variables to partition by. This would then give result sets like those strange quantum particles, such as quarks. Have fun, Anton def hands(L = [0]): if len(L) == 6: if L[1] != L[-1]: #no five of a kind yield L[1:] else: for i in range(L[-1],13): for H in hands(L+[i]): yield H def pprint(i,hand): print '%5i: ' %i, for x in hand: print '%2i ' % x, print def test(): H = hands() total = 0 for i,x in enumerate(H): pprint(i,x) if __name__=='__main__': test() -- http://mail.python.org/mailman/listinfo/python-list
Re: writing large files quickly
Donn wrote: How the heck does that make a 400 MB file that fast? It literally takes a second or two while every other solution takes at least 2 - 5 minutes. Awesome... thanks for the tip!!! Because it isn't really writing the zeros. You can make these files all day long and not run out of disk space, because this kind of file doesn't take very many blocks. The blocks that were never written are virtual blocks, inasmuch as read() at that location will cause the filesystem to return a block of NULs. Under which operating system/file system? As far as I know this should be file system dependent at least under Linux, as the calls to open and seek are served by the file system driver. Jens -- http://mail.python.org/mailman/listinfo/python-list
Re: Intro to Pyparsing Article at ONLamp
Paul McGuire wrote: I just published my first article on ONLamp, a beginner's walkthrough for pyparsing. Please check it out at http://www.onlamp.com/pub/a/python/2006/01/26/pyparsing.html, and be sure to post any questions or comments. I like your article and pyparsing. But since you ask for comments I'll give some. For unchanging datafile formats pyparsing seems to be OK. But for highly volatile data like videotext pages or maybe some html tables one often has the experience of failure after investing some time in writing a grammar because the dataformats seem to change between the times one uses the script. For example, I had this experience when parsing chess games from videotext pages I grab from my videotext enabled TV capture card. Maybe once or twice in a year there's a chess page with games on videotext, but videotext chess display format always changes slightly in the meantime so I have to adapt my script. For such things I've switched back to 'hand' coding because it seems to be more flexible. (Or use a live internet connection to view the game instead of parsing videotext, but that's a lot less fun, and I don't have internet in some places.) What I would like to see, in order to improve on this situation is a graphical (tkinter) editor-highlighter in which it would be possible to select blocks of text from an (example) page and 'name' this block of text and select a grammar which it complies with, in order to assign a role to it later. That would be the perfect companion to pyparsing. At the moment I don't even know if such a thing would be feasible, or how hard it would be to make it, but I remember having seen data analyzing tools based on fixed column width data files, which is of course in a whole other league of difficulty of programming, but at least it gives some encouragement to the idea that it would be possible. Thank you for your ONLamp article and for making pyparsing available. I had some fun experimenting with it and it gave me some insights in parsing grammars. Anton -- http://mail.python.org/mailman/listinfo/python-list
Re: writing large files quickly
Ivan wrote: Steven D'Aprano wrote: Isn't this a file system specific solution though? Won't your file system need to have support for sparse files, or else it won't work? Yes, but AFAIK the only modern (meaning: in wide use today) file system that doesn't have this support is FAT/FAT32. I don't think ext2fs does this either. At least the du and df commands tell something different. Actually I'm not sure what this optimisation should give you anyway. The only circumstance under which files with only zeroes are meaningful is testing, and that's exactly when you don't want that optimisation. On compressing filesystems such as ntfs you will get this behaviour as a special case of compression and compression makes more sense. Jens -- http://mail.python.org/mailman/listinfo/python-list
Re: writing large files quickly
Donn wrote: Because it isn't really writing the zeros. You can make these files all day long and not run out of disk space, because this kind of file doesn't take very many blocks. The blocks that were never written are virtual blocks, inasmuch as read() at that location will cause the filesystem to return a block of NULs. Are you sure that's not just a case of asynchronous writing that can be done in a particularly efficient way? df quite clearly tells me that I'm running out of disk space on my ext2fs linux when I dump it full of zeroes. Jens -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs C for a mail server
If your friend is proficient in C/C++ then learning Python should not be a pain. Quite the contrary, it should be an enlightnement. Being good in C/C++ AND Python is a killer combination, as you can promptly and efficiently code big chunks of your application in Python and interface with C/C++ code where (and if) high performance is required. Now, you should definitely check the requirements for the homework. If the assignment is about being able to decipher an RFC and implement it correctly with a nice software design, then I would definitely opt for Python. Having to squish memory management, string manipulation and character encoding bugs in C/C++ is not fun and not related to high-level design nor RFC support. If it's just a way to throw a programming challenge at your friend's face, then you should check whether it's okay to use Python rather than C/C++, otherwise he could be charged of cheating by using a more productive language :). Regards, Nicolas -- http://mail.python.org/mailman/listinfo/python-list
Re: beta.python.org content
Steve Holden wrote: How does http://beta.python.org/about/beginners/ look? regards Steve Hi, I'm an actualy Python beginner, decided recently to play with Python. I'm a user, not a professional programmer or developer of any sort, so I guess the beginner's page would be aimed at folks like me. It looks fine, degrades pretty well in Dillo. But.it needs more Beginners links and info. The Why Python seems a bit out of place, more akin to something that would be on the beta home, which looks a little corporate brochure site to me. It also seems a little bland as a beginner site goes. A little bit of fun and friendliness in the spirit of Python for Everyone might be something to add. That's what brought me to Python. The idea that Python was not just for people like ESR who've been programmers for decades, or for corporate types designing applications containing a new paradigm of competencies in objective oriented programming, but for high school students, hobbyist programmers and even those who've never written a line of code in their lives. It has been suggested that a Google-like hierarchy might be useful and I agree, though I don't know how that might work in practice. You could have a bland brochure site with the proper buzzwords for the corporates, another for the devs with late breaking patches, news, RSS feeds, whatever they need. and one for Education and/or beginners, with perhaps a colorful friendly look. (but perhaps keeping the same basic overall base look) I actually like the look of the current http://www.python.org It packs a lot of useful links in one page and it seems friendly Which probably sounds silly to describe an emotional reaction or feel to a site. Admittedly it doesn't look corporate or slick professional but that's not necessarily a bad thing. I agree with others about the new logo. It lacks a certain, pardon the expression, je ne sais quoi. (one of the things that got me interested in Linux was seeing that penguin associated with the word Linux and making me curious about what that Linux thing was all about) But it would make a good logo for a enterprise.python.org business.python.org So perhaps different logos for different purposes? A cartoony friendly python in front of a blackboard for education (similar to the Pygame python) A python reading a book at the base of a larch for a listing of books That sort of thing. The python.org site's been useful to me, pointing me to interesting software, documentation and whatnot. Though I didn't know about IDLE until I saw it mentioned in a post on Slashdot in a story asking for recommendations for Python IDE's. I am very new to Python. CronoCloud (Ron Rogers Jr.) -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I dynamically create functions without lambda?
On Sat, 28 Jan 2006 00:13:28 -0800, Kay Schluehr wrote: [snip lambda calculus stuff] In Python you can write: Y = lambda g: (lambda f: g(lambda arg: f(f)(arg))) (lambda f: g(lambda arg: f(f)(arg))) This serves the purpose. Try Y(F) and see. Is any of this stuff maintainable in the real world of IT, where most programmers don't have computer science degrees? You come along six months after the project was finished to maintain this code and discover that the whiz-kid lambda calculus guy never commented anything because that would detract from the elegance of his one liners; what happens next? -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
File date attribute
Hi: am a Newbie and this is my first script: We were recently burgled and had our computers stolen. Easy to replace, but the data that was lost is years and years of work. I've investigated offsite data backup but it seems expensive. In any case, the data we have is not volumous. Rather, would like to send emails of files to a backup address at gmail. So, this is my plan: Run a script in cron.daily. The script should check a timestamp placed by the last occurrence of that script. Then check my home folder for files modified between that timestamp and now. Then send those files off to gmail. I have most of the pieces in place, except I can't find out how to retrieve the date modified attribute of a file. Does anybody know how to do that? I'll post the full script when I'm done in case there is anybody who would like to use it. Kindest, BG -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs C for a mail server
Nicolas wrote: If it's just a way to throw a programming challenge at your friend's face, then you should check whether it's okay to use Python rather than C/C++, otherwise he could be charged of cheating by using a more productive language :). Though this comment of mine is likely to start a religious war, it might also bring up some useful points. I'm a bit relucted to swallow the common view of Python being a so- productive language, especially compared to C++. I value C++ productiveness actually much higher than it's performance. To stick to the mailserver example, I'm pretty sure I'd do it in C++. I got very exited about Python when I first saw it, but I've encountered several problems that hindered productivity dramatically. One thing is the lack of static types. The problem is not only that the compiler can't tell you very basic things you're doing wrong but also that code isn't intrinsically documented: def send_mail(mail): ... What can I do with mail? In C++, you're looking up what type it is (presumably by pressing M-x in Emacs on the word before it) and have a look on it's type definition. In Python, it can be quite difficult to tell what you can do with it because the information of what will be passed in can be several layers up. Also there is not even symbol-safety: self.not_defined will never rise a compile-time error. And to address the memory management critisism about C++: Unless you have cyclic structures (you probably won't have in a mail server), just use smart pointers and you don't have to be concerned more about it than you'd have to be in Python. I aggree on C++ libraries being weak on unicode strings though, or even generally weak in the libraries (you have the C libraries, but they're not very type safe or elegant to use). I'm aware that C++ is a horrible monstrosity, an argument whiches weight depends on the OP's friends C++ experience. Please don't be offended, but if anyone could make a point of how Python's disadvantages in these regards could be alleviated, I'd be very interested. Jens -- http://mail.python.org/mailman/listinfo/python-list
Re: File date attribute
Bruce R Graham enlightened us with: Run a script in cron.daily. The script should check a timestamp placed by the last occurrence of that script. Then check my home folder for files modified between that timestamp and now. Then send those files off to gmail. I have most of the pieces in place, except I can't find out how to retrieve the date modified attribute of a file. Does anybody know how to do that? man find. You can even tell it to list all files older than a reference file. Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs C for a mail server
Jim Segrave enlightened us with: Any lecturer assigning write a mail server as a class project is doing his/her students a true dis-service. At one time, I got an assignment Write a robust, user friendly SMTP client. That was just after we learned how to user 'for' loops and 'if' statements. Talk about dis-services ;-) Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
Re: beta.python.org content
I'd like to see the use of Python grow as dramatically as it deserves to. As I see it, there are at least three major categories of web visitors that we need to cater to: - Existing python users - Potential python users - Managers The current site's front page seems to be aimed mainly at existing python developers. I agree with Magnus about not specifying who should be interested in a particular page. The most effective web marketing of an Open Source development tool recently has probably been http://www.rubyonrails.org/. I think the link on the front page to a very slick coding video demonstration helped a lot there. Do we have anything like that for Python yet? TurboGears (http://www.turbogears.org/index.html) seems to have captured the same spirit of exciting marketing hype. They are both very cool tools as well, but so is Python. Can we adapt any of the techniques they use for the Python website? Hope that helps, Bruce -- http://mail.python.org/mailman/listinfo/python-list
Re: Efficient Find and Replace
for i,v in enumerate(L):
if v == X:
L[i] = Y
Here's an alternate solution using a replacement dictionary:
M = {X:Y}
for i, v in enumerate(L):
L[i] = M.get(v, v)
[Fredrik Lundh]
but that's 2-3 times slower than the OP's corrected code for his use
case, so I'm not sure it qualifies as more efficient...
The alternate wasn't presented for efficiency. Its virtue is that with
no additional effort, it generalizes to substituting multiple
find/replace pairs in a single pass.
Raymond
--
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Re: How do I tell if I'm running in the PyWin interpreter?
Charles Krug [EMAIL PROTECTED] schrieb im Newsbeitrag news:[EMAIL PROTECTED] | On 2006-01-28, Steven D'Aprano [EMAIL PROTECTED] wrote: | | As the comment says, when I run this under Python Win, I get an (pretty | sure) Tkinter interface, not a command line, and I don't get my | EOFError when I expect to. | | When do you expect to get an EOFError? The only way I get an EOFError is | if I explicitly hit Ctrl-D while raw_input is running. When do you expect | to get it? Have you tried Ctrl-Z under Windows? | | | That's exactly how I use it everywhere else. Type until you're done | then hit Ctrl-D | | The problem is only when running under the PyWin IDE . . I'd been using | this for months under Idle and every place else I needed it. | | The problem is that PyWin doesn't give you a raw command line with in | response to raw_input, but gives you a text entry box and a nice | OK-Cancel yada yada interface that silently eats my EOF. | | I'd like to have a single tool I can use everywhere. So far as I can | tell, that means I have to detect the PyWin IDE and handle it | separately on initialization so I get a real raw input and not the | redefined Tkinter version. | import sys import os if os.path.basename(sys.executable) == 'Pythonwin.exe': #Pythonwin specific initialization else: #Other HTH, Vincent Wehren -- http://mail.python.org/mailman/listinfo/python-list
Re: Returning a value from code string
Kirk McDonald wrote: Another kind of node (I'm still deciding whether to call them Codenodes or Opcodes or maybe Pynodes) is a chunk of code that can be asked to run itself, and which can be edited, on the fly, from within the website. Thus, one can both alter the functionality of the site, and add functionality, from the site itself (so long as you have the user permissions to do so). As Steven said, U R pwn3d. 1f you d0n't sp3a| l33t (if you don't speak leet), that means you are screaming hack me, use me to launch attacks on other computers, and than attack my computer. Unless you have some revolutionary ideas in code-security analysis. In which case you can a lot more money than from implementing Everything2 in python. -Kirk McDonald --Max -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I dynamically create functions without lambda?
Steven D'Aprano wrote: On Sat, 28 Jan 2006 00:13:28 -0800, Kay Schluehr wrote: [snip lambda calculus stuff] In Python you can write: Y = lambda g: (lambda f: g(lambda arg: f(f)(arg))) (lambda f: g(lambda arg: f(f)(arg))) This serves the purpose. Try Y(F) and see. Is any of this stuff maintainable in the real world of IT, where most programmers don't have computer science degrees? Probably not. But the good thing about Y is that it is in closed form and the expression is not infinitely long. By the way I have no less a hard time to read C code with advanced data-structures and many type casts which is much more likely to happen in the real world. From what I've seen the only *practical* purpose fixpoint combinators serve is a kind of recursion overloading. Without modifying F one can memoize values by adapting the fixpoint combinator. We already know something similar from the Go4 command pattern but there is no self-referential entanglement and it is less general. You come along six months after the project was finished to maintain this code and discover that the whiz-kid lambda calculus guy never commented anything because that would detract from the elegance of his one liners; what happens next? Ask a Scheme guy at LtU. Accuse the original author in Den Haag and if caught put him to shame by making photos at a dentist. Google for lambda calculus Y. Ask someone here at comp.lang.python. Ask your boss for more time ;) Kay -- http://mail.python.org/mailman/listinfo/python-list
Re: writing large files quickly
Jens Theisen wrote:
Ivan wrote:
Yes, but AFAIK the only modern (meaning: in wide use today) file
system that doesn't have this support is FAT/FAT32.
I don't think ext2fs does this either. At least the du and df commands
tell something different.
ext2 is a reimplementation of BSD UFS, so it does. Here:
f = file('bigfile', 'w')
f.seek(1024*1024)
f.write('a')
$ l afile
-rw-r--r-- 1 ivoras wheel 1048577 Jan 28 14:57 afile
$ du afile
8 afile
Actually I'm not sure what this optimisation should give you anyway. The
only circumstance under which files with only zeroes are meaningful is
testing, and that's exactly when you don't want that optimisation.
I read somewhere that it has a use in database software, but the only
thing I can imagine for this is when using heap queues
(http://python.active-venture.com/lib/node162.html).
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SLUT distibution mangled?
Hi, I was trying to download and install the latest SLUT (0.9.0) from http://slut.sourceforge.net/download/index.html and it seems both the zip and the tar.gz files are corrupted - the directory aux and the files within can not be extracted (using windows BTW). This happened with both the zip _and_ the tar.gz file. The strange thing is: even when I'm trying to create a directory 'aux' by myself it is not possible! Anyone here ever encountered this problem? Thank you in advance, Ido Yehieli. -- http://mail.python.org/mailman/listinfo/python-list
Re: SLUT distibution mangled?
OKl, sorry this seems to have nothing to do with SLUT it self, for some reason a directory names 'aux' can not be created... most bizzare. mkdir aux just returns The directory name is invalid. -- http://mail.python.org/mailman/listinfo/python-list
Re: Using non-ascii symbols
Rocco Moretti wrote: Could it be APL? No, it was much newer... someone did it as a hobby language. -- http://mail.python.org/mailman/listinfo/python-list
Re: SLUT distibution mangled?
Ido Yehieli wrote: OKl, sorry this seems to have nothing to do with SLUT it self, for some reason a directory names 'aux' can not be created... most bizzare. mkdir aux just returns The directory name is invalid. on windows ? win32 reserves the file names CON, PRN, AUX, CLOCK$, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9 for devices. /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Python code written in 1998, how to improve/change it?
To provide some feedback I vould like to show the code which works fine
for me as a FSM machine. As speed is not the crucial issue for my
application, I have decided to use an approach showed in the Skip
Montanaro's code.
http://orca.mojam.com/~skip/python/fsm.py
(it is using dictionary to store state/transition dependencies).
Tanks to all for your previous postings.
Petr Jakes
State machine example, for the pull/push button mentioned earlier in
this discussion thread
class FSM:
'''the states dictionary contains user defined state/transition
table in the format:
{'start_state': {'event': {'guard': ('action', 'end_state')}},
according to the actual start_state, event and guard
combination,
the execute method reads the relevant action and end_state
from the states dictionary, then executes action and setup
end_state '''
def __init__(self):
self.states = {}
def add(self,start_state, event_trigger,event_guard,
action,newstate):
add a new state/transition information to the state
machine dictionary
if self.states.has_key(start_state)== False :
self.states[start_state]={}
if self.states[start_state].has_key(event_trigger)== False :
self.states[start_state][event_trigger]={}
if
self.states[start_state][event_trigger].has_key(event_guard)== False :
self.states[start_state][event_trigger][event_guard]={}
self.states[start_state][event_trigger][event_guard]=(action,
newstate)
def start(self, state):
set the start state
self.state = state
def execute(self, event,guard=None):
'''according to the actual start_state, event and guard
combination
read the relevant action and end_state from the
states dictionary,
then execute action and setup end_state '''
action, end_state = self.states[self.state][event][guard]
if action is not None:
apply(action, (self.state, event))
self.state = end_state
return
'''actions they has to be executed while the event occurs'''
def motor_off(state, input): print pushing the switch to the OFF
position
def motor_on(state, input): print lifting the switch to the ON
position
fsm = FSM()
'''we have to define state/transition table first,
wher state transitions are defined as:
('start_state', 'event', 'guard', 'action', 'end_state)'''
fsm.add(ON,lift,None,None,ON)
fsm.add(ON,push,None,motor_off,OFF)
fsm.add(OFF,push,None,None,OFF)
fsm.add(OFF,lift,None,motor_on,ON)
fsm.start(ON)
print start state is, fsm.state
events=(push,push,push,lift,lift,push,lift,push,lift,lift,lift,push,lift)
for event in (events):
fsm.execute(event)
print switch is , fsm.state
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textvariable help
I must be missing something basic.
Can anyone explain why 'A' does not show on the entry widget?
import Tkinter
root = Tkinter.Tk()
class Col:
Rows = [0]
def __init__(self):
Frame = Tkinter.Frame(root);
Frame.pack (side='left')
self.Rows[0] = Tkinter.StringVar();
Tkinter.Entry(Frame,textvariable=self.Rows[0]).pack ();
X = Col()
# X.Rows[0].set ('A') # 'A' displays in Entry this way
Y = Col()
X.Rows[0].set ('A') # Why not also this way?
Y.Rows[0].set ('B')
root.mainloop()
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Re: Python Drive Name is the search, what is the question?
On 1/28/06, Dennis Lee Bieber [EMAIL PROTECTED] wrote: However, you do have an entry that covers Python and Drive, with your URL at the bottom... Look Familiar??? -=-=-=-=-=-=- Gregory Piñero | 3 Dec 01:23 Picon Re: Detect Blank DVD or CD in CDROM Drive From: Gregory Piñero gregpinero at gmail.com Subject: Re: Detect Blank DVD or CD in CDROM Drive Newsgroups: gmane.comp.python.general Date: 2005-12-03 00:23:47 GMT That would be interesting if that's what they're looking for. I never did figure out how to do that. In fact, my post on using Python with NeroCmd.exe comes up first in a google search for python drivename no quotes. Here's the link if you're curious: http://www.answermysearches.com/index.php/nerocmdexe-and-python-automating-the-burning-process/10/ But I just don't think that's what they're looking for. I'll keep thinking about it. -Greg -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I tell if I'm running in the PyWin interpreter?
On 2006-01-28, Peter Otten [EMAIL PROTECTED] wrote: Charles Krug wrote: Is there a way to detect that I'm running the the PyWin interpreter so that I can bypass its raw_input behavior? You could test if pywin_specific_module in sys.modules: # use workaraound Or maybe you can get away with always using sys.stdin.readline() instead of raw_input()? Look into cmd.py for an example. Peter cmd.py is the battery included I was thinking of last night. Unfortunately it uses something that PyWin replaces. However I did note that PyWin's version raises KeyboardInterrupt out of its dialog box. That's not ideal, but at least it gives me an idea what I need to trap to exit. -- http://mail.python.org/mailman/listinfo/python-list
Re: writing large files quickly
Ivan wrote:
ext2 is a reimplementation of BSD UFS, so it does. Here:
f = file('bigfile', 'w')
f.seek(1024*1024)
f.write('a')
$ l afile
-rw-r--r-- 1 ivoras wheel 1048577 Jan 28 14:57 afile
$ du afile
8 afile
Interesting:
cp bigfile bigfile2
cat bigfile bigfile3
du bigfile*
8 bigfile2
1032bigfile3
So it's not consumings 0's. It's just doesn't store unwritten data. And I
can think of an application for that: An application might want to write
the biginning of a file at a later point, so this makes it more efficient.
I wonder how other file systems behave.
I read somewhere that it has a use in database software, but the only
thing I can imagine for this is when using heap queues
(http://python.active-venture.com/lib/node162.html).
That's an article about the heap efficient data structure. Was it your
intention to link this?
Jens
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Re: textvariable help
swisscheese wrote:
I must be missing something basic.
Can anyone explain why 'A' does not show on the entry widget?
import Tkinter
root = Tkinter.Tk()
class Col:
Rows = [0]
def __init__(self):
Frame = Tkinter.Frame(root);
Frame.pack (side='left')
self.Rows[0] = Tkinter.StringVar();
Tkinter.Entry(Frame,textvariable=self.Rows[0]).pack ();
X = Col()
# X.Rows[0].set ('A') # 'A' displays in Entry this way
Y = Col()
X.Rows[0].set ('A') # Why not also this way?
Y.Rows[0].set ('B')
root.mainloop()
Rows is a class variable, and since you're modifying it in place, Rows[0] will
always be set to the most recently created Entry widget.
what is it you're trying to do here ?
/F
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Re: Checking free disk space on Win32 ?
Hi !
Another method :
import os
print str(os.popen4('dir C:\ /AD |find octets|find
libre')[1].readlines()[0].split()[2])
Warning ! It's French version.
For english, perhaps (depend of DIR return format) :
import os
print str(os.popen4('dir C:\ /AD |find bytes|find
free')[1].readlines()[0].split()[2])
@-salutations
Michel Claveau
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General Type Checks (int, str, tuple, etc.)
Hello! So far, I am using something like »if isinstance(var, int):« to determine, whether var's value is an integer. Now I would like to know if there is any better possibility to do such general checks or may a construct with isinstance() even fail in certain cases? Cheers, Fabian -- http://mail.python.org/mailman/listinfo/python-list
Re: textvariable help
Thanks for the quick reply. With your reply and another tutorial I get it now. I needed self.Rows = ... in the constructor. I find myself wasting a lot of time with poor python docs. Whatever time Python is supposed to save I'm losing so far in looking up things. I suppose that will change as I get past the learning curve. Are you aware of any good docs on python that make it easy to find things? -- http://mail.python.org/mailman/listinfo/python-list
curses won't refresh screen
For some reason, I can't get curses to refresh the screen. Can someone offer a suggestion to try to debug this? Here is my python code snippet: stdscr=curses.initscr() curses.noecho() curses.cbreak() stdscr.keypad(1) global screen screen = stdscr.subwin(23, 79, 0, 0) screen.border() while 1 == 1: screen.addstr(5,5, str(time.localtime())) screen.refresh() When run this, the local time is displayed ONCE, and then never changes. Why isn't the screen.refresh() command refreshing the display? I'm running a terminal session from within KDE, but I didn't think this would matter. Any ideas to suggest? -- Casey Bralla Chief Nerd in Residence The NerdWorld Organisation http://www.NerdWorld.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Intro to Pyparsing Article at ONLamp
Anton Vredegoor [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] I like your article and pyparsing. But since you ask for comments I'll give some. For unchanging datafile formats pyparsing seems to be OK. But for highly volatile data like videotext pages or maybe some html tables one often has the experience of failure after investing some time in writing a grammar because the dataformats seem to change between the times one uses the script. There are two types of parsers: design-driven and data-driven. With design-driven parsing, you start with a BNF that defines your language or data format, and then construct the corresponding grammar parser. As the design evolves and expands (new features, keywords, additional options), the parser has to be adjusted to keep up. With data-driven parsing, you are starting with data to be parsed, and you have to discern the patterns that structure this data. Data-driven parsing usually shows this exact phenomenon that you describe, that new structures that were not seen or recognized before arrive in new data files, and the parser breaks. There are a number of steps you can take to make your parser less fragile in the face of uncertain data inputs: - using results names to access parsed tokens, instead of relying on simple position within an array of tokens - anticipating features that are not shown in the input data, but that are known to be supported (for example, the grammar expressions returned by pyparsing's makeHTMLTags method support arbitrary HTML attributes - this creates a more robust parser than simply coding a parser or regexp to match 'A HREF=' + quotedString) - accepting case-insensitive inputs - accepting whitespace between adjacent tokens, but not requiring it - pyparsing already does this for you For example, I had this experience when parsing chess games from videotext pages I grab from my videotext enabled TV capture card. Maybe once or twice in a year there's a chess page with games on videotext, but videotext chess display format always changes slightly in the meantime so I have to adapt my script. For such things I've switched back to 'hand' coding because it seems to be more flexible. Do these chess games display in PGN format (for instance, 15. Bg5 Rf8 16. a3 Bd5 17. Re1+ Nde5)? The examples directory that comes with pyparsing includes a PGN parser (submitted by Alberto Santini). What I would like to see, in order to improve on this situation is a graphical (tkinter) editor-highlighter in which it would be possible to select blocks of text from an (example) page and 'name' this block of text and select a grammar which it complies with, in order to assign a role to it later. That would be the perfect companion to pyparsing. At the moment I don't even know if such a thing would be feasible... There are some commercial parser generator products that work exactly this way, so I'm sure it's feasible. Yes, this would be a huge enabler for creating grammars. Thank you for your ONLamp article and for making pyparsing available. I had some fun experimenting with it and it gave me some insights in parsing grammars. Glad you enjoyed it, thanks for taking the time to reply! -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Match First Sequence in Regular Expression?
Alex Martelli wrote:
Christoph Conrad [EMAIL PROTECTED] wrote:
Hello Roger,
since the length of the first sequence of the letter 'a' is 2. Yours
accepts it, right?
Yes, i misunderstood your requirements. So it must be modified
essentially to that what Tim Chase wrote:
m = re.search('^[^a]*a{3}b', 'xyz123aabbaaab')
...but that rejects 'aazaaab' which should apparently be accepted.
... and that is OK. That was the request:
I'm looking for a regular expression that matches the first, and only
the first, sequence of the letter 'a', and only if the length of the
sequence is exactly 3.
--Armin
Alex
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MYSql, CGI web page search code not working
OK, I can now successfully enter data into my MySQL database through my CGI web page. I can click a button and retrieve all the records, but I can not seem to get the search code to work. Below is the web page code and then my Python script. When I click my search button it just gives me all the records I know this line is executing: cursor.execute(Select * from phone where name = name order by name) Because I played with the order by but it seems to ignore my where clause. No matter what I type in the form text box (or even if I leave it blank) I get all the records. I can hard code this line to: cursor.execute(Select * from phone where name = 'Fred' order by name) and it returns the one record corectly. Any ideas? Fred -- form action=cgi-bin/searchdata.py pEnter the name to find: pinput type=text name=name size=30 input type=submit value=Search /form -- #!/usr/local/bin/python print Content-Type: text/html\n import MySQLdb import cgi db=MySQLdb.connect(host = 'localhost', db = 'phone') cursor=db.cursor() cursor.execute(Select * from phone where name = name order by name) result = cursor.fetchall() for record in result: print 'p' print record[0] print '--' print record[1] print '--' print record[2] print '--' print record[3] print '/p' -- http://mail.python.org/mailman/listinfo/python-list
Re: Using non-ascii symbols
Runsun Pan [EMAIL PROTECTED] writes: Can you guys figure out the details ? Here is the decoded version: It looks that with all my 26 years I'm too old to understand something like that... All I can say is OMG... :-) IMO, a language is a living organism, it has its own life and often evolves with unexpected turns. Maybe in the future some of those Martian Words will become part of formal Taiwanese, who knows ? :) I am extremely against that for pt_BR (Brazilian Portuguese). There's a TV channel here that has some movies with net terms instead of pt_BR for the translation... -- Jorge Godoy [EMAIL PROTECTED] Quidquid latine dictum sit, altum sonatur. - Qualquer coisa dita em latim soa profundo. - Anything said in Latin sounds smart. -- http://mail.python.org/mailman/listinfo/python-list
Re: problems with documentation
BartlebyScrivener wrote: Specifically it's the TOPICS that I can't seem to get to work. The keywords and modules etc do work. But if I type, e.g., help(functions) it says, No documentation found If I type help(os) I get help on the os module. rpd The TOPICS seem to be case sensitve so help assertion would not work, but help ASSERTION will. Just figured this out myself, yesterday. CronoCloud (Ron Rogers Jr.) -- http://mail.python.org/mailman/listinfo/python-list
Re: textvariable help
swisscheese wrote: Thanks for the quick reply. With your reply and another tutorial I get it now. I needed self.Rows = ... in the constructor. I find myself wasting a lot of time with poor python docs. Whatever time Python is supposed to save I'm losing so far in looking up things. I suppose that will change as I get past the learning curve. Are you aware of any good docs on python that make it easy to find things? just curious, but what documentation told you to use a class variable in the way you did ? /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Fast generation of permutations
Anton Vredegoor [EMAIL PROTECTED] writes: def deals(): for i in xrange(13**5): cards = [(i//p) % 13 for p in (1, 13, 169, 2197, 28561)] yield cards This gives hands like [0,0,0,0,1] and [0,0,0,1,0] which are permutations of one another. Yes, that's intentional, I thought the idea was to figure out the probability of each type of poker hand, which means you have to count those multiple occurrences. Below is a piece of code that avoids this. Nice. Another hand, for example [0,0,1,2,3], would allow only 384 colorings,... Similar things happen for other partionings of the hands into numbers... This is very fascinating. Maybe someday I'll make a tkinter script with a visual tree structure allowing all kinds of numbers of cards, and arbitrary numbers of variables to partition by. Cool, I'd still like to know why (13**5)-13 = C(52,5) other than by just doing the arithmetic and comparing the results. Maybe your tkinter script can show that. -- http://mail.python.org/mailman/listinfo/python-list
Curses won't update screen - Solved!
My problem was caused by a getch() function which paused, waiting for the character. Live and learn. sigh For some reason, I can't get curses to refresh the screen. Can someone offer a suggestion to try to debug this? Here is my python code snippet: stdscr=curses.initscr() curses.noecho() curses.cbreak() stdscr.keypad(1) global screen screen = stdscr.subwin(23, 79, 0, 0) screen.border() while 1 == 1: screen.addstr(5,5, str(time.localtime())) screen.refresh() KeyPress = screen.getch() When run this, the local time is displayed ONCE, and then never changes. Why isn't the screen.refresh() command refreshing the display? I'm running a terminal session from within KDE, but I didn't think this would matter. Any ideas to suggest? -- Casey Bralla Chief Nerd in Residence The NerdWorld Organisation http://www.NerdWorld.org -- http://mail.python.org/mailman/listinfo/python-list
Re: VB to Python migration
see vb2py to help the conversion http://vb2py.sourceforge.net/ or if you want to convert vb6 to vb.net instead, there are tools from microsoft and others to help with that, such as: http://www.microsoft.com/downloads/details.aspx?FamilyId=10C491A2-FC67-4509-BC10-60C5C039A272displaylang=en or if you want to start over from scratch, the other recommendations are good, like pyqt and qt designer, or else do it as a web app instead of desktop app if it just involves basic form controls. -- http://mail.python.org/mailman/listinfo/python-list
Re: MYSql, CGI web page search code not working
db=MySQLdb.connect(host = 'localhost', db = 'phone') cursor=db.cursor() cursor.execute(Select * from phone where name = name order by name) You don't parametrize the query. The where-clause thus is a tautology, as the name is always the name. Do something like this: cursor.execute(Select * from phone where name = ? order by name, (name,)) Actually it might be necessary to use something different from the ? to specify the parameter - that depends on the paramstyle of your DB-Api. Check that in the interpreter with import MySQLdb print mySQLdb.paramstyle Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: textvariable help
None - it was a false impression I got somehow. -- http://mail.python.org/mailman/listinfo/python-list
Re: [IDE] - The Dynamic Opportunity - ActiveState Komodo IDE / Open Source
Ilias Lazaridis wrote: As a first step, a free personal edition (non-commercial and academic use) would help to spread the Komodo IDE within the communities. Yeah, and ActiveState makes up the loss in income on volume, eh? I've got no problem paying for good work. -- -Scott David Daniels [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: MYSql, CGI web page search code not working
print MySQLdb.paramstyle returns: format
I found one example like this:
cursor.execute('''Select * from phone where name=%s order by
name''',(name))
But I get this in my Apache error log:
NameError: name 'name' is not defined
Like my last problem I posted, I am sure it is something very simple
that I am missing!!
Fred
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Re: writing large files quickly
Jens Theisen wrote: Ivan wrote: I read somewhere that it has a use in database software, but the only thing I can imagine for this is when using heap queues (http://python.active-venture.com/lib/node162.html). I've used this feature eons ago where the file was essentially a single large address space (memory mapped array) that was expected to never fill all that full. I was tracking data from a year of (thousands? of) students seeing Drill-and-practice questions from a huge database of questions. The research criticism we got was that our analysis did not rule out any kid seeing the same question more than once, and getting practice that would improve performance w/o learning. I built a bit-filter and copied tapes dropping any repeats seen by students. We then just ran the same analysis we had on the raw data, and found no significant difference. The nice thing is that file size grew over time, so (for a while) I could run on the machine with other users. By the last block of tapes I was sitting alone in the machine room at 3:00 AM on Sat mornings afraid to so much as fire up an editor. -- -Scott David Daniels [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs C for a mail server
Jens Theisen [EMAIL PROTECTED] wrote:
...
Please don't be offended, but if anyone could make a point of how Python's
disadvantages in these regards could be alleviated, I'd be very
interested.
http://www.artima.com/weblogs/viewpost.jsp?thread=4639
http://www.mindview.net/WebLog/log-0025
Since Robert Martin and Bruce Eckel (the authors of the two documents
linked above) are both acknowledged gurus of statically typechecked
languages such as C++, the convergence of their thinking and experience
indicated by those documents is interesting.
Tools such as pychecker, pylint, etc, are also considered by some to be
a useful backstop, but unit-tests are the real answer.
The but without declaration it can't be self-documenting issue is a
red herring. Reading, e.g.:
int zappolop(int frep) { ...
gives me no _useful_ self-documenting information about the role and
meaning of frep, or zappolop's result. The code's author must obviously
add a little comment here to clarify -- and in that little comment,
adding the information about type, if at all relevant, is an obvious
task.
At Google, we collectively have rather a lot of experience in these
issues, since we use three general-purpose languages: Python, Java, C++.
In this mix, the role of C++ is essentially that of allowing the
programmer to have complete control on memory allocation issues: the
only widespread modern language to do that, since all others, including
both Java and Python, have garbage-collection. In the internal style
guide for C++, we forbid the use of so-called ``smart'' pointers which
would basically amount to a hacked-up garbage collection system (which
can never be as solid and thorough as those built into the virtual
machines used in Java or Python -- a GC system that's thread-safe is a
nightmare to build and debug based only on those smart pointers, for
example, and if you start locking and mutexing all over the place for
that purpose you'll soon see performance plummet...): if you want
garbage collection you use a garbage-collected language -- the choice of
C++ for a component implies that you need complete control of memory
issues for that component, therefore choosing C++ and ``too smart for
their own good'' pointers would be mutually contradictory. Our style
guides for all languages also impose using unit-tests, code reviews, and
standard formats for internal documentation, from naming of variables,
functions and classes to structure and form of comments. As a result,
quality and reliability are remarkably consistent and uniform.
We could say that Python is Google's secret weapon, except it's not so
very secret, since, in order to attract and hire Python experts, we do
of course need to let it be known that Python's important to us;-). In
a sense, I guess, we are fortunate that our competitors still appear not
to be fully aware of this -- it gives us a better chance to hire Python
luminaries and maintain a productivity edge;-).
Alex
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Re: Python vs C for a mail server
Jens Theisen wrote: Please don't be offended, but if anyone could make a point of how Python's disadvantages in these regards could be alleviated, I'd be very interested. Jens Well, I write Java, C++ and Python code, and I have posted a few thoughts about this on my blog : http://nicolas.lehuen.com/ My two latest problems with coding in C++ are due to the environments : libraries using different string types and the whole problem with the building system. I love the language, but I get a much better leverage through Python and Java due to the quality and ease of use of their built-in and third party libraries. I use C++ only for my core data structure (namely a tuned version of a ternary search tree which I use to build full text indices). Regards, Nicolas -- http://mail.python.org/mailman/listinfo/python-list
Re: Efficient Find and Replace
Murali wrote: Given: L = list of integers. X and Y are integers. Problem: find every occurrence of X and replace with Y Problem with both solutions is the efficiency. As everyone else says, you are hallucinating efficiency problems probably brought on by an overdose of Lisp or ML. Here is another way to get to what you want that will go even faster than the not-a-problem speed you have from simple compare and replace. lst = range(50) * 10 try: position = lst.index(X) while True: lst[position] = Y position = lst.index(X, position + 1) except ValueError: pass # finally could not find X I mention this only because people always seem to forget than index allows you to specify a start (and/or stop) position w/in the list. --Scott David Daniels [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: writing large files quickly
[Jens Theisen] ... Actually I'm not sure what this optimisation should give you anyway. The only circumstance under which files with only zeroes are meaningful is testing, and that's exactly when you don't want that optimisation. In most cases, a guarantee that reading uninitialized file data will return zeroes is a security promise, not an optimization. C doesn't require this behavior, but POSIX does. On FAT/FAT32, if you create a file, seek to a large offset, write a byte, then read the uninitialized data from offset 0 up to the byte just written, you get back whatever happened to be sitting on disk at the locations now reserved for the file. That can include passwords, other peoples' email, etc -- anything whatsoever that may have been written to disk at some time in the disk's history. Security weenies get upset at stuff like that ;-) -- http://mail.python.org/mailman/listinfo/python-list
Re: General Type Checks (int, str, tuple, etc.)
Fabian Steiner wrote: Hello! So far, I am using something like »if isinstance(var, int):« to determine, whether var's value is an integer. Now I would like to know if there is any better possibility to do such general checks or may a construct with isinstance() even fail in certain cases? The general rule is: don't check, let it fail if it wants to. If you are looking for an integral value check, you might prefer: isinstance(x, (int, long)) but again, think long and hard about your requirements. Embrace dynamic typing; don't try to write your old language in Python. --Scott David Daniels [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: writing large files quickly
Jens Theisen wrote: cp bigfile bigfile2 cat bigfile bigfile3 du bigfile* 8 bigfile2 1032bigfile3 So it's not consumings 0's. It's just doesn't store unwritten data. And I Very possibly cp understands sparse file and cat (doint what it's meant to do) doesn't :) I read somewhere that it has a use in database software, but the only thing I can imagine for this is when using heap queues (http://python.active-venture.com/lib/node162.html). That's an article about the heap efficient data structure. Was it your intention to link this? Yes. The idea is that in implementing such a structure, in which each level is 2^x (x=level of the structure, and it's depentent on the number of entries the structure must hold) wide, most of blocks could exist and never be written to (i.e. they'd be empty). Using sparse files would save space :) (It has nothing to do with python; I remembered the article so I linked to it; The sparse-file issue is useful only when implementing heaps directly on file or in mmaped file). -- http://mail.python.org/mailman/listinfo/python-list
Re: Efficient Find and Replace
Thanks for the replies. I always thought that Python lists were actually lists under the hood. If they are implemented as arrays of pointers things should be a lot more efficient. In particular what I thought was a Linear-time operation is actually an O(1) operation. Since python allows you to replace single items with lists e.g. L[x:x+1]= [a,b,c], It has to be a little more clever. But with good data structure design I beleive that this overhead can be amortized to O(1). The optional argument to lst.index also makes that an linear time code. Thanks for all the help. - Murali PS: Slowly python is becoming my more favourite language than even C (except in cases you just cannot use anything but C, e.g. writing a boot loader) -- http://mail.python.org/mailman/listinfo/python-list
Re: beta.python.org content
Terry Hancock wrote: On Fri, 27 Jan 2006 13:44:19 -0800 Scott David Daniels [EMAIL PROTECTED] wrote: Paragraph 3 in Why Python: and later in that paragraph, I'd change: ... extensions that provide compact numerical solutions to: ... extensions that provide compact high-speed numerical solutions And while we're at it, let's say Python is a language for programming high-speed, digital, electronic computers. Do you have any experience with high-speed, digital, electronic computers? The reason I included high-speed is that the paragraph is responding to its topic sentence: Some people (s)uppose because Python is an interpreted language that it is slow and unsuitable for scientific and engineering tasks. ... Python's easy extensibility has allowed ... extensions that provide compact numerical solutions. I am simply saying that compact numerical solutions doesn't really address the question of whether they are too slow. For those who are too young, or weren't film students, the answer is Yes, my aunt has one. Well, I am definitely not too young, but I was never a film student. What movie? --Scott David Daniels [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: We have zipimport, how about dllimport?
ctypes ? -- http://mail.python.org/mailman/listinfo/python-list
Re: MYSql, CGI web page search code not working
Fred wrote: No matter what I type in the form text box (or even if I leave it blank) I get all the records. Try this: #!/usr/local/bin/python print Content-Type: text/html\n import MySQLdb import cgi db=MySQLdb.connect(host = 'localhost', db = 'phone') cursor=db.cursor() cursor.execute(Select * from phone where name=%s order by name, (name,)) result = cursor.fetchall() for record in result: print 'p' print record[0] print '--' print record[1] print '--' print record[2] print '--' print record[3] print '/p' (Assuming the name of your text field is name.) -- http://mail.python.org/mailman/listinfo/python-list
Re: MYSql, CGI web page search code not working
Yeah, I already tried that (except you have a , after name. Your code produces the same error: NameError: name 'name' is not defined I know I am close!! Just missing some small thing... -- http://mail.python.org/mailman/listinfo/python-list
Re: MYSql, CGI web page search code not working
Fred wrote: Yeah, I already tried that (except you have a , after name. Your code produces the same error: NameError: name 'name' is not defined I know I am close!! Just missing some small thing... Oh, duh. I forgot something: #!/usr/local/bin/python print Content-Type: text/html\n import MySQLdb import cgi form = cgi.FieldStorage() db=MySQLdb.connect(host = 'localhost', db = 'phone') cursor=db.cursor() cursor.execute(Select * from phone where name=%s order by name, (form['name'].value,)) result = cursor.fetchall() for record in result: print 'p' print record[0] print '--' print record[1] print '--' print record[2] print '--' print record[3] print '/p' The comma is intentional: the MySQLdb wants the argument(s) as a tuple. -- http://mail.python.org/mailman/listinfo/python-list
Re: Returning a value from code string
Max wrote: Kirk McDonald wrote: Another kind of node (I'm still deciding whether to call them Codenodes or Opcodes or maybe Pynodes) is a chunk of code that can be asked to run itself, and which can be edited, on the fly, from within the website. Thus, one can both alter the functionality of the site, and add functionality, from the site itself (so long as you have the user permissions to do so). As Steven said, U R pwn3d. 1f you d0n't sp3a| l33t (if you don't speak leet), that means you are screaming hack me, use me to launch attacks on other computers, and than attack my computer. Unless you have some revolutionary ideas in code-security analysis. In which case you can a lot more money than from implementing Everything2 in python. --Max Heavens! Normal users can't edit code! They won't even see it! I'm not a *total* moron. The only thing users will be able to enter is some simplified HTML. This is a convenience feature for the (trusted) admins of the site. There are some simple permission features built into the API. Every database-altering API call takes the current user as an argument, and if they're not allowed, it tells them to get bent. Everything2 does this more or less the same way, and they've had few issues in the seven or so years they've been operating. -Kirk McDonald -- http://mail.python.org/mailman/listinfo/python-list
Re: writing large files quickly
On Fri, 27 Jan 2006 12:30:49 -0800, Donn Cave [EMAIL PROTECTED] wrote: In article [EMAIL PROTECTED], rbt [EMAIL PROTECTED] wrote: Won't work!? It's absolutely fabulous! I just need something big, quick and zeros work great. How the heck does that make a 400 MB file that fast? It literally takes a second or two while every other solution takes at least 2 - 5 minutes. Awesome... thanks for the tip!!! Because it isn't really writing the zeros. You can make these files all day long and not run out of disk space, because this kind of file doesn't take very many blocks. The blocks that were never written are virtual blocks, inasmuch as read() at that location will cause the filesystem to return a block of NULs. I wonder if it will also write virtual blocks when it gets real zero blocks to write from a user, or even with file system copy utils? Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
Re: MYSql, CGI web page search code not working
Thanks Kirk! That worked perfect! And makes perfect since now that I see it... Now that I have the main pieces working I can start expanding from here! Fred -- http://mail.python.org/mailman/listinfo/python-list
Calling DLL with several data fields in output params
Hi, I basically need to write a script that will make calls to a DLL and parse the return result for API calls that consist of several data fields in the input and output parameters. [Questions] [q1] Is ctypes the right Python library to use for this interaction. . . . . . I know about calldll but it seems quite poorly documented. [q2] Are there any existing windows DLLs that one could use to build simplified test code. . . . . . One that has several input and output parameters and playing with it will not kill my system. . . . . . Also, I'd rather not have to learn how to write a DLL to build a test case. BTY - I have not decided on the language yet but would love to do this in Python. Although, I am considering writing in C++ (me_b_newbie) -or- JNI (it_b_ugly) -or- Obj-C (it_b_cool). MS languages are not an option in my book :} Thanks, JsD -- http://mail.python.org/mailman/listinfo/python-list
Re: We have zipimport, how about dllimport?
[EMAIL PROTECTED] wrote: I may be on particularly potent crack, but I was wondering whether it would make sense to distribute python code in DLLs so that the memory occupied by the bytecode would be consumed only once even if there were multiple processes using the same bytecode. Or is there another way to accomplish code sharing? That wouldn't help much: as soon as a .pyc file is imported, it is passed to the marshal module, which will create a code object out of it (copying the actual data in the pyc file). Then, this code object gets executed, containing import, def, and other statements. The def statements, in turn, result in yet other code objects being created, copying fragments of the original code object. Then, the original code object is discarded (and its memory released). So typically, you have two levels of copying, each involving interaction with the per-process memory management. There is little hope for sharing here. Of course I don't need the functionality right this week, but capability of running shared code is one of the advantages of natively compiled languages and someone must already have thought of this and knows why it would never work. ;-) It's an advantage only if the code occupies a signifcant portion of the memory. In bytecode languages, byte code is much more compact than machine code, so there is comparatively little opportunity for savings. OTOH, in *JIT* languages, the JIT code again counts for something, and it typically has to be generated for each process. That's why Microsoft's .NET has ngen.exe, the ahead-of-time (traditional) compiler. The primary rationale is not sharing, though, but reducing the startup time. In .NET 2.0, there is even an OS service that creates compiled images of IL byte code. LISP and Smalltalk implementations have yet another approach: the image. They dump everything in memory into a disk file which can then be mapped into memory. This image is created after all the loading indirections and copies, and so constitutes the final form. So on the plus side, this allows for sharing of code across multiple instances of the same application. On the minus side, each Smalltalk application needs its own image (even if they share a lot of code). Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: MYSql, CGI web page search code not working
OK one more... how would I do a LIKE instead of a = in this code? cursor.execute(Select * from phone where name=%s order by name, (form['name'].value,)) Right off I think: cursor.execute(Select * from phone where name like %%s% order by name, (form['name'].value,)) But it blows up... -- http://mail.python.org/mailman/listinfo/python-list
Re: MYSql, CGI web page search code not working
Perfect again Kirk! Now I will study all this so I actually understand what is happening.. Thanks! Fred -- http://mail.python.org/mailman/listinfo/python-list
User login system
Can anyone recommend an open source user login system already written in Python that I could use with my site? Simplicity is the most important factor, but the ability to track users using cookies would be helpful. Hopefully somebody knows one? -- http://mail.python.org/mailman/listinfo/python-list
Re: User login system
sophie_newbie [EMAIL PROTECTED] writes: Can anyone recommend an open source user login system already written in Python that I could use with my site? Simplicity is the most important factor, but the ability to track users using cookies would be helpful. Hopefully somebody knows one? Take a look at TurboGears Identity module and at PEAK.security... -- Jorge Godoy [EMAIL PROTECTED] Quidquid latine dictum sit, altum sonatur. - Qualquer coisa dita em latim soa profundo. - Anything said in Latin sounds smart. -- http://mail.python.org/mailman/listinfo/python-list
Re: indentation messing up my tuple?
sorry i forgot to add in the code for my tuple which is at the very end tuple = (food+ drink + \n) data.append(tuple) f = open(froogle.sql, 'a') f.write ( ''.join( tuple ) -- http://mail.python.org/mailman/listinfo/python-list
Re: indentation messing up my tuple?
sorry i left out my tuple which is at the end of my code tuple = (food + drink + \n) data.append(tuple) f = open(froogle.sql, 'a') f.write ( ''.join( tuple ) -- http://mail.python.org/mailman/listinfo/python-list
Re: VB to Python migration
Josh schrieb: You haven't specified where your main pains are. Do you have at least rudimentary architecture ? How often do you have code reviews / refactored your code ? Have you been striving for good code ? Is it a total mess ? Guessing only from the number of screens, you probably have more than trivial amounts of data. *Based on that assumption*, I'ld move the data FIRST. Get rid of the JET engine! If you are certain you will have to support SQL server, make it SQL server and MSDE/new express version first. Only then (perhaps) think about adding a totally free database engine. If not, take your pick but *move the data*. While you are on it, refactor the old code into something at least resembling a 3 to 5 layered approach with COM. Doesn't need to be perfect 100%, but more than 50%. Then exchange the parts that benefit the most by implementation inheritance, since VB's interface inheritance is arguably the best technical reason for redundant code. I'ld guess the business layer[s] would be the next things to convert - but if your VB-forms are mostly slightly augmented copies differing only slightly, the GUI actually might benefit most from a rewrite, if the business rules are written redundance poor. One of the typical scenarios asking for GUI inheritance is insurance - customer data is only specific for few fields and even policy field groupings resemble each other across similar policies. A minmally redundant business layer could even in VB be implemented without too much sweat- for instance by having methods overwritten in a inheritance based OOP - design as name mangled methods on objects responsible across similar problem domains, keeping the common methods clean. Check your code with a critical eye - even code forced to be totally OOP for technical reason=langauge can be written across a wide spectrum of quality. If there is nothing which is good enogh to be converted last or no segregation/layering at all in the current program, (even if it came from the DOS dinosaurs, there were good coding practices known - some of the old libraries were better decoupled than modern day OOP class libraries.) get rid of most of the people responsible and start only then. my 0.02 EUR thomas We have a program written in VB6 (over 100,000 lines of code and 230 UI screens) that we want to get out of VB and into a better language. The program is over 10 years old and has already been ported from VB3 to VB6, a job which took over two years. We would like to port it to Python, but we need to continue to offer upgrades and fixes to the current VB6 version. Does anybody know of ways we could go about rewriting this, one screen at a time, in Python, and calling the screens from the existing program? We are also looking for a graphics toolkit to use. IronPython with it's .NET bindings and ability to integrate with Visual Studio looks good, but leaves that bad MS taste in the mouth. We currently use a MS Access back end and need to migrate to a proper SQL server. We need to leave options open for SQL Server (for customers who want to use existing infrastructure) and something like MySQL or PostgreSQL. But in the mean time, we need to be able to access an MSAccess (Jet) database from Python. Any answers/suggestions/pointers are greatly appreciated. Thanks, Josh Isted -- http://mail.python.org/mailman/listinfo/python-list
Re: Checking free disk space on Win32 ?
You might find the following interesting too http://unpythonic.net/jeff/tkdu/ Cheers, Davy Mitchell Mood News - BBC News Headlines Auto-Classified as Good, Bad or Neutral. http://www.latedecember.com/sites/moodnews/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python vs C for a mail server
On 2006-01-28, Steven D'Aprano [EMAIL PROTECTED] wrote: I am a novice in python.I have to implement a full fledged mail server Because that's just what the world needs, yet another mail server. :) C can be faster. And can be is the key. It's easy to write slow programs in C if you don't choose the right algorithms and architecture. which language will be easier? Python is easier to read, and write, and debug, and you will have fewer hard-to-debug memory issues. And you'll have fewer security issues with Python since you don't have to worry about buffer and stack exploits. -- Grant Edwards grante Yow! There's enough money at here to buy 5000 cans of visi.comNoodle-Roni! -- http://mail.python.org/mailman/listinfo/python-list
Re: textvariable help
swisscheese wrote: Thanks for the quick reply. With your reply and another tutorial I get it now. I needed self.Rows = ... in the constructor. I find myself wasting a lot of time with poor python docs. I have found the standard library documentation amazingly well written: http://www.python.org/doc/ Whatever time Python is supposed to save I'm losing so far in looking up things. I suppose that will change as I get past the learning curve. Python will save you a lot of time when you come back to your code 6 months later and when you begin to get some competence at the more esoteric aspects of python, like generators, closures, and magic methods. Are you aware of any good docs on python that make it easy to find things? It depends on your task. Jumping into GUI programming without a solid grasp of the language you are writing in can be frustrating. In fact jumping into GUI programming at all can be frustrating. I learnt from Learning Python by O'Reilly. Beyond that I highly recommend Python Programming. I especially recommend chapters 2, 3, 6, 7, and 8 of the latter. If you have the time, try to get through as much of both of those as you can. Beyond that, you may want to keep a copy of Python in a Nutshell by your keyboard. I use the classic Python Essential Reference, which is now pretty dated. If you have not worked through a tutorial on python basics, you should really stop what you are doing and spend a few hours doing that. It will make you much more pleased with the language. James -- http://mail.python.org/mailman/listinfo/python-list
String Manipulation Help!
OK, I'm stumped. I'm trying to find newline characters (\n, specifically) that are NOT in comments. So, for example (where - = a newline character): == 1: - 2: /*- 3: --- 4: comment- 5: --- 6: */- 7: - 8: CODE CODE CODE- 9: - == I want to return the newline characters at lines 1, 6, 7, 8, and 9 but NOT the others. I've tried using regular expressions but I dislike them because they aren't immediately readable (and also I don't bloody understand the things). I'm not opposed to using them, though, if they provide a solution to this problem! Thanks in advance for any suggestions anyone can provide. - Dave -- http://mail.python.org/mailman/listinfo/python-list
Re: MYSql, CGI web page search code not working
Dennis Lee Bieber wrote: On Sat, 28 Jan 2006 10:14:44 -0800, Kirk McDonald [EMAIL PROTECTED] declaimed the following in comp.lang.python: The comma is intentional: the MySQLdb wants the argument(s) as a tuple. The DB-API wants tuples... But my last perusal of the MySQLdb Python code showed that it would work with naked singletons... Ah! So it does. However, I still pass 'em as a tuple as a matter of course, since it's documented that way. *shrug* (Also, it saves that many keystrokes if I need to add arguments.) -Kirk McDonald -- http://mail.python.org/mailman/listinfo/python-list
Re: [IDE] - The Dynamic Opportunity - ActiveState Komodo IDE / Open Source
Scott David Daniels wrote: Ilias Lazaridis wrote: As a first step, a free personal edition (non-commercial and academic use) would help to spread the Komodo IDE within the communities. Yeah, and ActiveState makes up the loss in income on volume, eh? The personal edition costs currently $29,95. A $0,- personal edition would spread around quickly. Commercial users still have to order/upgrade the professional version ($295,-). I've got no problem paying for good work. This is not about paying for good work or not. It is about an opportunity for ActiveState and the dynamic language communities. - It is about a weaknesses-of [1] and upcoming/existent threats-for [2] the ActiveState Komodo IDE. After implementing the initial step (free personal edition), the situation would change slightly: *Strength*: free edition for non-commercial and educational use *available*. *Strength*: simplified distribution due to no-cost version (which could be packaged e.g. within distributions which have not strict open-source requirements. ActiveState would keep his rights). Those (and the other existent) strengths would not be enouth to deal with the threat [2]. Further steps would be necessary (like a step by step transformation to open source). The NetBeans IDE [end of 2004 - current status unknown] contained several non-open-source binaries, thus it was partial open source and not open source, as it was marketed. ActiveState could follow this example initially (whilst clarifying the status patial open source of course). Step by step, more and more binaries would be released into open source, allowing this way ActiveState to go slowly through the process of applying the necessary changes (including 'mentality'-change of the staff and the developers). The license could(!) be similar to the eclipse foundation's one. - Hope this has clarified the topic further. - - - both excerpts below are taken from: http://lazaridis.com/samples/com/ActiveState/product.html [1] *Weakness* * Komodo Free Edition Not Available o Could have e.g. negative influence on Open-Source-Communities o Reduces distribution *Suggestion* a) Initial Step: ActiveState should make the Komodo personal edition free of charge. *Commercial* users still need to upgrade to the *professional* version for a license fee. *Benefit* This would most possibly lead to *spreading* the IDE *widely* within the dynamic language communities and would attract users which look for a free IDE (which partially will update to the professional version). A free edition would *simplify* the *download* procedure drastically. A link get the free personal edition from the main page would be enough. No license-key required. Quick, Easy and no hassle - get an IDE for 5 dynamic languages. - [2] Threats eclipse dynamic language support - http://www.eclipse.org/proposals/dltk/ upcoming competitive IDE's (based on eclipse or others) . -- http://lazaridis.com -- http://mail.python.org/mailman/listinfo/python-list
Re: String Manipulation Help!
Dave wrote: OK, I'm stumped. I'm trying to find newline characters (\n, specifically) that are NOT in comments. So, for example (where - = a newline character): == 1: - 2: /*- 3: --- 4: comment- 5: --- 6: */- 7: - 8: CODE CODE CODE- 9: - == [snip] Well, I'm sure there is some regex that'll do it, but here's a stupid iterative solution: def newlines(s): nl = [] inComment = False for i in xrange(len(s)): if s[i:i+2] == '/*': inComment = True if s[i:i+2] == '*/': inComment = False if inComment: continue if s[i] == '\n': nl.append(i) return tuple(nl) Your example returns: (0, 64, 65, 80, 81) This probably isn't as fast as a regex, but at least it works. -Kirk McDonald -- http://mail.python.org/mailman/listinfo/python-list
Re: - The Dynamic Opportunity - ActiveState Komodo IDE / Open Source
*Weakness* * Komodo Free Edition Not Available o Could have e.g. negative influence on Open-Source-Communities o Reduces distribution You logic is badly flawed. -- http://mail.python.org/mailman/listinfo/python-list
Calling C++ function from python script
The module which i am creating is like Part A: 1. It does some processing by using python code. 2. The result of this python code execution is written to a text file. [This part is already compelete]] Part B: 1. I read a text file which is outputted by above python script in a C++ program 2. and again output of this c++ code is text file [This part is as well complete with graph data structure construction part involved, which i feel can be done in better way in C++ than in python] Now i want to integrate this flow. The communication between part A and part B is by call to a function present in C++ How should i do that? Kindly suggest some ways. Regards Pankaj -- http://mail.python.org/mailman/listinfo/python-list
Re: Checking free disk space on Win32 ?
Hi! Fun. Slow, but fun. Thanks. @-salutations Michel Claveau -- http://mail.python.org/mailman/listinfo/python-list
Re: String Manipulation Help!
This is great, thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: User login system
Jorge Godoy [EMAIL PROTECTED] wrote: sophie_newbie [EMAIL PROTECTED] writes: Can anyone recommend an open source user login system already written in Python that I could use with my site? Simplicity is the most important factor, but the ability to track users using cookies would be helpful. Hopefully somebody knows one? Take a look at TurboGears Identity module and at PEAK.security... Twisted's cred is another possibility. Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: - The Dynamic Opportunity - ActiveState Komodo IDE / Open Source
[EMAIL PROTECTED] wrote: *Weakness* * Komodo Free Edition Not Available o Could have e.g. negative influence on Open-Source-Communities My apologies for the inconvenience. The corrected sentence: Could have negative influence on image (e.g. within Open-Source-Communities ) http://lazaridis.com/samples/com/ActiveState/product.html o Reduces distribution You logic is badly flawed. My statements are normally backupd by rationales. You can simply verify their validity. - Reduces distribution I think no one can doubt that a free version (ideally one which can be redistributed freely) increases the distribution of a product. simplified distribution due to no-cost version (which could be packaged e.g. within distributions which have not strict open-source requirements. ActiveState would keep his rights). - The simplified download should be undoubtable, too: A free edition would simplify the download procedure drastically. A link get the free personal edition from the main page would be enough. No license-key required. Quick, Easy and no hassle - get an IDE for 5 dynamic languages. - Thank you for notifying me about the wrong wording. . -- http://lazaridis.com -- http://mail.python.org/mailman/listinfo/python-list
Re: String Manipulation Help!
Dave [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] OK, I'm stumped. I'm trying to find newline characters (\n, specifically) that are NOT in comments. So, for example (where - = a newline character): == 1: - 2: /*- 3: --- 4: comment- 5: --- 6: */- 7: - 8: CODE CODE CODE- 9: - == I want to return the newline characters at lines 1, 6, 7, 8, and 9 but NOT the others. Dave - Pyparsing has built-in support for detecting line breaks and comments, and the syntax is pretty simple, I think. Here's a pyparsing program that gives your desired results: === from pyparsing import lineEnd, cStyleComment, lineno testsource = /* -- comment -- */ CODE CODE CODE # define the expression you want to search for eol = lineEnd # specify that you don't want to match within C-style comments eol.ignore(cStyleComment.leaveWhitespace()) # loop through all the occurrences returned by scanString # and print the line number of that location within the original string for toks,startloc,endloc in eol.scanString(testsource): print lineno(startloc,data) === The expression you are searching for is pretty basic, just a plain end-of-line, or pyparsing's built-in expression, lineEnd. The curve you are throwing is that you *don't* want eol's inside of C-style comments. Pyparsing allows you to designate an ignore expression to skip undesirable content, and fortunately, ignoring comments happens so often during parsing, that pyparsing includes common comment expressions for C, C++, Java, Python, and HTML. Next, pyparsing's version of re.search is scanString. scanString returns a generator that gives the matching tokens, start location, and end location of every occurrence of the given parse expression, in your case, eol. Finally, in the body of our for loop, we use pyparsing's lineno function to give us the line number of a string location within the original string. About the only real wart on all this is that pyparsing implicitly skips over leading whitespace, even when looking for expressions to be ignored. In order not to lose eols that are just before a comment (like your line 1), we have to modify cStyleComment to leave leading whitespace. Download pyparsing at http://pyparsing.sourceforge.net. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Decoupling the version of the file from the name of the module.
I'm a newbie experimenting with Python. I want to incrementally develop a module called 'circle'. The problem is now that the file name is used for two purposes. To keep track of the version number and as the name for the module. So when I develop the first version of my file I have to call it circle_a.py. The name of the module then automatically becomes circle_a. But when I develop the next increment and call my file circle_b.py the module name changes as well. Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
[EMAIL PROTECTED] wrote: I'm a newbie experimenting with Python. I want to incrementally develop a module called 'circle'. The problem is now that the file name is used for two purposes. To keep track of the version number and as the name for the module. So when I develop the first version of my file I have to call it circle_a.py. The name of the module then automatically becomes circle_a. But when I develop the next increment and call my file circle_b.py the module name changes as well. Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. You have two choices: 1- Just get rid of the version number in the name (what's the point) and define a __version__ attribute in the module, that's what is usually done. 2- create a wrapper module called circle.py whose content will be something along the lines of from your_current_module_with_version import * I'd strongly suggest the first choice, there is no point in giving the version number into the file name of a module. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
[EMAIL PROTECTED] wrote: I'm a newbie experimenting with Python. I want to incrementally develop a module called 'circle'. The problem is now that the file name is used for two purposes. To keep track of the version number and as the name for the module. So when I develop the first version of my file I have to call it circle_a.py. The name of the module then automatically becomes circle_a. But when I develop the next increment and call my file circle_b.py the module name changes as well. Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. I would recommend just naming the file circle.py, and defining something like a variable named __version__ or maybe __revision__ at the top of the module. Then you can, I don't know, back up your old versions to other filenames or something. Or, if you really want to do this right, you could install Subversion. :-) -Kirk McDonald -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
[EMAIL PROTECTED] writes: Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. Really, you should use a source control system. That's a program that tracks the different versions of the files in your program. When one of your files reaches a state of stability, you check it in to a source repository which then remembers that version. You then go on editing the file in place. Later, you can restore the old version from the repository if you need to. Source control is the only sane way to do what you're trying to do. Messing around with renaming files to save old versions, as you're doing, only works for very small, short-lived projects. That scheme will drive you crazy in short order. SubVersion (http://subversion.tigris.org) is a popular source control system, maybe not the best, but compatible with some older widely used ones. I'd personally choose this one because I have some experience with it, but it's not ideal. Even if you don't choose to use it, you might read its online docs, to get a sense of what kinds of problems these programs try to solve. There's a newer one called Codeville, written in Python, that I haven't tried. There are numerous others I won't bother trying to list. Which one is best is the topic of religious wars, like the best editor or the best language. Just pick one that you like and stick with it. -- http://mail.python.org/mailman/listinfo/python-list
Re: SLUT distibution mangled?
So I can't run SLUT on windows then? -- http://mail.python.org/mailman/listinfo/python-list
Python loading library containing embedded python...
I have a dll/so which embeds python. I can verify it works by compiling it as an executable and adding an appropriate main. I tried to write unit tests for this library with ctypes and a simple python script. Access violations and other strange things result. I suspect this is because I am basically embedding python in python at this point. How can I make my dll/so with embedded python support use via ctypes? If Py_NewInterpreter is the answer, why does it hang indefinitely? The dll/so must support use in processes which might contain other instances of Python. I can not change that requirement. Running via ctypes is an easy test of this capability (or much of it I suspect). -- http://mail.python.org/mailman/listinfo/python-list
