Re: python3: 'where' keyword
Nick Coghlan wrote: Andrey Tatarinov wrote: Hi. It would be great to be able to reverse usage/definition parts in haskell-way with where keyword. Since Python 3 would miss lambda, that would be extremly useful for creating readable sources. Usage could be something like: res = [ f(i) for i in objects ] where: def f(x): #do something [snip] For compound statements, a where clause probably isn't appropriate, as it would be rather unclear what the where clause applied to. Right. But you know that as soon as you add this to simple expressions, a bunch of people are going to come here whining about how they don't get to use where with if-expressions. Frankly, they might have a point here. Although we have replacing lambda expressions on our minds, I have in mind a different problem that a where-statement would solve perfectly. But it would have to be used with an if-expression. However, I think it might not be so hard. Let's take Paul Rubin's advice and precede the if statement with where. Let's also allow elif clauses to be replaced with else where ... if clauses. That which is bound in the while-block would be visible in both the if-expression and if-block. Then we could do this: . where: . m = someregexp.match(somestring) . if m: . blah blah blah . else where: . m = someotherregexp.match(somestring) . if m: . blah blah blah We might want to spell else where instead as elwhere, to match elif, but that's not important now. This would take away one of the major minor annoyances of Python. (In fact, I've suggested something like this as a solution to the set-and-test idiom, which Python makes difficult, only I used the keyword suppose instead of where.) Ok, but if you do that, now you have people whining that where comes after some expressions, and before others. (This would not bother me one bit, BTW, but I'm pretty sure I'd lose the popular vote on this one.) So, let's go all out and say that while could precede any statement. We now have consistency. Well, that really wouldn't work for the if-statement, though, because then how could we apply a different while-block to an else clause? We'd have to treat if-statements specially anyways. So we don't have consistency. My solution would be to propose two different where statements: a where...do statement, and a separate where...if statement. The where...do statement would look like this: . where: . def whatever(): pass . do: . blah blah use whatever blah It has the advantage of being able to apply the where bindings to several statements, and is, IMO, much cleaner looking than simply applying where's bindings to the single following unindented statement. I would recommend against where...while and where...for statements. They can't accomplish anything you couldn't do with a break statement inside the block, and it's not obvious whether the where clause gets executed once or for each loop (since it's physically outside the loop part). One question: what do you do with a variable bound inside a while-block that has the same name as a local variable? (Or, horrors, a surrounding while-block?) I'm inclined to think it should be illegal, but maybe it would be too restrictive. Anyways, I like this idea a lot. +1 -- CARL BANKS -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
snip So I've always had it in the back of my mind that languages that can easily support massive (especially automatic) parallelization will have their day in the sun, at least someday. and the language of the future will be called ... FORTRAN! :-) (joking, but it is the only language I know supporting massive parallelization ...) Michele Simionato -- http://mail.python.org/mailman/listinfo/python-list
Re: Software archeology (was Re: Developing Commercial Applications in Python)
In article [EMAIL PROTECTED], Stephen Waterbury [EMAIL PROTECTED] wrote: Aahz wrote: In article [EMAIL PROTECTED], Stephen Waterbury [EMAIL PROTECTED] wrote: Also see Python Success Stories: http://pythonology.org/success A notable example is Verity's search engine -- see http://python.oreilly.com/news/PythonSS.pdf Actually, your statement is slightly inaccurate. The Verity search engine is more than fifteen years old in its core technology; it was started as a LISP project at IIRC MIT. (At one point I was much amused to look at the C source code and find car() and cdr() functions.) As of my last information, Python isn't used at all in or with the Verity search engine. What you're referring to is the Verity Ultraseek engine, originally written and owned by Infoseek before getting transferred to Verity through a series of dot-bomb transactions. The Ultraseek engine doesn't use Python, but Python is used to control the engine, and I think much of the spider is written in Python. Actually, Aahz didn't add anything useful that wasn't explained better in the article itself, pointing to which was the purpose of my post, but he is correct: Python was *not* used to write the Verity search engine ... how the hell do these stupid rumors get started anyhow?? ;). Just read the article, dammit! :) You're quite correct that I added little useful information, but seeing as I used to work at Verity, I couldn't resist adding some hopefully interesting and/or amusing trivia. Especially the LISP bit. -- Aahz ([EMAIL PROTECTED]) * http://www.pythoncraft.com/ 19. A language that doesn't affect the way you think about programming, is not worth knowing. --Alan Perlis -- http://mail.python.org/mailman/listinfo/python-list
Re: Other notes
Bengt Richter wrote: IOW, I think there is a fix: keep tokenizing greedily and tokenize floating point as a sequence of integers and operators, and let integerdotinteger be translated by the compiler to floating point, and integerdotdotinteger be translated to the appropriate generator expression implementation. That would be: int-literaldotint-literal - float(int-literal + . + int-literal) int-literaldotidentifier - getattr(int(int-literal), identifier) int-literaldotdotint-literal - xrange(int-literal, int-literal) However, the problem comes when you realise that 1e3 is also a floating point literal, as is 1.1e3. Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
Getting List Of All Filesystem Mounts
Is there some pure Python/portable way to get a list of all currently mounted filesystems? Tim Daneliuk [EMAIL PROTECTED] PGP Key: http://www.tundraware.com/PGP/ -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: accessing the result of 'if'
Carl Banks wrote: Right. But you know that as soon as you add this to simple expressions, a bunch of people are going to come here whining about how they don't get to use where with if-expressions. Frankly, they might have a point here. Although we have replacing lambda expressions on our minds, I have in mind a different problem that a where-statement would solve perfectly. But it would have to be used with an if-expression. I have a different suggestion for this. 'as' is used for renaming in import statements. 'as' will be used for exception naming in Python 3k. So let's use it for expression naming in 'if' statements, too. if someregexp.match(s) as m: # blah using m elif someotherregexp.match(s) as m: # blah using m Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
Steve Horsley wrote:
But my understanding is that the current Python VM is single-threaded
internally,
so even if the program creates multiple threads, just one core will be
dividing
its time between those threads.
Not really.
The CPython interpreter does have a thing called the 'Global Interpreter Lock'
which synchronises access to the internals of the interpreter. If that wasn't
there, Python threads could corrupt the data structures. In order to do anything
useful, Python code must hold this lock, which leads to the frequent
misapprehension that Python is 'single-threaded'.
However, the threads created by the Python threading mechanism are real OS
threads, and the work load can be distributed between different cores.
In practice, this doesn't happen for a pure Python program, since any running
Python code must hold the interpreter lock. The Python threads end up getting
timesliced instead of running in parallel. Genuine concurrency with pure Python
requires running things in separate processes (to reliably get multiple
instances of the Python interpreter up and running).
Python threads are mainly intended to help deal with 'slow' I/O operations like
disk and network access - the C code that implements those operations *releases*
the GIL before making the slow call, allowing other Python threads to run while
waiting for the I/O call to complete. This behaviour means threading can give
*big* performance benefits on even single-CPU machines, and is likely to be the
biggest source of performance improvements from threading.
However, on multi-processor machines, it is also handy if a CPU-intensive
operation can be handled on one core, while another core keeps running Python code.
Again, this is handled by the relevant extension releasing the GIL before
performing its CPU-intensive operations and reacquiring the GIL when it is done.
So Python's concurrency is built in a couple of layers:
Python-level concurrency:
Multiple processes for true concurrency
Time-sliced concurrency within a process (based on the GIL)
C-level concurrency:
True concurrency if GIL is released when not needed
In some cases, problems with multi-threading are caused by invocation of
extensions which don't correctly release the GIL, effectively preventing *any*
other Python threads from running (since the executing extension never releases it).
As an example, I frequently use SWIG to access hardware API's from Python. My
standard 'exception translator' (which SWIG automatically places around every
call to the extension) now looks something like:
%exception {
Py_BEGIN_ALLOW_THREADS
try {
$action
} except (...) {
Py_BLOCK_THREADS
SWIG_exception(SWIG_RuntimeError, Unexpected exception)
}
Py_END_ALLOW_THREADS
}
The above means that every call into my extension releases the GIL
automatically, and reacquires it when returning to Python. I usually don't call
the Python C API from the extension, but if I did, I would need to reacquire the
GIL with PyGILState_Ensure() before doing so.
Without those threading API calls in place, operations which access the hardware
always block the entire program, even if the Python program is multi-threaded.
See here for some more info on Python's threading:
http://www.python.org/doc/2.4/api/threads.html
Cheers,
Nick.
--
Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia
---
http://boredomandlaziness.skystorm.net
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python Operating System???
But I thought Python was an all-purpose language. After all, OS's have been written in Lisp before too. It is a general purpose APPLICATION language. I am surprised that this hasn't been mentioned on this thread. An OS is NOT an application. It is a completely different kind of program. Do you guys understand the difference between user and kernel mode? Do you know what address spaces and hardware interrupts are? Python is not equipped to handle these things. You would end up doing so much in C extensions that it could barely be called Python. I am not trying to be insulting... but unless someone would like to educate me otherwise, the idea of an OS written in Python is almost ludicrous. As I said, I think you might mean an OS SHELL, which would be a reasonable (although maybe unconventional) thing to write in python. Also I am no threading expert, but I would imagine it would be very hard to write a task scheduler in Python given that it has the whole GIL thing. (As I said that isn't my domain of expertise but I'm sure someone here could expound on that.) -- http://mail.python.org/mailman/listinfo/python-list
Re: Getting List Of All Filesystem Mounts
Tim Daneliuk wrote: Is there some pure Python/portable way to get a list of all currently mounted filesystems? Check out MtPython: http://bebop.bigasterisk.com/python/docs/MtPython -- Codito ergo sum Roel Schroeven -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Operating System???
Roose [EMAIL PROTECTED] writes: An OS is NOT an application. It is a completely different kind of program. Do you guys understand the difference between user and kernel mode? Do you know what address spaces and hardware interrupts are? Python is not equipped to handle these things. You would end up doing so much in C extensions that it could barely be called Python. You'd need some library functions to let Python access device registers and you'd need some low level code to dispatch interrupts into Python code. I am not trying to be insulting... but unless someone would like to educate me otherwise, the idea of an OS written in Python is almost ludicrous. Is an OS written in Lisp also ludicrous? Because it's been done. When Unix was first written, people thought implementing an OS in C was ludicrous. Everyone knew OS's had to be written in assembler. Also I am no threading expert, but I would imagine it would be very hard to write a task scheduler in Python given that it has the whole GIL thing. (As I said that isn't my domain of expertise but I'm sure someone here could expound on that.) The GIL is not part of the Python language. It's just an artifact of one particular implementation. -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: 'where' keyword
Nick Coghlan wrote: Killer app for this keyword: class C(object): x = property(get, set) where: def get(self): return Silly property def set(self, val): self.x = Told you it was silly Hey, this is super-elegant! AdSR -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: 'where' keyword
AdSR [EMAIL PROTECTED] writes: Killer app for this keyword: class C(object): x = property(get, set) where: def get(self): return Silly property def set(self, val): self.x = Told you it was silly Hey, this is super-elegant! Heh, even further: z = C() where: class C(object): ... Lets you make anonymous classes and singleton objects. -- http://mail.python.org/mailman/listinfo/python-list
Re: Getting rid of self.
BJörn Lindqvist [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] I think it would be cool if you could refer to instance variables without prefixing with self. Others have expressed such a wish -- this comes up perhaps once a year. The bottom line is that as long as Python has separate instance and local namespaces with possibly duplicate names, then there must be a way to tell which namespace a name should be looked up in. The current system is completely consistent with Python's object.attribute system. It would be odd if instance attributes were referred to differently in module level code and function level code. Terry J. Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Another look at language comparisons
Pierre Quentel wrote: http://khason.biz/blog/2004/12/why-microsoft-can-blow-off-with-c.html I almost didn't look at this, but I'm glad I did - quite a fun comparison, nicely arbitrary and reminds me of RFC in a similar vein :) Michael. -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: 'where' keyword
Bengt Richter wrote: It also allows the necessary but uninteresting setup for an expression to be moved out of the way, bringing the expression that does the real work to prominence. Killer app for this keyword: class C(object): x = property(get, set) where: def get(self): return Silly property def set(self, val): self.x = Told you it was silly Yes, that is cool and it _is_ an interesting idea. Are suites nestable? E.g., is this legal? ... And, is the whole thing after the '=' an expression? E.g., x = ( foo(x) where: x = math.pi/4.0 ) where: def foo(x): print 'just for illustration', x or is this legal? for y in ([foo(x) for x in bar] where: bar = xrange(5) ): baz(y) where: def baz(arg): return arg*2 Not trying to sabotage the idea, really, just looking for clarification ;-) yes, all your examples are correct. And that's the way I'd like to use this feature. -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: 'where' keyword
Nick Coghlan wrote: It also allows the necessary but uninteresting setup for an expression to be moved out of the way, bringing the expression that does the real work to prominence. Killer app for this keyword: class C(object): x = property(get, set) where: def get(self): return Silly property def set(self, val): self.x = Told you it was silly oh, that's great! I can't imagine prettier example -- http://mail.python.org/mailman/listinfo/python-list
Re: OT: google groups bug, or worse?
Bengt Richter wrote: What did you google with? Is this it? http://groups-beta.google.com/groups?hl=enie=UTF-8q=%22The+xsdbXML+framework+provides+a+flexible+and+well+defined+infrastructure%22qt_s=Search+Groups That was my *reply* to one of the original posts using Google, which I faked up when I couldn't find it (posted using google). The two originals aren't there. hmmm. -- Aaron Watters === You'd be paranoid too, if everyone was out to get you! -- http://mail.python.org/mailman/listinfo/python-list
tuples vs lists
I get what the difference is between a tuple and a list, but why would I ever care about the tuple's immuutability? Also, do you say 'too-ple' or 'chu-ple' - if you get my drift. (tomato or tomato kind of thing) TIA -- http://mail.python.org/mailman/listinfo/python-list
Re: Another look at language comparisons
[EMAIL PROTECTED] wrote: From the web site: Why Microsoft can Blow-Off with C#? These people have thought up programming languages Fortran, Prologue, Ada. The author is ignorant. Fortran was invented by IBM in the late 1950s, long before Microsoft existed. Ada was commissioned by the U.S. Department of Defense in the 1970s. The Prolog programming language is not spelled Prologue. I don't think that these people is refering to Microsoft. Instead, it is refering to the three pictures below the text. I assume they are the pictures of the respective authors of these languages. The bottom line of the article is that languages authored by men with beards are more successful than those authored by people without beards. At least the anecdotical evidence to that is overwhelming :-) And there is hope for Python, as Guido has recently been seen with a beard :-) http://www.tbray.org/ongoing/When/200x/2004/12/08/-big/IMG_3061.jpg Regards, Jan -- http://mail.python.org/mailman/listinfo/python-list
The best way to do web apps with Python?
What is the best way to web developemnt with Python? Is there anything close to PHP style in-page script placement that can create and use other Python objects? I am not really interested in Zope (I believe that is more a CMS than anything else?) I am also looking for something a little more structured than a series of CGI Scripts. While on the topic - what is the expectataion of Python for this kind of stuff? Would one use Python for certain other things but turn to PHP for web apps - or would one use their Python skills in place of PHP? TIA -- http://mail.python.org/mailman/listinfo/python-list
Re: Pre/Postconditions with decorators
Thank you very much. It is really a very elegant piece of code :-) Eiffel (language) has both type checking and design by contract. Python lacks both. Your module tackles type checking, I tried to execute arbitrary code before and after function execution to realize runtime assertions. I wonder if this should be separated in a Python checker-module. Both are part of the interface contract. Ciao -- http://mail.python.org/mailman/listinfo/python-list
Re: The best way to do web apps with Python?
worzel [EMAIL PROTECTED] writes: What is the best way to web developemnt with Python? Is there anything close to PHP style in-page script placement that can create and use other Python objects? I am not really interested in Zope (I believe that is more a CMS than anything else?) I am also looking for something a little more structured than a series of CGI Scripts. Basically, yes, there are various Python template systems similar to PHP. I won't name them because other people more knowledgeable than me will do a better job than I could. I'll say that Python is a better language than PHP, but getting a basic dynamic web app running in PHP is much simpler than it is in Python. Python's advantage starts to shine once the app gets complicated. While on the topic - what is the expectataion of Python for this kind of stuff? Would one use Python for certain other things but turn to PHP for web apps - or would one use their Python skills in place of PHP? TIA It's sort of a difficult trade-off and it depends a lot on your application, who will develop and maintain it, who will use it, where it will be deployed, etc. Lots more people know PHP than Python, PHP is easier to get started with, and cheap PHP hosting is available all over. So if you're building some simple app that you want to distribute widely and run everywhere, PHP is attractive. If you're building a complex system which you'll run on a server that you have more control over, and you'll have relatively high-powered developers on hand to maintain the code, Python beats PHP. -- http://mail.python.org/mailman/listinfo/python-list
Re: The limitation of the Photon Hypothesis
bill wrote: Please reply to [EMAIL PROTECTED], thank you ! No - I'll reply to the newsgroup, if you don't mind. The limitation of the Photon Hypothesis snip THE UNCERTAINTY PRINCIPLE IS UNTENABLE Big snip You cannot use classical theory to disprove quantum theory that easily. The uncertainty is quantum in origin, and not just an artifact of classical mechanics applied to clumsy measurement. You don't convince me. Also, I think you probably accidentally posted to the wrong newsgroup. Steve -- http://mail.python.org/mailman/listinfo/python-list
Re: tuples vs lists
worzel a écrit : I get what the difference is between a tuple and a list, but why would I ever care about the tuple's immuutability? Because, from a purely pratical POV, only an immutable object can be used as kay in a dict. So you can use tuples for 'composed key'. Bruno -- http://mail.python.org/mailman/listinfo/python-list
Re: Pre/Postconditions with decorators
Eiffel (language) has both type checking and design by contract. Python lacks both. Actually, Python is strongly typed. It's just dynamically instead of statically typed. Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
[http://www.gotw.ca/publications/concurrency-ddj.htm]. It argues that the continous CPU performance gain we've seen is finally over. And that future gain would primary be in the area of software concurrency taking advantage hyperthreading and multicore architectures. Well, yes. However, it's not as bad as it looks. I've spent a good part of my professional life with multiprocessors (IBM mainframes) and I have yet to write a multi-thread program for performance reasons. All of those systems ran multiple programs, not single programs that had to take advantage of the multiprocessor environment. Your typical desktop is no different. My current system has 42 processes running, and I'd be willing to bet that the vast majority of them aren't multi-threaded. Exactly. If every one of your processes had its own 2 Ghz processor running nothing else, I think you would be pretty happy. Your OS had better be well-written to deal with concurrent access to memory and disks, but I think for general application development there will be huge speed boosts with little need for new programming paradigms. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python/Qt Problem
On 2005-01-08, Michael [EMAIL PROTECTED] wrote: Hi, I am experiencing something very weird with PyQt. I have created several windows based on QWidget using Designer. I can easily hide and show these with the hide and show methods. However I have just created a new window with Designer and the show method works in my main script but not inside the button action method (not using proper temrinology, sorry) of another window. Why is that? This works fine for the other windows. If you do not get a satisfactory answer here, you should try the dedicated PyQt mailing list: http://mats.imk.fraunhofer.de/mailman/listinfo/pykde The other thing I would suggest is to post some code along with your description of what you believe it should do. I do not think anyone will be able to diagnose the problem without seeing the code. -- http://mail.python.org/mailman/listinfo/python-list
Re: tuples vs lists
worzel wrote: I get what the difference is between a tuple and a list, but why would I ever care about the tuple's immuutability? Mainly for security and speed. Many library functions return info by returning a reference to an internally held tuple, and could be damaged / compromised / corrupted if that internal data was modified by malicious code. If tuples were mutable (lists) then it would be necessary to return a copy instead. Also, do you say 'too-ple' or 'chu-ple' - if you get my drift. (tomato or tomato kind of thing) Try 'Two-pull'. Steve -- http://mail.python.org/mailman/listinfo/python-list
Re: why not datetime.strptime() ?
On 2005-01-07, Skip Montanaro [EMAIL PROTECTED] wrote: josh Shouldn't datetime have strptime? Sure, but it's not quite as trivial to implement as was strftime() support. While strftime() is a C library function and thus easily called from within the datetime C code, strptime() is implemented in Python as part of the time module for portability (strptime(3) is not universally available). You'd need to import the time module, call its strptime() function with the input string and format, then use the tuple it returns to initialize a new datetime object. Not sure this is exactly related, but I was using datetime the other day to make timestamps: import datetime ts = datetime.datetime.now().isoformat() ts '2005-01-08T09:45:16.896805' and figured there would be an easy way to reverse that. Something along the lines of: dt = datetime.datetime.fromisoformat(ts) -- http://mail.python.org/mailman/listinfo/python-list
Re: tuples vs lists
Cheers - thanks for the feedback guys - pretty much answers the question for me. 'Two-Pull' it is then, thanks. Steve Horsley [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] worzel wrote: I get what the difference is between a tuple and a list, but why would I ever care about the tuple's immuutability? Mainly for security and speed. Many library functions return info by returning a reference to an internally held tuple, and could be damaged / compromised / corrupted if that internal data was modified by malicious code. If tuples were mutable (lists) then it would be necessary to return a copy instead. Also, do you say 'too-ple' or 'chu-ple' - if you get my drift. (tomato or tomato kind of thing) Try 'Two-pull'. Steve -- http://mail.python.org/mailman/listinfo/python-list
Re: The best way to do web apps with Python?
Dnia Sat, 8 Jan 2005 21:11:49 +0800, worzel napisa(a): What is the best way to web developemnt with Python? Hmm. :) I prefer http://cherrypy.org + http://cheetahtemplate.org/. Very easy to learn and develop, yet powerfull. Is there anything close to PHP style in-page script placement that can create and use other Python objects? Check http://spyce.sourceforge.net or http://nick.borko.org/pse -- JZ ICQ: 6712522 http://zabiello.om -- http://mail.python.org/mailman/listinfo/python-list
Re: Other notes
Bengt Richter wrote: OTOH, there is precedent in e.g. fortran (IIRC) for named operators of the form .XX. -- e.g., .GE. for = so maybe there could be room for both. Yes, but in Fortran 90 ==, = etc. are equivalent to .EQ. and .GE.. It is also possible to define operators on native and user-defined types, so that Y = A .tx. B can be written instead of the expression with the F90 intrinsic functions Y = matmul(transpose(A),B) The Fortran 95 package Matran at http://www.cs.umd.edu/~stewart/matran/Matran.html uses this approach to simplify the interface of the Lapack library and provide syntax similar to that of Matlab and Octave. I don't know if the syntax of your idea clashes with Python, but it is viable in general. -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
On Sat, 08 Jan 2005 14:22:30 GMT, Lee Harr [EMAIL PROTECTED] wrote: [http://www.gotw.ca/publications/concurrency-ddj.htm]. It argues that the continous CPU performance gain we've seen is finally over. And that future gain would primary be in the area of software concurrency taking advantage hyperthreading and multicore architectures. Well, yes. However, it's not as bad as it looks. I've spent a good part of my professional life with multiprocessors (IBM mainframes) and I have yet to write a multi-thread program for performance reasons. All of those systems ran multiple programs, not single programs that had to take advantage of the multiprocessor environment. Your typical desktop is no different. My current system has 42 processes running, and I'd be willing to bet that the vast majority of them aren't multi-threaded. Exactly. If every one of your processes had its own 2 Ghz processor running nothing else, I think you would be pretty happy. Your OS had better be well-written to deal with concurrent access to memory and disks, but I think for general application development there will be huge speed boosts with little need for new programming paradigms. Not likely. How often do you run 4 processes that are all bottlenecked on CPU? It's not a common usage pattern. If you have 16 CPUs, and 15 of them are running mostly idle processes and that *one* process you'd wish would hurry the heck up and finish has the 16th pegged at 100% usage, you are not a happy camper. For the case where you do have a lot of competing unrelated processes, no doubt SMP is a big win automatically, but there will still need to be language innovations to make it easier to develop software which can benefit from the additional hardware for the more common case of individual CPU hungry processes. Jp -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
Jp How often do you run 4 processes that are all bottlenecked on CPU? In scientific computing I suspect this happens rather frequently. More is never enough. -- Bob Saltzman Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: 'where' keyword
At the risk of generating controversy, here's another type of example: def gcd(a, b): where: a: int, b: int return c where: c: int while a: a, b = b%a, a return b More can be found at http://aroberge.blogspot.com Andre -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
I remember a _few_ year ago when all specialists (Intel's) included agreed that the 100MHZ barrier would never be passed - so, at least, we did get free lunch for a couple of years :-) I also must add that in my 17 years of realtime/embedded programming, the problem usually was not the CPU speed - since you know _prior_ to the design of your software whether your CPU will change context on time when the hardware IRQ comes in - but rather the fact that all the software/peripherals had to share the same bus == that usually was where the bottleneck was. I guess my point is to not focus the performance of a system solely on its CPU's. Regards, Philippe -- *** Philippe C. Martin SnakeCard LLC www.snakecard.com *** -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
In article [EMAIL PROTECTED], [EMAIL PROTECTED] wrote: Michele deleted an attribution: snip So I've always had it in the back of my mind that languages that can easily support massive (especially automatic) parallelization will have their day in the sun, at least someday. and the language of the future will be called ... FORTRAN! :-) (joking, but it is the only language I know supporting massive parallelization ...) Less of a joke than you think, perhaps. Back in the early 1980s, a family friend said something like, In the year 2000, there will be a programming language. I don't know what it will look like, and I don't know what it will do. But I do know one thing: it will be called FORTRAN. After all, FORTRAN 2003 contains OOP support -- Aahz ([EMAIL PROTECTED]) * http://www.pythoncraft.com/ 19. A language that doesn't affect the way you think about programming, is not worth knowing. --Alan Perlis -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: 'where' keyword
Darn space-eater google groups :-( Here is it again, at teh risk of generating controversy .def gcd(a, b): .where: .a: int, b: int .return c where: .c: int .while a: .a, b = b%a, a .return b more examples can be found at aroberge.blogspot.com André -- http://mail.python.org/mailman/listinfo/python-list
Re: Returning same type as self for arithmetic in subclasses
Tim Peters wrote: Yes, and all builtin Python types work that way. For example, int.__add__ or float.__add__ applied to a subclass of int or float will return an int or float; similarly for a subclass of str. This was Guido's decision... I will not discuss it with him. He is usually right :-s Generally speaking, no. But I'm sure someone will torture you with a framework that purports to make it easy wink. Apparently not... But here is my solution. If anybody is interrested. It should also be obvious what I am working on. Btw. I really love doctests ... Unittests are a nice idea. But doctest is a really practical solution. ### class vDatetime(datetime): A subclass of datetime, that renders itself in the iCalendar datetime format. dt = vDatetime(1970, 1,1, 12, 30, 0) str(dt) '19700101T123000' dt2 = vDatetime(1970, 1,1, 0, 0, 0) str(dt - dt2) 'PT12H30M' Adding is not allowed dt + dt2 Traceback (most recent call last): ... AttributeError: 'NotImplementedType' object has no attribute 'days' def __init__(self, *args, **kwargs): datetime.__init__(self, *args, **kwargs) self.params = Params() def __add__(self, other): return self._to_vdatetime(datetime.__add__(self, other)) def __sub__(self, other): return self._to_vdatetime(datetime.__sub__(self, other)) def _to_vdatetime(self, result): if hasattr(result, 'timetuple'): return vDatetime(*result.timetuple()[:6]) return vDuration(result.days, result.seconds) def fromstring(st): Class method that parses try: timetuple = map(int, (( st[:4], # year st[4:6],# month st[6:8],# day st[9:11],# hour st[11:13],# minute st[13:15],# second ))) except: raise ValueError, 'Wrong format' return vDatetime(*timetuple) fromstring = staticmethod(fromstring) def __str__(self): return self.strftime(%Y%m%dT%H%M%S) -- hilsen/regards Max M, Denmark http://www.mxm.dk/ IT's Mad Science -- http://mail.python.org/mailman/listinfo/python-list
Re: Another look at language comparisons
Jan Dries wrote: [EMAIL PROTECTED] wrote: And there is hope for Python, as Guido has recently been seen with a beard :-) http://www.tbray.org/ongoing/When/200x/2004/12/08/-big/IMG_3061.jpg LOL, he is working on linux, isn't he? So it was about bloody time. -- hilsen/regards Max M, Denmark http://www.mxm.dk/ IT's Mad Science -- http://mail.python.org/mailman/listinfo/python-list
Re: The best way to do web apps with Python?
!DOCTYPE HTML PUBLIC -//W3C//DTD HTML 4.0 Transitional//EN HTMLHEAD META http-equiv=Content-Type content=text/html; charset=iso-8859-1 META content=MSHTML 6.00.2900.2523 name=GENERATOR STYLE/STYLE /HEAD BODY DIVFONT face=Arial size=2What is /FONTFONT face=Arial size Just FYI -- the post you posted was in HTML -- you might want to avoid this in the future. 99% of all posts to news groups are in text, not html. Html is hard for everyone to read with normal news readers and not usually of any extra value. It's also more of a security risk to read it -- because there is more potential for exploitation. Anyway, just thought I'd mention it if you didn't know. Take care, Rob -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Operating System???
So how would I make an OS Shell? -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter: passing parameters to menu commands
Philippe C. Martin wrote:
menu.add_cascade(label=File, menu=filemenu)
filemenu.add_command(label=New, command=lambda: callback('New'))
filemenu.add_command(label=Open..., command=lambda:
Of course you could do this with named forwarding functions if you
prefer
I'm not sure what 'named forwarding functions'
Bad choice of terminology, I just mean you can explicitly define
def handleNew:
callback('New')
etc.
are but I'm actually in a
class and when applying your suggestion in the following manner,
everything works (THANKS!)
def __Dec(self,p_string):
for i in p_string:
self.__Insert(i)
.
.
.
#menu creation
l_dec.add_command(label = 'ATR', command=lambda: self.__Dec('ATR'))
l_dec.add_command(label = 'IN', command=lambda:self.__Dec('IN'))
.
.
.
Yet I have a question:
If I replace the menu creation code as below, and since __Insert appends
the string p_string into a text widget that is created _after_ the menu
creation; the method __Dec seems to be called at the menu creation and
I get an error in __Insert because the test widget is equal to None.
My reflexes of C programmer tell me that command=self.__Dec just
passes a method pointer (sorry I said it) to add_command - yet it does
not seem to be so.
What is actually going on ?
#menu creation
l_dec.add_command(label = 'ATR', command=self.__Dec('ATR'))
l_dec.add_command(label = 'IN', command=self.__Dec('IN'))
self.__Dec is a reference to the function. It is similar to a method pointer so you don't need to
apologize ;) The name of a function without the () is a reference. When you append () it becomes a
call to the referenced function.
The command parameter for the menu must be a reference to a function. The function is called with no
arguments when the menu is invoked.
So, you need a function of no arguments to handle the command. For example,
def handleMenu():
print 'Handled'
filemenu.add_command(label=New, command=handleMenu)
Note there is no () after handleMenu. 'command' is bound to the function object; the function is not
called until later.
OK, now suppose you want to pass a parameter to handleMenu?
def handleMenu(menuName):
print 'Handled', menuName
Now what do you put in the command parameter? This won't work because you are *calling* handleMenu
and assigning the result of the call (in this case the value None) to 'command':
filemenu.add_command(label=New, command=handleMenu('New')) # WRONG
You need a new function of zero arguments to bind to 'command'. Here is one way
to do it:
def handleNew():
handleMenu('New')
filemenu.add_command(label=New, command=handleNew) # OK
Note, again, no () after handleNew. 'command' is bound to the function object
again.
OK, what about lambda? lambda is a way to create a simple anonymous function. One simple use of
lambda is to make a new function that binds a parameter to another function.
lambda: handleMenu('New')
defines a function that does the same thing as handleNew. The value of the lambda expression is the
function object. So
filemenu.add_command(label=New, command=lambda: handleMenu('New')) # OK
is another way to get the result you want.
Kent
--
http://mail.python.org/mailman/listinfo/python-list
there's a socket.sendall(), so why no socket.recvall()?
Subject says it all; there's a socket.sendall(), so why no socket.recvall()? I know that I can use the MSG_WAITALL flag with recv(), but this is not implemented on all platforms, most notably windows. --Iremn -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: 'where' keyword
When I first saw this I thought: hmmm... this seems as redundant as adding a repeat/until loop to Python; there's no chance in hell it will ever be accepted by the community or Guido, but I actually kinda like it. It's nice to see mostly positive reactions to this idea so far. I think it's a really ingenious solution to the the anonymous function problem - don't make it anonymous! A short, throwaway name with a very localized scope is as good as a truly anonymous function and feels more Pythonic to me. We thought we wanted a better syntax than lambda for anonymous functions but Andrey shows that perhaps it wasn't what we really need. What we need is a solution to quickly and cleanly generate bits of callable code without polluting the containing namespace, without having to think too hard about unique names and while making their temporary and local nature clear from the context. Anonymity isn't one of the requirements. I really liked Nick Coghlan's property example. The names 'get' and 'set' are too short and generic to be used without a proper scope but with this syntax they are just perfect. Here's another example: w = Widget(color=Red, onClick=onClick, onMouseOver=onMouseOver) where: . def onClick(event): do_this(event.x, event.y, foo) . def onMouseOver(event): someotherwidget.do_that() The onClick=onClick part seems a bit redundant, right? So how about this: w = Widget(**kw) where: . color = Red . def onClick(event): do_this(event.x, event.y, blabla) . def onMouseOver(event): someotherwidget.do_that() . x, y = 100, 200 . kw = locals() I'm not really sure myself how much I like this. It has a certain charm but also feels like abuse of the feature. Note that w = Widget(**locals()) where: would produce the wrong result as it will include all the values in the containing scope, not just those defined in the where block. Oren -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
Quoth Skip Montanaro [EMAIL PROTECTED]: | | Jp How often do you run 4 processes that are all bottlenecked on CPU? | | In scientific computing I suspect this happens rather frequently. I think he was trying to say more or less the same thing - responding to (IBM mainframes) ... All those systems ran multiple programs ... My current system has 42 processes running ..., his point was that however many processes on your desktop, on the rare occasion that your CPU is pegged, it will be 1 process. The process structure of a system workload doesn't make it naturally take advantage of SMP. So there will still need to be language innovations etc. -- to accommodate scientific computing or whatever. Your 4 processes are most likely not a natural architecture for the task at hand, but rather a complication introduced specifically to exploit SMP. Personally I wouldn't care to predict anything here. For all I know, someday we may decide that we need cooler and more efficient computers more than we need faster ones. Donn Cave, [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Installing IPython on win2k
Hi, I'm new to python, and ipython, but not to programming, having trouble getting ipython installed on windows 2000, python 233. Any help would be much appreciated; I'm sure I'm being some basic flavor of dense... First downloaded and installed PythonWin, readline and ctypes. They're all pretty clearly here and working, because I can run PythonWin, and from there, importing readline and ctypes works. Then downloaded ipython-0.6.6.zip and unzipped it. When I double-click setup.py, I get only a brief wait cursor; nothing else happens, and importing ipython as a test fails. I tried moving the whole unzipped dir to site-packages, no difference. Both files in the scripts dir, ipython and pycolor, have no filename extension, which seems odd to my newbie eye. I tried renaming them to .py, still no difference. My apologies for this basic question, and my no doubt ignorant flailing about. Very much looking forward to getting this working. Thanks, Dave Merrill -- http://mail.python.org/mailman/listinfo/python-list
Real Election Reform
What do you think about this and have you seen this popular site before? This was taken from a web site http://www.afvr.org How can we safeguard the integrity of each vote? Today we have technology that protects our financial systems, military weapon systems and national intelligent organizations. These proven systems can be combined in a way to issue serialized equipment to authorize personnel for the dates and hours needed. Each would have their own level of clearance to perform the tasks they are responsible for. Each action would be recorded and verified with a higher levels of network authority and again, only available during the hours and dates needed. Ballots would only be printed after the voter has cast their vote but before they leave the booth. If the voter made a mistake he could put the printed ballot into the booth's scanner for correction. All ballots scanned at the booth would go into a shredder and the voter could then correct his ballot on the screen and reprint his ballots. Once the voter accepts the printed ballot he submits his vote on the screen and takes the two ballots to the depository. So two computer generated, serialized and scanner perfect receipts of the completed ballot are printed.* One for the voter and one for the public record. This would eliminate all the extra ballots that could be used for unauthorized voting as well as any question of voter intent. Each piece of equipment involved in the issuing of the receipt would be linked to the serial# of that ballot and an electronic document would be generated that exactly matched the two printed receipts. So the voter themselves has validate the printed ballots, keeping one for themselves, while the other electronic time-stamped document is deposited into an optical scanner used as a secure depository. This second scanned count which should always match the electronic count. This paper ballot could also be used for recounts if needed. The voter could use the receipt to inquire about their vote in the future. The stuffing of the ballot box or finding ballots would be eliminated. With this system, if you find a ballot, you have to find the voter that cast that ballot too. This is not so in any of the current systems in place today nor have we ever heard such a system ever proposed. http://www.afvr.org -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
Donn Cave [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Quoth Skip Montanaro [EMAIL PROTECTED]: | | Jp How often do you run 4 processes that are all bottlenecked on CPU? | | In scientific computing I suspect this happens rather frequently. I think he was trying to say more or less the same thing - responding to (IBM mainframes) ... All those systems ran multiple programs ... My current system has 42 processes running ..., his point was that however many processes on your desktop, on the rare occasion that your CPU is pegged, it will be 1 process. The process structure of a system workload doesn't make it naturally take advantage of SMP. So there will still need to be language innovations etc. -- to accommodate scientific computing or whatever. Your 4 processes are most likely not a natural architecture for the task at hand, but rather a complication introduced specifically to exploit SMP. Exactly. I wasn't addressing some of the known areas where one can take advantage of multiple processors, or where one can take advantage of threading on a single processor to avoid delays. At this point in time, though, I see multithreading for compute intensive tasks to be an intermediate step. The final step is to restructure it so it can take advantage of cluster architectures. Then you can simply ignore all of the complexity of threads. That still leaves putting long running tasks (such as printing) into the background so the UI stays responsive. Personally I wouldn't care to predict anything here. For all I know, someday we may decide that we need cooler and more efficient computers more than we need faster ones. Chuckle. I basically think of shared memory multiprocessing as being perverse: the bottleneck is memory, not compute speed, so adding more processors accessing the same memory doesn't strike me as exactly sane. Nor does pushing compute speed up and up and up when it just stressed the memory bottleneck. Donn Cave, [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: OT: spacing of code in Google Groups
JanC wrote: Have a look at: http://gnuwin32.sourceforge.net/ They have native win32 builds of many of the GNU commandline utilities... Thanks, everyone, for all your kind help. (Uh, I thought it was clear I didn't actually *want* a method of cutting columns, since I have needed the functionality once in the last ten years, but on behalf of those who do what it and didn't know how to get it, I give you thanks. ;-) -quite-happy-with-simple-editors-and-a-command-line-ly y'rs, Peter -- http://mail.python.org/mailman/listinfo/python-list
windows mem leak
Does the Win32 port of Python have a memory leak? I have some code that runs flawlessly on Linux, but bombs after a few hours on Windows. It's threaded and uses a lot of memory. Thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: sorting on keys in a list of dicts
Nick Coghlan wrote: Stability in sorting is a property not to be sneezed at - it means switching to sorting by a second key gives the effect of sort by key 1, then by key 2, whereas that doesn't hold with an unstable sort Assuming key 1 refers to the first key, and key 2 to the second key, then I believe you meant gives the effect of 'sort by key 2 then by key 1'. In other words, if you have a stable sort algorithm and do one sort operation using key 2, then a second sort operation using key 1, it's the same as doing a single sort with the key combination key 1, key 2, not the other way around. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: 2 versions of python on 1 machine
flupke wrote: I used the 2 batch files technique and removed c:\python23 from my path var and all is fine now. Where did you find more info on PYTHONHOME and PYTHONPATH because the docs don't seem to contain a whole lot of info. Typing python -h gives a good start. I'm sorry, I don't recall where else there is useful info on those, though I'm pretty sure Google could help. (I'm not sure there's much to add to what the -h option tells you, however.) -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: 'where' keyword
Andrey Tatarinov wrote: print words[3], words[5] where: words = input.split() - defining variables in where block would restrict their visibility to one expression Then your example above doesn't work... print takes a sequence of expressions, not a tuple as you seem to think. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Operating System???
Paul Rubin wrote: When Unix was first written, people thought implementing an OS in C was ludicrous. Everyone knew OS's had to be written in assembler. Actually, when Unix was first written that belief was entirely correct, and OSes *did* have to be written in assembler. That is, pure C did not have the capability to handle all that was required. I recall it taking a good decade before it became *common* to find C compilers with, for example, @interrupt support to let the compiler generate code that properly saved all registers and used RTI instead of RTS (or whatever it might have been called one one's particular flavour of CPU). Now, once you added a few tiny interrupt handlers, and some context switching (stack manipulation) routines, pretty much everything else *could* be done in C, but that doesn't invalidate the point. I think it's safe to say that none of pure C, pure Lisp, or pure Python are really capable of being used as the *sole* language to build an operating system. It's also safe to say that this is a largely irrelevant point. It would probably only be of academic interest to try to do something like that. Any practical attempt would not think more than twice of resorting to a little glue in assembler or in the form of canned byte sequences built by hand and stuck into the appropriate places in memory... -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: OT: google groups bug, or worse?
[EMAIL PROTECTED] wrote: I'm concerned that google groups is not correctly reflecting the python lists. A month ago I announced the xsdbXML framework to the python list and the python-announce list. As you can see from the links below the python announce submission was approved by the moderators (thanks!) and the python list submission also went out, but the messages cannot be found at google groups. http://mail.python.org/pipermail/python-list/2004-December/254479.html http://mail.python.org/pipermail/python-announce-list/2004-December/003583.html Is it a google bug? Or is it something darker, like an anti-Python conspiracy at google? You didn't post via Google, right? Just sent to the mailing list? I believe that Google knows nothing about mailing lists, but watches a news feed, so if the list/Usenet gateway failed to deliver those messages, Google would never see them. Furthermore, news delivery is not necessarily guaranteed. (Actually, I don't recall how reliable the protocol is, but I doubt it's foolproof.) If any one of the news servers between yours and Google's happened to drop some messages, it's quite possible Google would never see them. Given the architecture of Usenet, I wouldn't be surprised if Google missed messages consistently, a very small percentage of the time. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
John Roth wrote: I have yet to write a multi-thread program for performance reasons. If we include in the set of things covered by the term performance not only throughput, but also latency, then I suspect you actually have written some multithreaded programs for performance reasons. *I* certainly have: that's easily the reason for threading in 95% of the cases I've dealt with, and I suspect those of many others. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Recent infoworld column
Dwarf Electrician wrote: from a long time listener... http://www.infoworld.com/article/04/12/30/01OPstrategic_1.html Kudos for Roger Binns! -- http://mail.python.org/mailman/listinfo/python-list
Re: windows mem leak
Bob Smith wrote: Does the Win32 port of Python have a memory leak? I have some code that runs flawlessly on Linux, but bombs after a few hours on Windows. It's threaded and uses a lot of memory. Let's see what you're missing: 1. platform specifics 2. versions of things involved 3. any sort of detail about the code 4. how you're noticing/measuring the problem 5. what bombs means 6. any mention that you've checked Sourceforge to see whether a similar problem has been reported There have been memory leaks in various past versions of Python, and could easily be in the current version, but they're generally rather specific in terms of the code that can trigger it. Once it was doing some particular work with a socket, once it was trying to append (or extend?) to an empty list, and so on. There are also a few ways you could have written your application to cause memory to leak as a result of your own code, not as a result of Python's. And it's even possible that this would happen only on one platform (though I'm trying hard to think of an example and can't... maybe it's very unlikely.) -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Operating System???
Peter Hansen wrote: Paul Rubin wrote: When Unix was first written, people thought implementing an OS in C was ludicrous. Everyone knew OS's had to be written in assembler. Actually, when Unix was first written that belief was entirely correct, and OSes *did* have to be written in assembler. *nods* That is, pure C did not have the capability to handle all that was required. I recall it taking a good decade before it became *common* to find C compilers with, for example, @interrupt support to let the compiler generate code that properly saved all registers and used RTI instead of RTS (or whatever it might have been called one one's particular flavour of CPU). If my memory serves me, you are entirely correct. Now, once you added a few tiny interrupt handlers, and some context switching (stack manipulation) routines, pretty much everything else *could* be done in C, but that doesn't invalidate the point. *nods* I think it's safe to say that none of pure C, pure Lisp, or pure Python are really capable of being used as the *sole* language to build an operating system. *nods* It's also safe to say that this is a largely irrelevant point. It would probably only be of academic interest to try to do something like that. Any practical attempt would not think more than twice of resorting to a little glue in assembler or in the form of canned byte sequences built by hand and stuck into the appropriate places in memory... -Peter Indeed indeed. Once must remain focused and ask oneself what he/she is attempting to achieve. In all likelihood, a little asm/c/python glue work won't hurt the objective, especially given that doing otherwise would entail a very _low level_ reworking of Python that would take as much and likely more effort and skill than to resort to asm/c when Python falls incapable. One could do a Python-Lisp OS w/ Lisp used for the Python incapable areas, but you would near entirely loose the benefits of Lisp in that respect--- it would have to be so low-level, could you call it Lisp? (A question someone else here posed in this thread.) - Arich -- http://mail.python.org/mailman/listinfo/python-list
Re: DOS problem (simple fix??)
Gavin Bauer wrote: My DOS window (running in windows ME) closes the second it finishes running my programs. As you can imagine, this makes it hard to see the results. I've gotten in the habit of putting raw_input(Press enter to exit) at the end of every program, and in addition to being pain in the butt, it often fails to work. Being new to programming in general, I make more mistakes than most people. My programs often have errors before they get to my raw_input command. They then display the error and immediately close. It is naturally a lot easier to fix an error when you know what the error is. This makes debugging even more annoying than it ordinarily would be, if you can imagine that. I've heard that it should be a simple preference fix, but I've asked around and no one seems to know how. I presume this means you are starting the program by the time-honored expedient of double-clicking on it. For debugging you would probably find it more satisfactory to run your programs from the command line, and there's a FAQ that explains how at http://www.python.org/doc/faq/windows.html If that isn't simple enough then please let me know, as it's *supposed* to be. Thank you, and please make all answers simple enough to be understood by a highschool student and his father :) . If you wanted to get really adventurous you could try tweaking the command that Windows runs when you double-click a Python script, but we'll leave that for another time. Welcome to Python! regards Steve -- Steve Holden http://www.holdenweb.com/ Python Web Programming http://pydish.holdenweb.com/ Holden Web LLC +1 703 861 4237 +1 800 494 3119 -- http://mail.python.org/mailman/listinfo/python-list
Re: The limitation of the Photon Hypothesis
Steve Horsley wrote: bill wrote: Please reply to [EMAIL PROTECTED], thank you ! No - I'll reply to the newsgroup, if you don't mind. The limitation of the Photon Hypothesis snip THE UNCERTAINTY PRINCIPLE IS UNTENABLE Big snip You cannot use classical theory to disprove quantum theory that easily. The uncertainty is quantum in origin, and not just an artifact of classical mechanics applied to clumsy measurement. You don't convince me. Also, I think you probably accidentally posted to the wrong newsgroup. Steve No, he deliberately posted to the wrong newsgroup. But that's because there isn't a right newsgroup for this kind of twaddle (except possibly alt.rubbish.alternate.universe). You have just marked yourself as a noob, since this hoary old favorite seems to appear about ten times a year. Welcome to Usenet! regards Steve -- Steve Holden http://www.holdenweb.com/ Python Web Programming http://pydish.holdenweb.com/ Holden Web LLC +1 703 861 4237 +1 800 494 3119 -- http://mail.python.org/mailman/listinfo/python-list
RE: there's a socket.sendall(), so why no socket.recvall()?
Irmen de Jong wrote: Subject says it all; there's a socket.sendall(), so why no socket.recvall()? Good question! Something like: # Receive reply. data = [] while True: try: chunk = conn.recv(8192) except Exception, x: if x.args[0] != 10035: raise x else: if chunk == '': break data.append(chunk) If you call .makefile() and then .read() the _fileobject, you get the same behavior (only better). Adding recvall would just duplicate that, I think. But that's desirable IMO. Robert Brewer MIS Amor Ministries [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: tuples vs lists
worzel wrote: Cheers - thanks for the feedback guys - pretty much answers the question for me. 'Two-Pull' it is then, thanks. Well, it might be Two-Pull in American, but in English it's tyoopl -- NOT choopl (blearch!). I've also heard people say tuppl. So, basically, say whatever you want. Language is about communication :-) you-say-tomato-ly y'rs - steve -- Steve Holden http://www.holdenweb.com/ Python Web Programming http://pydish.holdenweb.com/ Holden Web LLC +1 703 861 4237 +1 800 494 3119 -- http://mail.python.org/mailman/listinfo/python-list
Weekly Python Patch/Bug Summary
Patch / Bug Summary
___
Patches : 267 open ( +6) / 2727 closed ( +9) / 2994 total (+15)
Bugs: 798 open ( -3) / 4748 closed (+15) / 5546 total (+12)
RFE : 165 open ( +0) / 140 closed ( +1) / 305 total ( +1)
New / Reopened Patches
__
Remove witty comment in pydoc.py (2005-01-01)
CLOSED http://python.org/sf/1094007 opened by Reinhold Birkenfeld
Docs for file() vs open() (2005-01-01)
CLOSED http://python.org/sf/1094011 opened by Reinhold Birkenfeld
Improvements for shutil.copytree() (2005-01-01)
CLOSED http://python.org/sf/1094015 opened by Reinhold Birkenfeld
xml.dom.minidom.Node.replaceChild(obj, x, x) removes child x (2005-01-01)
http://python.org/sf/1094164 opened by Felix Rabe
os.py: base class _Environ on dict instead of UserDict (2005-01-02)
http://python.org/sf/1094387 opened by Matthias Klose
add Bunch type to collections module (2005-01-02)
http://python.org/sf/1094542 opened by Steven Bethard
self.button.pack() in tkinter.tex example (2005-01-03)
http://python.org/sf/1094815 opened by [N/A]
fixes urllib2 digest to allow arbitrary methods (2005-01-03)
http://python.org/sf/1095362 opened by John Reese
Argument passing from /usr/bin/idle2.3 to idle.py (2003-11-30)
http://python.org/sf/851459 reopened by jafo
fix for trivial flatten bug in astgen (2005-01-04)
http://python.org/sf/1095541 opened by DSM
exclude CVS conflict files in sdist command (2005-01-04)
http://python.org/sf/1095784 opened by Wummel
Fix for wm_iconbitmap to allow .ico files under Windows. (2005-01-05)
http://python.org/sf/1096231 opened by John Fouhy
Info Associated with Merge to AST (2005-01-07)
http://python.org/sf/1097671 opened by Kurt B. Kaiser
Direct framework linking for MACOSX_DEPLOYMENT_TARGET 10.3 (2005-01-07)
http://python.org/sf/1097739 opened by Bob Ippolito
Encoding for Code Page 273 used by EBCDIC Germany Austria (2005-01-07)
http://python.org/sf/1097797 opened by Michael Bierenfeld
Patches Closed
__
locale.getdefaultlocale does not return tuple in some OS (2004-10-21)
http://python.org/sf/1051395 closed by rhettinger
imghdr -- identify JPEGs in EXIF format (2003-06-08)
http://python.org/sf/751031 closed by rhettinger
Remove witty comment in pydoc.py (2005-01-01)
http://python.org/sf/1094007 closed by rhettinger
Docs for file() vs open() (2005-01-01)
http://python.org/sf/1094011 closed by rhettinger
Improvements for shutil.copytree() (2005-01-01)
http://python.org/sf/1094015 closed by jlgijsbers
a new subprocess.call which raises an error on non-zero rc (2004-11-23)
http://python.org/sf/1071764 closed by astrand
Argument passing from /usr/bin/idle2.3 to idle.py (2003-11-30)
http://python.org/sf/851459 closed by jafo
@decorators, including classes (2004-08-12)
http://python.org/sf/1007991 closed by jackdied
Convert glob.glob to generator-based DFS (2004-04-27)
http://python.org/sf/943206 closed by jlgijsbers
Make cgi.py use email instead of rfc822 or mimetools (2004-12-06)
http://python.org/sf/1079734 closed by jlgijsbers
New / Reopened Bugs
___
marshal.dumps('hello',0) Access violation (2005-01-03)
CLOSED http://python.org/sf/1094960 opened by Mark Brophy
General FAW - incorrect most stable version (2005-01-03)
http://python.org/sf/1095328 opened by Tim Delaney
Python FAQ: list.sort() out of date (2005-01-03)
CLOSED http://python.org/sf/1095342 opened by Tim Delaney
Bug In Python (2005-01-04)
CLOSED http://python.org/sf/1095789 opened by JastheAce
Macintosh references in the docs need to be checked. (2005-01-04)
http://python.org/sf/1095802 opened by Jack Jansen
The doc for DictProxy is missing (2005-01-04)
http://python.org/sf/1095821 opened by Colin J. Williams
Apple-installed Python fails to build extensions (2005-01-04)
http://python.org/sf/1095822 opened by Jack Jansen
time.tzset() not built on Solaris (2005-01-05)
http://python.org/sf/1096244 opened by Gregory Bond
sys.__stdout__ doco isn't discouraging enough (2005-01-05)
http://python.org/sf/1096310 opened by Just van Rossum
_DummyThread() objects not freed from threading._active map (2004-12-22)
http://python.org/sf/1089632 reopened by saravanand
Example needed in os.stat() (2005-01-06)
CLOSED http://python.org/sf/1097229 opened by Facundo Batista
SimpleHTTPServer sends wrong Content-Length header (2005-01-06)
http://python.org/sf/1097597 opened by David Schachter
urllib2 doesn't handle urls without a scheme (2005-01-07)
http://python.org/sf/1097834 opened by Jack Jansen
getsource and getsourcelines in the inspect module (2005-01-07)
CLOSED http://python.org/sf/1098134 opened by Björn Lindqvist
mailbox
Re: The best way to do web apps with Python?
worzel wrote: What is the best way to web developemnt with Python? Is there anything close to PHP style in-page script placement that can create and use other Python objects? I am not really interested in Zope (I believe that is more a CMS than anything else?) I am also looking for something a little more structured than a series of CGI Scripts. More ways than you can shake a stick at, but nowadays you should consider using WSGI if you want your code to be portable across many frameworks. The Web SIG worked very hard last year on defining this gateway interface, with the intention that it should become widely available, and implementations are available now on environments as diverse as mod_python and CherryPy. You can read about it in Philip Eby's excellent PEP at http://www.python.org/peps/pep-0333.html While on the topic - what is the expectataion of Python for this kind of stuff? Would one use Python for certain other things but turn to PHP for web apps - or would one use their Python skills in place of PHP? Python is a real programming language, whereas PHP was originally intended as a simple way of scripting web content. Since then it has grown to encompass many of the same features as Python, but since they were retrofitted rather than designed in they are sometimes kind of clunky (as, IMHO, is Perl, although in a different way). But there's a lot of good work been done in both PHP and Perl, and I'd usually recommend using existing functionality in either language over a just-for-the-sake-of-it rewrite in Python. But that could just be because I don't like re-inventing wheels. regards Steve -- Steve Holden http://www.holdenweb.com/ Python Web Programming http://pydish.holdenweb.com/ Holden Web LLC +1 703 861 4237 +1 800 494 3119 -- http://mail.python.org/mailman/listinfo/python-list
Re: Recent infoworld column
On Sat, 08 Jan 2005 13:14:17 -0500, Peter Hansen [EMAIL PROTECTED] wrote: Dwarf Electrician wrote: from a long time listener... http://www.infoworld.com/article/04/12/30/01OPstrategic_1.html Kudos for Roger Binns! From Mr. Udell himself: When people talk about the heroes of open source, you tend to hear such familiar names as Linus Torvalds, Larry Wall, Brendan Eich, Guido van Rossum, Monty Widenius, Miguel de Icaza, and Rasmus Lerdorf. No question about it: These people are my heroes. But so is Roger Binns, and so are the countless other unsung heroes of open source. For solving a host of vexing problems with quiet competence, and for doing it in ways that invite others to stand on their shoulders, I salute them all. That's recognition. Wow. -- Carlos Ribeiro Consultoria em Projetos blog: http://rascunhosrotos.blogspot.com blog: http://pythonnotes.blogspot.com mail: [EMAIL PROTECTED] mail: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Weekly Python Patch/Bug Summary
Kurt B. Kaiser wrote: Remove witty comment in pydoc.py (2005-01-01) CLOSED http://python.org/sf/1094007 opened by Reinhold Birkenfeld This is not a joke? :-) -- hilsen/regards Max M, Denmark http://www.mxm.dk/ IT's Mad Science -- http://mail.python.org/mailman/listinfo/python-list
Re: Working with recordsets
AdSR wrote: [EMAIL PROTECTED] wrote: Hi. I have one recorset that I would like to pass to 2 functions, one is for create an CSV file and the other one is to create a HTML file. The problem is that the recordset is totally read in the first function, and then when I pass it to the second funtion the recordset is in the last record. I've read docs, but I think that one cursor doesn't have something like movefirst() method. Anybody have an idea to solve this? Thank's. Try loading the whole recordset with the fetchall() method and use the resulting sequence in your functions. It won't be memory-efficient but it will be easy to do. AdSR Or, if this doesn't suit, try creating two separate cursors from the same connection and execute the same query on each. There's some chance that your database driver/backend combination will optimize the queries then. regards Steve -- Steve Holden http://www.holdenweb.com/ Python Web Programming http://pydish.holdenweb.com/ Holden Web LLC +1 703 861 4237 +1 800 494 3119 -- http://mail.python.org/mailman/listinfo/python-list
Re: Installing IPython on win2k
Dave Merrill wrote: Hi, I'm new to python, and ipython, but not to programming, having trouble getting ipython installed on windows 2000, python 233. Any help would be much appreciated; I'm sure I'm being some basic flavor of dense... First of all, rest assured that it does work (and quite easily) so welcome to Python and iPython and I hope the going's a bit smoother as you go along. Then downloaded ipython-0.6.6.zip and unzipped it. When I double-click setup.py, I get only a brief wait cursor; nothing else happens, and importing ipython as a test fails. First of all, ipython isn't really an import into python; you run it and it runs python (if you understand me). So when you've installed it, I think it puts an item on your start menu. On linux, it puts an executable ipython onto your path. I've just downloaded and run the setup.py, and it does create a Start Menu item which will start iPython. Look out for that and see if it does the business. Both files in the scripts dir, ipython and pycolor, have no filename extension, which seems odd to my newbie eye. I tried renaming them to .py, still no difference. This is a unixism. Some unix types decry the use of file extensions because the information the extension gives -- which executable program to use -- is already embedded in the first line of a file. My apologies for this basic question, and my no doubt ignorant flailing about. Very much looking forward to getting this working. Thanks, Dave Merrill Good luck and happy hunting TJG -- http://mail.python.org/mailman/listinfo/python-list
Re: Embedding a restricted python interpreter
Doug Holton [EMAIL PROTECTED] writes on Thu, 06 Jan 2005 20:34:31 -0600: ... Hi, there is a page on this topic here: http://www.python.org/moin/SandboxedPython The short answer is that it is not possible to do this with the CPython, but you can run sandboxed code on other virtual machines, such as Java's JVM with Jython, or .NET/Mono's CLR with Boo or IronPython. Zope contains a restrictedPython implementation. It uses a specialized compiler that prevents dangerous bytecode operations to be generated and enforces a restricted builtin environment. -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
Of course there are many performance bottleneck, CPU, memory, I/O, network all the way up to the software design and implementation. As a software guy myself I would say by far better software design would lead to the greatest performance gain. But that doesn't mean hardware engineer can sit back and declare this as software's problem. Even if we are not writing CPU intensive application we will certain welcome free performace gain coming from a faster CPU or a more optimized compiler. I think this is significant because it might signify a paradigm shift. This might well be a hype, but let's just assume this is future direction of CPU design. Then we might as well start experimenting now. I would just throw some random ideas: parallel execution at statement level, look up symbol and attributes predicitively, parallelize hash function, dictionary lookup, sorting, list comprehension, etc, background just-in-time compilation, etc, etc. One of the author's idea is many of today's main stream technology (like OO) did not come about suddenly but has cumulated years of research before becoming widely used. A lot of these ideas may not work or does not seems to matter much today. But in 10 years we might be really glad that we have tried. aurora [EMAIL PROTECTED] writes: Just gone though an article via Slashdot titled The Free Lunch Is Over: A Fundamental Turn Toward Concurrency in Software [http://www.gotw.ca/publications/concurrency-ddj.htm]. It argues that the continous CPU performance gain we've seen is finally over. And that future gain would primary be in the area of software concurrency taking advantage hyperthreading and multicore architectures. Well, another gain could be had in making the software less wasteful of cpu cycles. I'm a pretty experienced programmer by most people's standards but I see a lot of systems where I can't for the life of me figure out how they manage to be so slow. It might be caused by environmental pollutants emanating from Redmond. -- http://mail.python.org/mailman/listinfo/python-list
Re: there's a socket.sendall(), so why no socket.recvall()?
Robert Brewer wrote: Irmen de Jong wrote: Subject says it all; there's a socket.sendall(), so why no socket.recvall()? [...] If you call .makefile() and then .read() the _fileobject, you get the same behavior (only better). Adding recvall would just duplicate that, I think. But that's desirable IMO. Hm, I didn't consider makefile(). But I'm not sure if that works in all cases. Until now, I've been using a loop rather like the one you posted. But, as I pointed out earlier, there is the MSG_WAITALL option on various platforms (Linux for instance). So instead of sticking it in an explicitly programmed loop in Python, or using an extension module such as this one: http://mail.python.org/pipermail/python-list/2003-January/143051.html , I'd rather have a recvall method on the socket object that essentially uses MSG_WAITALL if available, and uses a loop construction if not. I may even write a patch for socketmodule.c right now :-D --Irmen de Jong -- http://mail.python.org/mailman/listinfo/python-list
Re: tuples vs lists
Steve Holden wrote: Well, it might be Two-Pull in American, but in English it's tyoopl -- NOT choopl (blearch!). I've also heard people say tuppl. Probably the same ones who attend Tuppl-ware parties. --Irmen -- http://mail.python.org/mailman/listinfo/python-list
Re: windows mem leak
Bob Smith wrote: Does the Win32 port of Python have a memory leak? I have some code that runs flawlessly on Linux, but bombs after a few hours on Windows. It's threaded and uses a lot of memory. Thanks! Yes, that's a well-known problem. Code that runs with a few errors will port without any trouble at all to Windows, but once it runs flawlessly on Linux it starts to leak memory on Windows. The PSU suspects a plot in Redmond, the basic details of which ar -- Steve Holden http://www.holdenweb.com/ Python Web Programming http://pydish.holdenweb.com/ Holden Web LLC +1 703 861 4237 +1 800 494 3119 -- http://mail.python.org/mailman/listinfo/python-list
losing CGI variables in os.environ in Python 2.4
Did something change between 2.3 and 2.4 that would affect os.environ being populated with CGI variables when using the BaseHTTPServer/CGIHTTPServer? I received a bug report from someone trying to run my wiki/blog software, Leonardo[1] under Python 2.4 on Windows 2000. I was able to reproduce the problem under Python 2.4 on Windows XP Pro but confirmed that it worked fine under Python 2.3. Simply printing out os.environ at the point things like PATH_INFO are extracted by Leonardo revealed that os.environ contained no CGI-related variables when run under Python 2.4 but did contain them under 2.3 I can't see in the code for the http server modules that anything changed in this area. Am I missing something? Thanks in advance. James Tauber http://jtauber.com/blog/ [1] http://jtauber.com/leonardo -- http://mail.python.org/mailman/listinfo/python-list
Re: Installing IPython on win2k
Tim G wrote in message news:[EMAIL PROTECTED] Dave Merrill wrote: Hi, I'm new to python, and ipython, but not to programming, having trouble getting ipython installed on windows 2000, python 233. Any help would be much appreciated; I'm sure I'm being some basic flavor of dense... First of all, rest assured that it does work (and quite easily) so welcome to Python and iPython and I hope the going's a bit smoother as you go along. I'm having fun with python itself, but feeling a little constrained in the IDE and debugger departments. (Not to mention the clues I haven't got...). Then downloaded ipython-0.6.6.zip and unzipped it. When I double-click setup.py, I get only a brief wait cursor; nothing else happens, and importing ipython as a test fails. First of all, ipython isn't really an import into python; you run it and it runs python (if you understand me). So when you've installed it, I think it puts an item on your start menu. On linux, it puts an executable ipython onto your path. I've just downloaded and run the setup.py, and it does create a Start Menu item which will start iPython. Look out for that and see if it does the business. Removed the files I'd unzipped and started over, putting a fresh unzip in Program Files. Ran setup.py while watching the windows task list, and pythonw ran for just a second, then disappeared. I saw no other signs of anything running, and there's no shortcut for ipython in my start menu. Both files in the scripts dir, ipython and pycolor, have no filename extension, which seems odd to my newbie eye. I tried renaming them to .py, still no difference. This is a unixism. Some unix types decry the use of file extensions because the information the extension gives -- which executable program to use -- is already embedded in the first line of a file. So what do I do to try ipython directly, bypassing the shortcut (since I can make my own later)? I tried right-click on scripts/ipython, Open With, and chose python, but got only a quick DOS window. Now what? Thanks, Dave Merrill -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Operating System???
Is an OS written in Lisp also ludicrous? Because it's been done. Can you point me to this? I'd like to see how truly Lisp it is. My first guess would be -- not very. And I'd like to install it on my PC. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Operating System???
Well can you describe what kind of things you want to do exactly? My guess is you are not out to develop a new algorithm for virtual memory or task scheduling. There are many parts to an OS shell. An example is the command line, i.e. bash and the like in Unix, and cmd.exe in Windows. In Windows, Windows Explorer could be considered part of the shell, as well as the start menu and all that user-specific stuff. Basically you need to pick your OS, and then find out what the API to program the shell to would be. e.g. in Windows you would do it with the Win32 API. This will let you do things like delete and create files, interact with user structures, the registry, etc. OR, as a first stab -- I would just write a prototype. i.e., don't tie it to a real OS. Just pretend you have your own users, your own file system, your own display space, etc. This will help you get a much better idea of what you want to do. David Brown [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] So how would I make an OS Shell? -- http://mail.python.org/mailman/listinfo/python-list
Re: EOF for binary?
In [EMAIL PROTECTED], flamesrock
wrote:
os.path.getsize(infile) = infile.tell()
Because that returns the error:
# File /usr/lib/python2.3/posixpath.py, line 142, in getsize
#return os.stat(filename).st_size
#TypeError: coercing to Unicode: need string or buffer, file found
for me.
This error message gives a good hint what's wrong with your code snippet.
f = open('tmp.txt')
os.path.getsize(f)
Traceback (most recent call last):
File stdin, line 1, in ?
File /usr/lib/python2.3/posixpath.py, line 142, in getsize
return os.stat(filename).st_size
TypeError: coercing to Unicode: need string or buffer, file found
Something expected a string instead of a file object.
os.path.getsize(tmp.txt)
28190L
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: escape string for command line
In [EMAIL PROTECTED], Ksenia
Marasanova wrote:
I have a simple ecard creation script on a website, where user can add
text to a graphic. I use ImageMagick for it:
# template_file = path to image template file
# new_file = path to generated file
# text = user input
command = '''convert %s -font OfficinaSanITC-BookOS -pointsize 12
-fill #8C2F48 -draw gravity north text 0,26 '%s' %s''' % (
template_file, text, new_file)
system(command)
I was wondering, is there a general way to escape the string entered
by the user, to prevent code injection into command line?
Take a look at the string-escape encoding:
evil = '; rm -rf /;
command = echo '%s'
print command % evil.encode('string-escape')
echo '\'; rm -rf /;'
Will it
always be safe, even when binary data is submitted through POST?
Don't know if it's always safe. Unprintable bytes like 0x00 will be
escaped as '\x00'.
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: Installing IPython on win2k
Fernando replied to a similar post of mine on the IPython list, and had a suggestion that for some unknown reason, worked. Or rather, what's unknown is why normal setup failed. For the benefit of anyone else who has this issue, I unzipped the files into C:\Program Files\ipython-0.6.6 ...then opened a DOS window, and did the following two cmds: cd C:\Program Files\ipython-0.6.6 C:\Program Files\Python23\python.exe setup.py install Tons of DOS cmds spat out, the shortcut was created, and launching it brought up the config wizard, then ipython. I'd really love it if ipython could be invoked in the current debugger context in PyDev under Eclipse. Is there any way to do that? Thanks again, Dave Merrill -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
Peter Hansen [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] John Roth wrote: I have yet to write a multi-thread program for performance reasons. If we include in the set of things covered by the term performance not only throughput, but also latency, then I suspect you actually have written some multithreaded programs for performance reasons. *I* certainly have: that's easily the reason for threading in 95% of the cases I've dealt with, and I suspect those of many others. Actually, I've never written a multi-threaded program for any reason. There were only two times I had to deal with concurrency: one was a very nice co-routine implementation (HASP, the predecessor to the JES2 subsystem on MVS), and the other was event driven (on an IBM SP). The former system didn't have a threading library, let alone a lightweight one, and the event driven design was a lot simpler for the second application - and I did consider all three options. John Roth -Peter -- http://mail.python.org/mailman/listinfo/python-list
Documenting data members
Hello,
I have a custom module which among others contains a dictionary, acting as a
constant. I want to document it, but no matter what I do, it doesn't show
up in `pydoc`. For example, the following doesn't work:
A dictionary of the namespaces.
xmlns = {
...
}
or
xmlns = {
A dictionary of the namespaces.
...
}
Bottom line: how do I document data members?
I also have another documentation question:
In a module which I install, the file starts with a comment containing a
license header, to then be followed by a Python documentation string(this
module ...). The problem is that in pydoc, I get the uninteresting license
header as documentation, instead of the doc string. I want to have the
license header at the top.
Is this somehow fixable? That the doc string, instead of the license header,
shows up in pydoc despite the latter being first in the file?
Cheers,
Frans
--
http://mail.python.org/mailman/listinfo/python-list
Re: escape string for command line
I was wondering, is there a general way to escape the string entered
by the user, to prevent code injection into command line?
Take a look at the string-escape encoding:
evil = '; rm -rf /;
command = echo '%s'
print command % evil.encode('string-escape')
echo '\'; rm -rf /;'
Cool, thanks! Next time I'll study stdlib better before asking the question :)
--
Ksenia
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python Operating System???
My experiment, Cleese, was making progress before I got distracted by other things. The approach was a micro-kernel in C made up of the CPython bytecode interpreter with the file-related calls to libc ripped out and some bare-metal port read/writes and memory operations exposed to Python as built-in functions. Everything else could then be written in pure Python. Dave Long was able to write a VGA driver in Python and an implementation of Sokoban that used it. You could then boot your machine to Sokoban :-) I should probably get back to it at some stage. see http://cleese.sourceforge.net/ James Tauber http://jtauber.com/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Python Installation
I need to install Python on a number of laptop computers (at least a dozen). I am needing to install Python 2.4, pycrypto, win32all, wxPython, and pyCurl. Can anyone tell me an easy way to install these onto the laptops? Ideally I would like to have a single executable to handle everything for me. I have also looked into using NSIS to handle the installation, but am still unaware how to install the modules that I need easily. Does anyone have any suggestions? -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Installation
For what its worth, I am running Windows XP Pro on all of these machines. -- http://mail.python.org/mailman/listinfo/python-list
Re: python3: 'where' keyword
On Sat, 08 Jan 2005 12:53:05 -0500, Peter Hansen [EMAIL PROTECTED] wrote: Andrey Tatarinov wrote: print words[3], words[5] where: words = input.split() - defining variables in where block would restrict their visibility to one expression Then your example above doesn't work... print takes a sequence of expressions, not a tuple as you seem to think. I found it strange that he had chosen to make the example with print, that is a statement. I'm not sure how could it be made to work with both expressions and statements, it just seems strange... Overall, I found the idea interesting. It seems like a obvious counterpart to with, in the sense that both act as modifiers to the scoping rules. I think it can be made to work, and that it would lead to elegant readable code, but there are still lots of things to consider: exception handling, fast name lookup in the where block, access to symbols outside the where block, just to name a few. -- Carlos Ribeiro Consultoria em Projetos blog: http://rascunhosrotos.blogspot.com blog: http://pythonnotes.blogspot.com mail: [EMAIL PROTECTED] mail: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Ranting about the state of Python IDEs for Windows
Carlos Ribeiro wrote: Oh well. A mailing list is not the most appropriate place for rants (a blog is better), but it's still better than keeping it for myself. I'm frustrated. My search for a good IDE to support my activities -- doing development for Python in the Windows environment -- are not being succesful as I had originally dreamt. I have big constraints on what can I do now; money is not an option, and my current machine is still useful but it's below par for more advanced stuff. It's my fault? Probably. But it's all that I have -- a 500MHz PC with 64MB and Win98 SE. It has to be Windows, for reasons beyond my control (read wife and kids :-). Look at http://www.pspad.com/en/index.html. Very good and smart editor for Python and other languages. You even can set menu for brazillian portuguese! And it's free... A dica vem com um certo atrazo, mas espero que seja util. -- http://mail.python.org/mailman/listinfo/python-list
Re: A Fundamental Turn Toward Concurrency in Software
On Sat, 08 Jan 2005 11:52:03 -0800, aurora [EMAIL PROTECTED] wrote: One of the author's idea is many of today's main stream technology (like OO) did not come about suddenly but has cumulated years of research before becoming widely used. A lot of these ideas may not work or does not seems to matter much today. But in 10 years we might be really glad that we have tried. One thing that I would love to see included in Python is a native library for fast inter-process communication, including support for message passing primitives and remote object calls. I know that there are a number of offerings in this arena: third party libraries such as Pyro, message passing libraries such as the ones from ScyPy, and standard libraries such as the XMLRPC ones. The key requirements are: fast, and native. By fast, I mean, highly optimized, and at least as fast (in the same order of magnitude, let's say) as any other competitive environment available. By native, it means that it has to be included in the standard distribution, and has to be as transparent and convenient as possible. In other words, it has to feel like a native part of the language. -- Carlos Ribeiro Consultoria em Projetos blog: http://rascunhosrotos.blogspot.com blog: http://pythonnotes.blogspot.com mail: [EMAIL PROTECTED] mail: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Another look at language comparisons
On Sat, 08 Jan 2005 14:18:15 +0100, Jan Dries wrote: snip The bottom line of the article is that languages authored by men with beards are more successful than those authored by people without beards. At least the anecdotical evidence to that is overwhelming :-) And there is hope for Python, as Guido has recently been seen with a beard :-) http://www.tbray.org/ongoing/When/200x/2004/12/08/-big/IMG_3061.jpg Regards, Jan What about languages USED by men with beards? There may be hope for me yet. Regards, Rick -- http://mail.python.org/mailman/listinfo/python-list
printing line numbers for debugging purpose
Hi, All of the methods from my program return None on error (i.e; I do not want to assert and have the program exit). Is it possible to print the current source file name/line number ? ex: in C/C++ I would use the macros __FILE__ and __LINE__. Regards, Philippe -- *** Philippe C. Martin SnakeCard LLC www.snakecard.com *** -- http://mail.python.org/mailman/listinfo/python-list
Re: EOF for binary?
ahh..that does make sense. But maybe getsize() should have a way of inferring what file is specified. I might actually submit a request.. -- http://mail.python.org/mailman/listinfo/python-list
Re: printing line numbers for debugging purpose
Philippe C. Martin wrote:
Hi,
All of the methods from my program return None on error (i.e; I do not
want to assert and have the program exit).
Is it possible to print the current source file name/line number ?
ex: in C/C++ I would use the macros __FILE__ and __LINE__.
Consider something like this:
#!/usr/bin/env python
def main():
raise RuntimeError('whatever')
if __name__ == '__main__':
try:
main()
except:
import sys, traceback
t, v, tb = sys.exc_info()
traceback.print_tb(tb)
--
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Re: Embedding a restricted python interpreter
Dieter Maurer [EMAIL PROTECTED] writes: It uses a specialized compiler that prevents dangerous bytecode operations to be generated and enforces a restricted builtin environment. Does it stop the user from generating his own bytecode strings and demarshalling them? -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Operating System???
Roose [EMAIL PROTECTED] writes: Is an OS written in Lisp also ludicrous? Because it's been done. Can you point me to this? I'd like to see how truly Lisp it is. http://en.wikipedia.org/wiki/Lisp_machine My first guess would be -- not very. And I'd like to install it on my PC. Although written with federal funds at a university, it was never released to the public, but was instead offered for sale from some companies. The conflicts over this led to the birth of the free software movement. Also, it was never intended to run on PC's (which didn't exist at that time). It needed special hardware that was built for the purpose of running Lisp. Lately there are people trying to program PC's to simulate the Lisp hardware and to get the Lisp Machine software released (now that the commercial market for it has long since dried up). However, both of those projects have a ways to go. -- http://mail.python.org/mailman/listinfo/python-list
Re: windows mem leak
Steve Holden wrote:
Bob Smith wrote:
Does the Win32 port of Python have a memory leak? I have some code
that runs flawlessly on Linux, but bombs after a few hours on Windows.
It's threaded and uses a lot of memory.
Thanks!
Yes, that's a well-known problem. Code that runs with a few errors will
port without any trouble at all to Windows, but once it runs flawlessly
on Linux it starts to leak memory on Windows. The PSU suspects a plot in
Redmond, the basic details of which ar
Oh, the humor of it all ;)
Attached is the code. Run it yourself and see. You too Peter. Be gentle
with me, this was my first attempt with threads.
import os
import urllib
import socket
import time
import Queue
import threading
##
# Network Section #
##
socket.setdefaulttimeout(30)
networks = []
hosts = []
subnets = []
# Add the network 192.168.0 possibility to networks.
networks.append(192.168.0.)
# Generate and add networks 192.168.1-255 to networks.
n = 0
while n 255:
n = n + 1
networks.append(192.168.%s. %(n))
# Generate and add hosts 1-254 to hosts.
for network in networks:
h = 1
# Add the n.n.n.0 host possibility to hosts.
hosts.append(network+str(h))
while h 254:
h = h + 1
hosts.append(network+str(h))
# This should equal 65024 or 256 * 254
# because 256 possibilities are OK in the 3rd octet,
# but only 254 possibilities are OK in the 4th octet...
# we exclude 0 and 255.
print There are, len(hosts), total hosts (192.168.256*254) in the hosts
list.
a = 0
b = 254
## Add the 192.168.0 net list to the subnets list.
subnets.append(hosts[0:254])
##print subnets
##print len(subnets)
## Add the 192.168.1-254 net lists to the subnets list.
for x in xrange(254):
a = a+254
b = b+254
subnets.append(hosts[a:b])
##print subnets
##print len(subnets)
## Add the 192.168.255 net list to the subnets list.
subnets.append(hosts[64770 :65024])
##print subnets[0]
print There are, len(subnets), class C network lists in the subnets list.
##
# Queue Section #
##
# Create a queue of urls to feed the threads
# Make it so that the queue only contains 256 items
nmap_queue = Queue.Queue(256)
for subnet in subnets:
nmap_queue.put(subnet)
###
# Thread Section #
###
class prac(threading.Thread):
def run(self):
net = nmap_queue.get()
for ip in net:
Y = os.popen('nmap -sT -p 80 -P0 -n %s' %ip)
data = Y.read()
Y.close()
if 'open' in data:
O = file('opened.txt', 'a')
print O, ip
O.close()
elif 'closed' in data:
C = file('closed.txt', 'a')
print C, ip
C.close()
elif 'filtered' in data:
F = file('filtered.txt' , 'a')
print F, ip
F.close()
else:
V = file('other.txt', 'a')
print V, data, ip
V.close()
threads = []
for i in xrange(256):
go = prac()
threads.append(go)
for thread in threads:
thread.start()
while threading.activeCount() 1:
print str(threading.activeCount()), threads running incl. main
time.sleep(1)
--
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Re: Pre/Postconditions with decorators
On Fri, 7 Jan 2005 20:01:50 +0200, George Sakkis [EMAIL PROTECTED] wrote: Hi George, it would be nice to see how you have tackled the task. Maybe we will have a checker module in Python one day... ;-) I posted my module on http://rafb.net/paste/results/voZYTG78.html and its unit test on http://rafb.net/paste/results/MYxMQW95.html. Any feedback will be appreciated. Okay, nice. Unresolved Problems: 1) How do you handle duck types, i.e. a method that accepts StringIO, cStringIO or any other object that has a .readlines(), .seek() and .read() method? 2) How do you turn off the type checking for production code? Otherwise I quite like it. Please publish it somewhere. Stephen. -- http://mail.python.org/mailman/listinfo/python-list
Re: Pre/Postconditions with decorators
Stephen Thorne [EMAIL PROTECTED] writes: Unresolved Problems: 1) How do you handle duck types, i.e. a method that accepts StringIO, cStringIO or any other object that has a .readlines(), .seek() and .read() method? That should really be done through having those classes inherit a file-operations mixin, or else through interfaces (which might get added to Python). 2) How do you turn off the type checking for production code? It should be left on. Leaving it in for development and turning it off for production is like wearing a parachute during ground training and taking it off once you're in the air. -- http://mail.python.org/mailman/listinfo/python-list
