Re: adding a new line of text in Tk
nigel wrote: w =Label(root, text=Congratulations you have made it this far,just a few more questions then i will be asking you some) The problem i have is where i have started to write some textCongratulations you have made it this far,just a few more questions then i will be asking you some) I would actually like to add some text but it puts it all on one line.I would like to be able to tell it to start a new line. Just use \n in your string, e.g.: w = Label(root, text=Line 1\nLine 2\nLine 3) Or a triple-quoted string will do the trick: w = Label(root, text=Line 1 Line 2 Line 3) --Ben -- http://mail.python.org/mailman/listinfo/python-list
Re: SSH, remote login, and command output
Greetings! I'm working on a Python program for a small LAN of Linux systems running Gentoo, and I need a little help figuring out what I need to do it. So what I'd like to do is, from any given computer, log on to every other computer, run a certain command (which normally outputs text to the terminal), and store the output so I can use the aggregate statistics later in the program. I would normally something along the lines of SSH to do it, but I don't know what I would need to pull that off in Python. There's also one complication: the systems could be Gentoo systems, or they could be logged into Windows since they're dual booted. Considering all of this, can anyone give me some recommendation as to what library I should learn how to use to pull this off? I admit, I haven't done too much in the way of networks, but if someone can tell me what I need to do remote logins in this way, I'll do what I can to make it work. Thanks a million! Spire _ Is your PC infected? Get a FREE online computer virus scan from McAfee® Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963 -- http://mail.python.org/mailman/listinfo/python-list
Re: detecting drives for windows and linux
Alle 03:17, domenica 26 marzo 2006, BWill ha scritto: Hi, I'm writing a file browser, but I'm not sure how I could go about detecting the drives available I was just asking a similar question some days back. I'm planning to try a file catalogger. I just remember something about Win32API, but I didn't find anything on the linux side. Frankly I got some curious info that concerns 'Bacula', disk backup. And a part of it is use to browse and catalog file. I think we should read some line of code on that program. F -- http://mail.python.org/mailman/listinfo/python-list
Re: Comparisons and singletons
Alan asked: 2. If I really want a value True will I ever go astray with the test: if a is True: a = True b = 1. c = 1 a is True, b is True, c is True (True, False, False) Ziga Seilnacht [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] I think that True and False, although they were added in version 2.3, were not true singeltons until version 2.4. OK, but Python 2.3 yields the same result as above. Ziga wrote: You should finish reading the PEP, see especially this part: - Don't compare boolean values to True or False using == Yes: if greeting: No:if greeting == True: Worse: if greeting is True: I do not think this is relevant to the question I asked, which was how to test for a value of True, if that's what I really want. I think the outcome of this discussion has been: use 'is'. Thanks, Alan -- http://mail.python.org/mailman/listinfo/python-list
Re: Extending Methods Vs Delegates
I am sorry I couldn't reply sooner! Alex, Python in a nutshell is my bible and I take it virtually everywhere! Seriously, I would highly recommend it to anyone with a little to a lot of Python experience. I apologize for misinterpreting your passage on page 80. I will look much closer at your examples, links and ideas and I hope to straighten my knowledge on the subject of delegates! Thank you for hinting on the Template Method design pattern! Sorry for any misunderstanding! -- http://mail.python.org/mailman/listinfo/python-list
Re: Extending Methods Vs Delegates
vbgunz enlightened us with: I hope I've made some sense with this question. I ultimately wish to know just one real thing. Regardless of the name of the second example above, what is the purpose of calling a sub class method from a super class instance? What is the application to such a design? I've seen this style of programming before, in wxWidgets. The constructor of a class does various things. This is roughly what happens: class wxSomeClass(wxParent): def __init__(self, *args, **kwargs): # Do various things if not self.OnInit(): raise RuntimeError(Initialization failed) # Do other things that need to be done after custom # initialization def OnInit(self): return True This makes it easier to simply provide custom initialization, without having to redo everything in __init__. Calling the superclass' function is fine if you want to add behaviour before and/or after calling it. This example however lets you customize behaviour that's put in the middle of the __init__ function. Maybe an example will help? I hope so :) Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
Re: SSH, remote login, and command output
Spire 01 enlightened us with: So what I'd like to do is, from any given computer, log on to every other computer, run a certain command (which normally outputs text to the terminal), and store the output so I can use the aggregate statistics later in the program. I'd go for SSH indeed. I would normally something along the lines of SSH to do it, but I don't know what I would need to pull that off in Python. Easiest way would be the popen2 module. There's also one complication: the systems could be Gentoo systems, or they could be logged into Windows since they're dual booted. Then install Cygwin on the windows systems, and run the OpenSSH daemon there too. Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
Re: SSH, remote login, and command output
Spire 01 wrote in news:[EMAIL PROTECTED] in comp.lang.python: Greetings! I'm working on a Python program for a small LAN of Linux systems running Gentoo, and I need a little help figuring out what I need to do it. So what I'd like to do is, from any given computer, log on to every other computer, run a certain command (which normally outputs text to the terminal), and store the output so I can use the aggregate statistics later in the program. I would normally something along the lines of SSH to do it, but I don't know what I would need to pull that off in Python. There's also one complication: the systems could be Gentoo systems, or they could be logged into Windows since they're dual booted. Considering all of this, can anyone give me some recommendation as to what library I should learn how to use to pull this off? I admit, I haven't done too much in the way of networks, but if someone can tell me what I need to do remote logins in this way, I'll do what I can to make it work. I found this: http://pyssh.sourceforge.net/ which may be able to help you script ssh, alternativly use the subprocess module: http://docs.python.org/dev/lib/module-subprocess.html and translate however you would normaly script ssh. To connect to windows, you could install: http://sshwindows.sourceforge.net/ on your windows clients, but IIRC its win2K, XP only, or you could use cygwin (which the above is taken from). Rob. -- http://www.victim-prime.dsl.pipex.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: pondering about the essence of types in python
i dont think it's possible, to create proxy classes, but even if i did, calling remote methods with a `self` that is not an instance of the remote class would blow up. -tomer -- http://mail.python.org/mailman/listinfo/python-list
Slogan
In the style of the Pepsi 'Lip smakin' add of the 70's... In-dentin easy-readin object-orientin motivatin good buzzin literate programmin' abstractin fast runnin ever givin dynamic PYTHON! - I know, too much free time can be harmful ;-) - Pad. -- http://mail.python.org/mailman/listinfo/python-list
Re: detecting drives for windows and linux
BWill wrote: oh, I wasn't expecting a single solution for both platforms, just some good solutions thanks Are you aware that this idea is somewhat foreign to Linux? (Maybe you are and want to do it anyway?) Linux puts the whole file system (including mounted iPods, ISOs and NTFS drives) in one hierarchy. --Max -- http://mail.python.org/mailman/listinfo/python-list
Re:using else: interactive programme
Hello i will show you a short example of my programme. s = raw_input (ok lets see about doing some mathematics would you like to try some?) if s=='no': print Well you aint no fun sling your hook print END OF PROGRAMME print Go on sling your hook print Now let some one else have a go if s=='yes': print brilliant lets get cracking print We will start with some easy sums progressing to professor standard s = raw_input() s = raw_input (5 + 5 =) if s=='10': print Correct else: print you are not very smart it would seem print Or maybe you are just taking the piss if so behave print Are you ready to continue if s=='no': print Then go away if s=='yes': s = raw_input (5 + 5 =) if s=='10': print Well done else: print tut tut lets try some thing else The problem being my programme will not run,I believe it is because i have missused else: can some one please give me an example of how to correct this.Just to recap the programme runs fine until i get to. print well done I was under the impression that by using else: if the wrong answer was typed it would print tut tut lets try some thing else Any thought on this please. Thanks nige. -- http://mail.python.org/mailman/listinfo/python-list
Re: using else: interactive programme
I guess the indention got mixed up in your post, if I try to run it, I get error messages at each of the else: lines, because they're mis-indented. else should be indented like the if it belongs to, e.g (using underscores for spaces): if s=='10': print well done else: print something else Make sure you're using tabs/spaces consistently across the whole file, too. If I indent the else clauses correctly, I can run your script and it behaves the way you expeced. -- http://mail.python.org/mailman/listinfo/python-list
Re: image reduction script
Thanks, I'll give it a shot. Philippe Kamilche wrote: To reduce the color depth of an image in PIL: im = im.convert(mode=P, palette=Image.ADAPTIVE) -- http://mail.python.org/mailman/listinfo/python-list
Re: What's The Best Editor for python
For myself, I use kdevelop, KDE's development environment, it handles a multitude of languages very well, and python is one of them. It has solid project management, and a slew of other features. If you are looking for something solid, I would go with kdevelop. -- http://mail.python.org/mailman/listinfo/python-list
Re: pondering about the essence of types in python
gangesmaster on comp.lang.python said: TypeError: unbound method __init__() must be called with z instance as first argument (got x instance instead) == and the question is -- WHY? I think the answer would be: because it's an instance method. Its 'contract' it's to be bound to an object of a certain class. Would you like a different behaviour, you could decorate whatever method you need. I.e., turn your example into: class z(object): @staticmethod def __init__(self): self.blah=5 class x(object): def __init__(self): z.__init__(self) y = x() And this will work as you wish. You could have used classmethod as well with a properly tuned init, of course. but __mro__ is a readonly attribute, and deriving from instances is impossible (conn.modules.wx.Frame is a PROXY to the class)... and again -- WHY? these all look like INTENTIONAL limitations. someone went around and added type checks (which are NOT pythonic) into the cPython implementation. argh. why do that? I really think this happens because Python was designed to be casualerror-safe. This approach would probably lead to many programming errors. By the way, Python was designed to *discourage* such behaviours, not to prevent them. By the way, I didn't grasp what you would really like to do. You're saying you want to derive from instances, but then I see in your sample code you're creating a *class* derived from an object (I would expect you would like to derive an instance from an instance, and to 'twist' such new instance methods to your needs, which I think can be done as well). What's the difference between that and the use of __class__ ? class z(object): @staticmethod def __init__(self): self.blah=5 @staticmethod def met_stat(self): pass @classmethod def met_cls(self): pass def met_inst(self): pass class x(object): def __init__(self): z.__init__(self) y = x() class q(y.__class__): pass r = q() This work OK to me. Unless you want to do something like making y instance attributes become q class attributes, or you would like to set y instance attributes on all q instances, which could require a bit more of code but surely can be done. This would mix up a bit the class vs instance behaviour, though, e.g. changing a derived class instance attribute which is inherited from a parent instance would lead to a global attribute change, or would 'spawn' a new instance attribute for that particular instance? def derive_from(obj): class cls(object): def __getattr(self, name): return getattr(obj, name) return cls This seems to work for deriving read-only data from instances (no way to write back data). check types. DONT. the whole point of duck-typing is you DONT CHECK THE TYPES. you just work with objects, and instead of TypeError you'd get AttribiuteError, which is much better. AAARRGGGHH. You don't HAVE TO check types if you don't want. Just use @staticmethod everywhere in your classes. I mean, a METHOD is supposed to be class-related, and it's often useful to have it as such, (unexpected errors and behaviours might rise everywhere if not so), but you're never forced to use that. -- Alan Franzoni [EMAIL PROTECTED] - Togli .xyz dalla mia email per contattarmi. Rremove .xyz from my address in order to contact me. - GPG Key Fingerprint: 5C77 9DC3 BD5B 3A28 E7BC 921A 0255 42AA FE06 8F3E -- http://mail.python.org/mailman/listinfo/python-list
wired md5 hashing problem
Hello list-members i am in the process of writing a python script to backup my data. Now I would like to implement md5/sha1 hashes. # do md5 fingerprinting if config.get(global, crc) == md5: m = md5.new() # open the file f = open(fname, rb) while 1: block = f.read(1024*1024) if not block: break # generate the hash m.update(block) f.close() # write the results properly formated to a file fd = file(fname + .md5, w) fd.write(m.hexdigest()) fd.write( + fname + \n) fd.close() [EMAIL PROTECTED] md5sum -c backup.tar.bz2.md5 /fileservice/temp/backup.tar.bz2: FAILED md5sum: WARNING: 1 of 1 computed checksum did NOT match [EMAIL PROTECTED] cat backup.tar.bz2.md5 d41d8cd98f00b204e9800998ecf8427e /fileservice/temp/backup.tar.bz2 so the format should be okay, but whats wrong with my piece of code?! Greetings -- Mit freundlichen Grüßen Matthias Güntert signature.asc Description: This is a digitally signed message part -- http://mail.python.org/mailman/listinfo/python-list
Re: wired md5 hashing problem
Em Dom, 2006-03-26 às 16:56 +0200, Matthias Güntert escreveu: so the format should be okay, but whats wrong with my piece of code?! It looks ok for me. What does md5sum gives as the sum? -- Felipe. -- http://mail.python.org/mailman/listinfo/python-list
Module documentation
Just getting to grips with Python, a great language BUT With something like Java I can find the syntax of a method call with no problems, how do I do the same with Python? For example, using MySQLdb or SGMLParser I can see what the available methods are with dir, but how do I find out what parameters are needed and what they represent? Tony -- http://mail.python.org/mailman/listinfo/python-list
Re: Module documentation
Tony Burrows: With something like Java I can find the syntax of a method call with no problems, how do I do the same with Python? The basic syntax is just the name, with parameters in brakcets: object.method(par1, par2, ...) This is explained in the documentation, of course. how do I find out what parameters are needed and what they represent? This is documented in the library reference: http://docs.python.org/modindex.html You can also query the module for its docstrings: import os help(os) ... help(os.utime) Help on built-in function utime in module nt: ... -- http://mail.python.org/mailman/listinfo/python-list
Re: Extending Methods Vs Delegates
vbgunz [EMAIL PROTECTED] wrote: I am sorry I couldn't reply sooner! Alex, Python in a nutshell is my bible and I take it virtually everywhere! Seriously, I would highly recommend it to anyone with a little to a lot of Python experience. I apologize for misinterpreting your passage on page 80. I will look much closer at your examples, links and ideas and I hope to straighten my knowledge on the subject of delegates! Thank you for hinting on the Template Method design pattern! Sorry for any misunderstanding! Hey, no problem -- such a misunderstanding is always a shared responsibility, and as an author I need to take my part of the blame. Unfortunately, the root issue is that more and more common, ordinary, useful English words get expropriated by specialized technical meanings, making it almost impossible to discuss technical matters in ordinary English without *some* risk of misunderstanding (by the reader mistakenly seeing a specialized, technical meaning where the NORMAL English use of the word, possibly in a slightly metaphorical vein, is what the author meant). From function and procedure, to delegate and built-in, a growing number of words become risky!-) Funny enough, the problem is worst in English - because in many other languages, the specialized technical terms often use borrowed English words, so the other language's native terms remain available. Latin had similar luck wrt Greek a couple millennia ago -- all technical terms of philosophy were borrowed Greek words, so the risk of confusion was in fact much lower than it was in Greek;-). Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: detecting drives for windows and linux
Max [EMAIL PROTECTED] wrote: BWill wrote: oh, I wasn't expecting a single solution for both platforms, just some good solutions thanks Are you aware that this idea is somewhat foreign to Linux? (Maybe you are and want to do it anyway?) Linux puts the whole file system (including mounted iPods, ISOs and NTFS drives) in one hierarchy. Yes, but you may still want to distinguish (because, for example, hard linking doesn't work across filesystems, and mv is not atomic then). Running a df command is a good simple way to find out what drives are mounted to what mountpoints -- the mount command is an alternative, but its output may be slightly harder to parse than df's. Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: Module documentation
Tony Burrows wrote: Just getting to grips with Python, a great language BUT With something like Java I can find the syntax of a method call with no problems, how do I do the same with Python? For example, using MySQLdb or SGMLParser I can see what the available methods are with dir, but how do I find out what parameters are needed and what they represent? You can use the help function to get documentation on modules, functions, classes and objects. For example: import sgmllib help(sgmllib) # gives lots of information on the entire module help(sgmllib.SGMLParser) # gives information on the class help(sgmllib.SGMLParser.__init__) # gives initialisation information Unfortunately, because of the discrepancies between old-style and new-style classes, you can't always get decent help on objects. Consider this contrived example: parser = sgmllib.SGMLParser() # you'd usually be using a subclass help(parser) # gives information about class instance(object) Compare this to what happens when you get help on a file object: f = open(/etc/hosts) help(f) # gives information about class file(object) Personally, I feel that the whole new-style thing - making a class which inherits from something called object (of all the names that could have been chosen) - introduces a fair number of implementation-level issues that should have been hidden at the level of the language. I know that various other object-oriented languages have object or Object as a root class, but it's a dubious convention, unnecessary for the first seven or more years of Python's public life, and perhaps a prime candidate for elimination in the much-discussed-of-late Python 3000. Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Module documentation
On Sun, 26 Mar 2006 17:19:35 +0200, Rene Pijlman wrote: Tony Burrows: With something like Java I can find the syntax of a method call with no problems, how do I do the same with Python? The basic syntax is just the name, with parameters in brakcets: object.method(par1, par2, ...) This is explained in the documentation, of course. how do I find out what parameters are needed and what they represent? This is documented in the library reference: http://docs.python.org/modindex.html You can also query the module for its docstrings: import os help(os) ... help(os.utime) Help on built-in function utime in module nt: ... Wow! Thanks for that, I didn't know about the help command. The problem was that things like MySQLdb wasn't in the link you give (or at least, I couldn't find it - though poking around did take me to the database section and there it was). Tony -- http://mail.python.org/mailman/listinfo/python-list
Cookbook for beginners?
If you were going to name three or five essential recipes from the Python Cookbook suitable for beginners, what would you pick? Yes, this is for _Python for Dummies_, so idioms that aren't in the Cookbook are also fine. -- Aahz ([EMAIL PROTECTED]) * http://www.pythoncraft.com/ Look, it's your affair if you want to play with five people, but don't go calling it doubles. --John Cleese anticipates Usenet -- http://mail.python.org/mailman/listinfo/python-list
access mbx files?
Should I be able to access mail messages in Mahogany mail's mbx format using the Python mailbox module? If so, can someone please post a working example? If not, can you please point me to documentation of the file format or better yet Python code to parse it? Thanks, Alan Isaac -- http://mail.python.org/mailman/listinfo/python-list
Re: Extending Methods Vs Delegates
On Sun, 2006-03-26 at 07:21 -0800, Alex Martelli wrote:
vbgunz [EMAIL PROTECTED] wrote:
I am sorry I couldn't reply sooner! Alex, Python in a nutshell is my
bible and I take it virtually everywhere! Seriously, I would highly
recommend it to anyone with a little to a lot of Python experience.
I apologize for misinterpreting your passage on page 80. I will look
much closer at your examples, links and ideas and I hope to straighten
my knowledge on the subject of delegates!
Thank you for hinting on the Template Method design pattern! Sorry
for any misunderstanding!
Hey, no problem -- such a misunderstanding is always a shared
responsibility, and as an author I need to take my part of the blame.
Unfortunately, the root issue is that more and more common, ordinary,
useful English words get expropriated by specialized technical meanings,
making it almost impossible to discuss technical matters in ordinary
English without *some* risk of misunderstanding (by the reader
mistakenly seeing a specialized, technical meaning where the NORMAL
English use of the word, possibly in a slightly metaphorical vein, is
what the author meant). From function and procedure, to delegate
and built-in, a growing number of words become risky!-)
Funny enough, the problem is worst in English - because in many other
languages, the specialized technical terms often use borrowed English
words, so the other language's native terms remain available. Latin had
similar luck wrt Greek a couple millennia ago -- all technical terms of
philosophy were borrowed Greek words, so the risk of confusion was in
fact much lower than it was in Greek;-).
Of course, any language suffers that problem when the rise of a new
field is associated with it.
Medicine draws from Latin. For English speakers that is wonderful, a
whole language from which to assign specific meanings. But consider Mr.
DaVinci at one of his past-times, the dissection of rapidly decomposing
corpses for the secrets hidden within. That he might choose to spell
his description of the inside of an eye as vitreous humor, instead of
say, eye slime, didn't make it sound as impressive to him as the term
does to me today. I almost feel that a true appreciation for the
complexity of any endeavor must wait until its native language passed a
bit from the spot light.
While I can't speak for other fields, I believe that our linguistic
address space does limit our progress. Take list interpolations for
instance ... interpolation has other, specific meanings in other not so
far removed fields. When I first read about it, I had to backup and
think for a moment, if only to resolve the fact that yet another term is
overloaded.
And even our keyboards limit our space. I can create a tuple (), or a
list [], or a dict{}, but why can't I create another structure .. oh
wait, we are out of parenthesis like characters, and nobody has the
courage to recycle the of HTML fame pair.
Now, as I work on my mutable sequences PEP and implementation, I find
myself annoyed without a good, non-overloaded, way of naming an iter
friendly variant of a data store's normal __delitem__. Actually, this
wasn't more than a minute long problem, but the rate of collisions
within the English word space is a problem. At least English is pretty
friendly about adopted and synthetic words.
Cheers - Adam
--
http://mail.python.org/mailman/listinfo/python-list
Re: wired md5 hashing problem
What do you get when you type md5sum backup.tar.bz2? - Adam On Sun, 2006-03-26 at 16:56 +0200, Matthias Güntert wrote: Hello list-members i am in the process of writing a python script to backup my data. Now I would like to implement md5/sha1 hashes. # do md5 fingerprinting if config.get(global, crc) == md5: m = md5.new() # open the file f = open(fname, rb) while 1: block = f.read(1024*1024) if not block: break # generate the hash m.update(block) f.close() # write the results properly formated to a file fd = file(fname + .md5, w) fd.write(m.hexdigest()) fd.write( + fname + \n) fd.close() [EMAIL PROTECTED] md5sum -c backup.tar.bz2.md5 /fileservice/temp/backup.tar.bz2: FAILED md5sum: WARNING: 1 of 1 computed checksum did NOT match [EMAIL PROTECTED] cat backup.tar.bz2.md5 d41d8cd98f00b204e9800998ecf8427e /fileservice/temp/backup.tar.bz2 so the format should be okay, but whats wrong with my piece of code?! Greetings -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: wired md5 hashing problem
On Sun, 2006-03-26 at 16:56 +0200, Matthias Güntert wrote: Hello list-members i am in the process of writing a python script to backup my data. Now I would like to implement md5/sha1 hashes. # do md5 fingerprinting if config.get(global, crc) == md5: m = md5.new() # open the file f = open(fname, rb) while 1: block = f.read(1024*1024) if not block: break # generate the hash m.update(block) f.close() # write the results properly formated to a file fd = file(fname + .md5, w) fd.write(m.hexdigest()) fd.write( + fname + \n) fd.close() [EMAIL PROTECTED] md5sum -c backup.tar.bz2.md5 /fileservice/temp/backup.tar.bz2: FAILED md5sum: WARNING: 1 of 1 computed checksum did NOT match [EMAIL PROTECTED] cat backup.tar.bz2.md5 d41d8cd98f00b204e9800998ecf8427e /fileservice/temp/backup.tar.bz2 Hey, I found an md5 collision for your file! import md5 md5.new().hexdigest() 'd41d8cd98f00b204e9800998ecf8427e' [EMAIL PROTECTED] Include]$ md5sum # hit ^d at start d41d8cd98f00b204e9800998ecf8427e - Your file was empty when scanned. Without more information, I'd say that your file was empty when you ran your python code. But your code does work ... import md5 m = md5.new() # open the file fname=Python-2.4.2.tar.bz2 f = open(fname, rb ) while 1: block = f.read(1024*1024) if not block: break # generate the hash m.update(block) f.close() fd = file(fname + .md5, w) fd.write(m.hexdigest()) fd.write( + fname + \n) fd.close() [EMAIL PROTECTED] ~]$ python test2.py [EMAIL PROTECTED] ~]$ md5sum -c Python-2.4.2.tar.bz2.md5 Python-2.4.2.tar.bz2: OK - Adam -- http://mail.python.org/mailman/listinfo/python-list
maximum() efficency
I was looking at a Python function to find the maximum from a list. The original was more complicated; I simplified it. The built-in max() function can replace the simplified example, but not the original. def maximum(lst): maxval = lst[0] for i in xrange(1, len(lst)): v = lst[i] if maxval v: maxval = v return maxval Immediately I started thinking about ways to make this more efficient. My first thought was to use iterators: def maximum(lst): itr = iter(lst) maxval = itr.next() for v in itr: if maxval v: maxval = v return maxval Then I thought, I wonder if there is a faster solution that *doesn't* use iterators, for use with older versions of Python. I came up with: def maximum(lst): a = [] for v in lst: try: if a[0] v: a[0] = v except IndexError: a.append(v) return a[0] Of course, it's a little ugly to use a[0] instead of maxval. And I'm trying not to index a list, and here I am indexing another list. So: def maximum(lst): for v in lst: try: if maxval v: maxval = v except NameError: maxval = v return maxval And we come at last to my actual question: Is this guaranteed to work on all versions of Python? In my testing on my computer, the above function works perfectly. Even if you do this: maxval = 100 print maximum(cmp, [2, 0, 3, 1]) 3 In other words, you get a NameError in the function even if there is a global variable with that name. That's with Python 2.4, however... is this function guaranteed to work in all Python versions? I am very comfortable with the a[0] version, since I explicitly set a to an empty list, I know a[0] will always raise that IndexError. P.S. I went ahead and benchmarked the above functions, plus one more that is similar to the a[0] solution but used an empty dictionary instead of a zero-length list. I created a list of a million zeroes, and then stored a 1 at the beginning of the list. Thus the maximum functions would spend all their time iterating through values and comparing them, and very little time updating maxval or its equivalent. Times to run each function 100 times on the large list: 36.8 seconds xrange 22.3 seconds iterator 39.2 seconds IndexError on a[0] 31.5 seconds NameError with maxval 43.4 seconds KeyError on empty dictionary The conclusions I draw from these numbers: The sneaky tricks with exceptions don't bring enough speed to be worth using; two of them were actually slower than the xrange solution. Even the NameError one was only a little bit faster, and simple is better than complex, so I don't think I'd ever actually use it. The clear winner was the iterator version. It was much faster than the others, and in my opinion it is simpler and easier to understand than any of the others. -- Steve R. HastingsVita est [EMAIL PROTECTED]http://www.blarg.net/~steveha -- http://mail.python.org/mailman/listinfo/python-list
String To Dict Problem
Hi everyone. I'm trying to convert a string that looks like this:
gid = 'FPS', type = 'Label', pos = [0, 20], text = 'FPS', text2 = 'more
text without quotes', fmtline = @VALUE @SIGNAL, signals = [('FPS',
None), ('FPS2', 'something')]
to a dict that looks like this:
{'signals': [('FPS', None), ('FPS2', 'something')], 'text': 'FPS',
'pos': [0, 20], 'text2': 'more text without quotes', 'gid': 'FPS',
'type': 'Label', 'fmtline': '@VALUE @SIGNAL'}
I've got a home-rolled routine that was 'good enough', until I added
the list of tuples in there. Now it's failing. I have a hack to
'special case' it, but you know that will come up to bite me in the
future.
Does anyone have a thought on how I can turn what are basically
function keyword arguments in string form, to a dict, without using
exec or eval?
--Kamilche
--
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Re: pondering about the essence of types in python
gangesmaster wrote:
i dont think it's possible, to create proxy classes, but even if i did,
calling remote methods with a `self` that is not an instance of the
remote class would blow up.
I don't understand you here. Why can't you just do something like:
class RemoteClass(object):
... def __init__(self, name):
... self.name = name
... def __repr__(self):
... return '%s(name=%s)' % (type(self).__name__, self.name)
...
rc = RemoteClass('foo')
rc
RemoteClass(name=foo)
class ProxyClass(object):
... def __init__(self, name):
... self.remote = RemoteClass(name)
... def __repr__(self):
... return repr(self.remote)
...
pc = ProxyClass('foo')
pc
RemoteClass(name=foo)
Note that when I call methods on the remote class, I don't pass them an
instance of the proxy class -- I pass them an instance of the
appropriate, RemoteClass type. Of course my code is simplified because
I'm not actually doing something remote, but assuming things get, say,
pickled and unpickled appropriately, I'm not sure I understand why the
above won't work.
Could you give some more details?
STeVe
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Re: wired md5 hashing problem
On Sun, 2006-03-26 at 11:48 -0500, Adam DePrince wrote: What do you get when you type md5sum backup.tar.bz2? it is working. Don't know what went wrong. But now I have another question: How am I able to execute an external program, like mysqldump? I had a look into the mysql module it didn't fit my needs. -- Mit freundlichen Grüßen Matthias Güntert -- http://mail.python.org/mailman/listinfo/python-list
Re: maximum() efficency
Steve R. Hastings wrote: I was looking at a Python function to find the maximum from a list. The original was more complicated; I simplified it. The built-in max() function can replace the simplified example, but not the original. What's the original? Are you sure max can't solve it with an appropriate decorate-sort-undecorate (DSU) or the key= argument coming in Python 2.5? STeVe -- http://mail.python.org/mailman/listinfo/python-list
Re: Cookbook for beginners?
Aahz: If you were going to name three or five essential recipes from the Python Cookbook suitable for beginners, what would you pick? Yes, this is for _Python for Dummies_, so idioms that aren't in the Cookbook are also fine. Constants Static methods / Class methods Bunch TaskQueue (Queue for easy and safe multithreading) A decorator for type checking of function arguments, and/or for require/ensure, and/or for similar features of other languages that people find missing in Python. Properties and in particular lazy properties. Why and how to avoid getters/setters. Dynamically import a module (name known at runtime, may or may not be present). Unittest/doctest. -- http://mail.python.org/mailman/listinfo/python-list
Re: is mysqlsb compatible with MySQL 5.0?
Dennis Lee Bieber wrote: Check the Windows services control for MySQL and try from it... How do I do that? You might (since it sounds like this is a first attempt) need to uninstall everything -- and make sure you delete the mysql database (in case you have a garbaged root login) Ugh, if this is the case, is there more to uninstall than just using the Add/Remove programs? Where do I delete the database? -- http://mail.python.org/mailman/listinfo/python-list
Re: String To Dict Problem
Kamilche wrote:
Hi everyone. I'm trying to convert a string that looks like this:
gid = 'FPS', type = 'Label', pos = [0, 20], text = 'FPS', text2 = 'more
text without quotes', fmtline = @VALUE @SIGNAL, signals = [('FPS',
None), ('FPS2', 'something')]
to a dict that looks like this:
{'signals': [('FPS', None), ('FPS2', 'something')], 'text': 'FPS',
'pos': [0, 20], 'text2': 'more text without quotes', 'gid': 'FPS',
'type': 'Label', 'fmtline': '@VALUE @SIGNAL'}
I've got a home-rolled routine that was 'good enough', until I added
the list of tuples in there. Now it's failing. I have a hack to
'special case' it, but you know that will come up to bite me in the
future.
Does anyone have a thought on how I can turn what are basically
function keyword arguments in string form, to a dict, without using
exec or eval?
--Kamilche
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/364469
HTH
Michael
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Re: image reduction script
Kamilche, I am posting the code in another thread but am not certain that convert does anything to the picture color depth ... still searching in the doc. Philippe Kamilche wrote: To reduce the color depth of an image in PIL: im = im.convert(mode=P, palette=Image.ADAPTIVE) -- http://mail.python.org/mailman/listinfo/python-list
PIL image size reduction script
Hi, Thanks to the NG, I got the script hereunder working. 1) I am not certain that the call to convert does much (checking the doc) 2) Can this be improved as far as the final image size in (X,Y) ? For instance, passing a large .jpg with a target byte size of 7000, I get final (X,Y) results around (213, 174) ... but might want to strech it a bit while keeping the byte size. Thanks, Philippe #*** def Image_Reduce(self, p_filename, p_size): BASE_SIZE = 400.0 l_im = Image.open(p_filename) l_size = l_im.size if l_size[0] l_size[1]: l_ratio = BASE_SIZE / l_size[0] l_x_size = l_ratio * l_size[0] l_y_size = l_ratio * l_size[1] else: l_ratio = BASE_SIZE / l_size[1] l_x_size = l_ratio * l_size[0] l_y_size = l_ratio * l_size[1] #l_im.show() l_image = l_im.resize( (l_x_size, l_y_size)) l_image = l_image.convert(mode=RGB, palette=Image.ADAPTIVE) l_done = False l_tmp_file_name = 'sc_tmp_file.jpg' while False == l_done: l_image.save(l_tmp_file_name) l_st = os.stat(l_tmp_file_name) print 'HERE ', l_st if p_size l_st[6]: l_ratio -= 0.005 print 'NEW RATIO = ', l_ratio l_x_size = l_ratio * l_size[0] l_y_size = l_ratio * l_size[1] l_image = l_im.resize( (l_x_size, l_y_size)) else: l_done = True l_image.show() print l_image.size -- http://mail.python.org/mailman/listinfo/python-list
For loop and list comprehension similarity
Hi All, I apologize if this was brought up before, I couldn't find any prior art :-). On more than one occasion, I found myself wanting to use a conditional loop like this (with Invalid syntax error, of course): for i in c if test: print i*2 ...because it's similar to the list comprehension construct: [i*2 for i in c if test] - Is this the intended difference in constructs? The available equivalent feels a bit awkward: for i in c: if test: print i*2 Just curious. Thanks! Sergey. -- http://mail.python.org/mailman/listinfo/python-list
Re: SSH, remote login, and command output
Spire 01 wrote: Greetings! I'm working on a Python program for a small LAN of Linux systems running Gentoo, and I need a little help figuring out what I need to do it. So what I'd like to do is, from any given computer, log on to every other computer, run a certain command (which normally outputs text to the terminal), and store the output so I can use the aggregate statistics later in the program. I would normally something along the lines of SSH to do it, but I don't know what I would need to pull that off in Python. There's also one complication: the systems could be Gentoo systems, or they could be logged into Windows since they're dual booted. Considering all of this, can anyone give me some recommendation as to what library I should learn how to use to pull this off? I admit, I haven't done too much in the way of networks, but if someone can tell me what I need to do remote logins in this way, I'll do what I can to make it work. Thanks a million! Spire I wrote a small tool to implement cron like functionality over ssh using twisted (with public/private keys). This was written to scratch a small itch but also to learn how twisted works with conch, it's ssh module. http://crontorted-project.pollenation.net/cgi-bin/trac.cgi Feel free to use, I haven't put a license on it but it would be MIT/BSD .. contact me if you want an explicit confirmation. Tim Parkin -- http://mail.python.org/mailman/listinfo/python-list
Re: String To Dict Problem
Thanks! It's interesting, and nearly what I want, but not quite there.
When I run my sample code through it, I get a syntax error because it's
not a valid expression. If I were to put a 'dict(' in front and a ')'
at the end, THEN it nearly works - but it gives me an
'Unsafe_Source_Error: Line 1. Unsupported source construct:
compiler.ast.CallFunc' error.
How do I let one measly function in (dict), without letting them all in?
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Re: Cookbook for beginners?
Aahz a écrit :
If you were going to name three or five essential recipes from the
Python Cookbook suitable for beginners, what would you pick?
Yes, this is for _Python for Dummies_, so idioms that aren't in the
Cookbook are also fine.
1/ tuple- and dict-based dispatch, ie:
x = (result_if_false, result_if_true)[boolexpr]
y = {key1: result1, key2:result2, ...}[keyexpr]
2/ functions (and methods etc) as first-class objects (two main obvious
uses : callbacks and decorators)
+ (bonus) the combination of 1/ and 2/ !-)
3/ name-based lookups and affectations (getattr() / setattr()) and their
implementation ( __getattr__ / __setattr__)
--
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Re: maximum() efficency
Steve R. Hastings wrote: I was looking at a Python function to find the maximum from a list. The original was more complicated; I simplified it. The built-in max() function can replace the simplified example, but not the original. But you forgot to shuw us the original... [snip several implementations] Of course, it's a little ugly to use a[0] instead of maxval. And I'm trying not to index a list, and here I am indexing another list. So: def maximum(lst): for v in lst: try: if maxval v: maxval = v except NameError: maxval = v return maxval In my testing on my computer, the above function works perfectly. Even if you do this: maxval = 100 print maximum(cmp, [2, 0, 3, 1]) 3 In other words, you get a NameError in the function even if there is a global variable with that name. That's with Python 2.4, however... is this function guaranteed to work in all Python versions? Not 100% sure, but I think yes. People with longer experience in python can answer definitely. Or you can try it out yourself. The reason it works is that this: def f(): print a a=7; f() works and prints 7 (global a is used), while this def f(): print a a = 12 a=7; f() does NOT work. Python notices that a is going to get assigned to inside f and treats it as a local variable. This is also the case with your code. Try out the above examples without a=7 and notice the different error messages... The clear winner was the iterator version. It was much faster than the others, and in my opinion it is simpler and easier to understand than any of the others. I would have done it in the same way, but probably without the iterators. I.e., like this: def maximum(lst): try: m = lst[0] except (TypeError, IndexError): raise Exception Non-sequence or empty sequence given to maximum) # (you forgot the above sanity checks in your code. # not strictly necessary, but nice to have.) for x in lst: if xm: m=x return m -- http://mail.python.org/mailman/listinfo/python-list
Re: Module documentation
Tony Burrows a écrit : Just getting to grips with Python, a great language BUT With something like Java I can find the syntax of a method call with no problems, how do I do the same with Python? For example, using MySQLdb or SGMLParser I can see what the available methods are with dir, but how do I find out what parameters are needed and what they represent? In the python shell, typing 'help(symbol)' should get you started most of the time. -- http://mail.python.org/mailman/listinfo/python-list
Re: For loop and list comprehension similarity
[EMAIL PROTECTED] wrote: On more than one occasion, I found myself wanting to use a conditional loop like this (with Invalid syntax error, of course): for i in c if test: print i*2 Maybe there's been a PEP, don't really know... Currently, the only sensible alternative is what you've written below: The available equivalent feels a bit awkward: for i in c: if test: print i*2 This indeed doesn't look nice, especially if you've got lots of code instead of just print. An alternative which avoids double indentation is for i in c: if not test: continue print i*2 -- http://mail.python.org/mailman/listinfo/python-list
Re: String To Dict Problem
Kamilche wrote:
Thanks! It's interesting, and nearly what I want, but not quite there.
When I run my sample code through it, I get a syntax error because it's
not a valid expression. If I were to put a 'dict(' in front and a ')'
at the end, THEN it nearly works - but it gives me an
'Unsafe_Source_Error: Line 1. Unsupported source construct:
compiler.ast.CallFunc' error.
How do I let one measly function in (dict), without letting them all in?
You could add a Keyword node, and use it something like this:
import compiler
class SafeEval(object):
def visit(self, node,**kw):
cls = node.__class__
meth = getattr(self,'visit'+cls.__name__,self.default)
return meth(node, **kw)
def default(self, node, **kw):
for child in node.getChildNodes():
return self.visit(child, **kw)
visitExpression = default
def visitConst(self, node, **kw):
return node.value
def visitDict(self,node,**kw):
return dict([(self.visit(k),self.visit(v)) for k,v in node.items])
def visitTuple(self,node, **kw):
return tuple(self.visit(i) for i in node.nodes)
def visitList(self,node, **kw):
return [self.visit(i) for i in node.nodes]
def visitKeyword(self,node,**kw):
return node.name, self.visit(node.expr)
def safe_dict(source):
source = dict(%s) % source # funcname is actually ignored
walker = SafeEval()
ast = compiler.parse(source,eval)
kwargs = {}
args = ast.node.args
for arg in args:
if isinstance(arg, compiler.ast.Keyword):
keyword, value = walker.visit(arg)
kwargs[keyword] = value
else:
raise Exception, only keywords
return dict(**kwargs)
source= gid = 'FPS', type = 'Label', pos = [0, 20], text = 'FPS',
text2
= 'more text without quotes', fmtline = @VALUE @SIGNAL, signals =
[('FPS',None), ('FPS2', 'something')]
safe_dict(source)
{'signals': [('FPS', None), ('FPS2', 'something')], 'text2': 'more text without
quotes', 'gid': 'FPS', 'fmtline': '@VALUE @SIGNAL', 'text': 'FPS', 'type':
'Label', 'pos': [0, 20]}
Michael
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Re: object references
DrConti wrote: class ObjectClass: Test primary Key assignment if __name__ == __main__: ObjectClassInstantiated=ObjectClass() ObjectClassInstantiated.AnAttribute='First PK Elem' ObjectClassInstantiated.AnotherOne='Second PK Elem' ObjectClassInstantiated.Identifier=[] ObjectClassInstantiated.Identifier.append(ObjectClassInstantiated.AnAttribute) ObjectClassInstantiated.Identifier.append(ObjectClassInstantiated.AnotherOne) print ObjectClassInstantiated.Identifier ObjectClassInstantiated.AnAttribute='First PK Elem Changed' print ObjectClassInstantiated.Identifier leads a wrong result ./test.py ['First PK Elem', 'Second PK Elem'] ['First PK Elem', 'Second PK Elem'] -- wrong! It should write ['First PK Elem Changed', 'Second PK Elem'] i.e. the assgnment ObjectClassInstantiated.Identifier.append(ObjectClassInstantiated.AnAttribute) assigns only the attribute value, not the reference. Nono, it assigns the reference alright. In python, EVERYTHING gets assigned only a reference, .AnAttribute as well. So when you do .AnAttribute = 'Changed', you make it a reference to a NEW string 'Changed', while .Identifier[0] keeps referencing the 'First PK' string object. Strings are an unfortunate example, since they're immutable - once you create a string object, you cant't modify it any more. But if you had a more complex object, you could do .AnAttribute.changeYourself(), and .Identifier[0] would change accordingly as well, because .AnAttribute would keep pointing to the same object (albeit changed). In your case, try .AnAttribute = ['First']; .Identifier[0] = .AnAttribute; .AnAttribute[0] = 'First changed'; - this will work the way you want it to, because .AnAttribute doesn't get rebound (only the content of the object (list) it's pointing to change, but it's still the same object). -- http://mail.python.org/mailman/listinfo/python-list
Re: Cookbook for beginners?
Aahz wrote: If you were going to name three or five essential recipes from the Python Cookbook suitable for beginners, what would you pick? Yes, this is for _Python for Dummies_, so idioms that aren't in the Cookbook are also fine. If it's for _beginners_ / _dummies_, I would expect things like 1.6 names = ['George', 'Saddam', 'Osama'] name_string = ', '.join(names) 4.10 dict.setdefault(k, v) ?.? dict = dict(zip(list_a, list_b)) - listcomps 2.1 / 2.2 reading/writing from/to files ?.? string-methods like .split(), .upper(), endswith(), startswith(), isalpha() ... -- http://mail.python.org/mailman/listinfo/python-list
Re: SSH, remote login, and command output
Tim Parkin wrote: Spire 01 wrote: Greetings! ... Thanks a million! Spire I wrote a small tool to implement cron like functionality over ssh using twisted (with public/private keys). This was written to scratch a small itch but also to learn how twisted works with conch, it's ssh module. http://crontorted-project.pollenation.net/cgi-bin/trac.cgi Feel free to use, I haven't put a license on it but it would be MIT/BSD .. contact me if you want an explicit confirmation. Actually, unless you are happy to implement a BSD/MIT (or your own) license crontab parser (crontorted/crontab.py) the whole will have to be GPL? The current crontab.py is from Bothan (Thomas Herve therve doesntlike spam AT free DOT fr) if you're interested, I'll write my own crontab parser and release it. Tim Parkin -- http://mail.python.org/mailman/listinfo/python-list
Re: object references
DrConti a écrit : Dear Python developer community, I'm quite new to Python, so perhaps my question is well known and the answer too. I need a variable alias ( what in other languages you would call a pointer (c) or a reference (perl)) Well, that's the only kind of variable[1] in Python. [1] the correct name in Python is 'binding', since it's about 'binding' a reference to a name, not labelling an in-memory address and storing data there. I read some older mail articles and I found that the offcial position about that was that variable referencing wasn't implemented because it's considered bad style. There was also a suggestion to write a real problem where referencing is really needed. I have one...: You *think* you have one. I'm trying to generate dynamically class methods which works on predefined sets of object attributes. one of these is the set of attributes identfying uniquely the object (primary key). A naïve attempt to do the job: class ObjectClass: Test primary Key assignment if __name__ == __main__: ObjectClassInstantiated=ObjectClass() ObjectClassInstantiated.AnAttribute='First PK Elem' ObjectClassInstantiated.AnotherOne='Second PK Elem' ObjectClassInstantiated.Identifier=[] ObjectClassInstantiated.Identifier.append(ObjectClassInstantiated.AnAttribute) ObjectClassInstantiated.Identifier.append(ObjectClassInstantiated.AnotherOne) print ObjectClassInstantiated.Identifier ObjectClassInstantiated.AnAttribute='First PK Elem Changed' print ObjectClassInstantiated.Identifier leads a wrong result ./test.py ['First PK Elem', 'Second PK Elem'] ['First PK Elem', 'Second PK Elem'] -- wrong! It should write ['First PK Elem Changed', 'Second PK Elem'] Nope, it's exactly what you asked for !-) i.e. the assgnment ObjectClassInstantiated.Identifier.append(ObjectClassInstantiated.AnAttribute) assigns only the attribute value, not the reference. 1/ it's not an assignement 2/ it does not store the attribute value, it stores the reference to the object the attribute is bound to. When you later rebind the attribute, it only impact this binding - there's no reason it should impact other bindings. so my question is: is it still true that there is no possibilty to get directly object references? But object references *are* what you have. Is there a solution for the problem above ? Yes : keep a reference to the attribute name, not to the value bound to that name. There are many ways to do it, here's one: ObjectClass.Identifier = property( fget=lambda self: [self.AnAttribute, self.AnotherOne] ) and here's another one: ObjectClassInstantiated._identifier_parts = [] # note the use of strings, not symbols ObjectClassInstantiated._identifier_parts.append(AnAttribute) ObjectClassInstantiated._identifier_parts.append(AnotherOne) ObjectClass.Identifier = property( fget=lambda self: [getattr(self, name) \ for name in self._identifier_parts] ) Thank you for any feedback May I add some ? Your naming conventions are highly unpythonic. We usually use CamelCase for classes names, and (in order of preference) all_lower_with_underscores or mixedCaps for variables/attributes/functions etc. HTH -- http://mail.python.org/mailman/listinfo/python-list
Re: String To Dict Problem
Ah, finally, that's exactly what I need! Thanks bunches. I was attempting to modify your first code to fit my needs, but mine was much longer, and not yet working, a sure clue that yours is a better solution. :-D -- http://mail.python.org/mailman/listinfo/python-list
Re: Accessing func_name from inside a function
Alex Martelli wrote: Personally, I'd rather have a 3.0 keyword referring to the current object (module for module toplevel code, class for classbody toplevel code, function for code within a function) -- say for the sake of argument the keyword is 'current'; this would allow current.__name__ to have the obvious meaning, and would also allow a few more neat things (such as natural access to current.__doc__). That was my thought too, that what is really desired is a *obvious* way to get a dependable reference to the current function as you describe here. A quick experiment... with an obvious result: def foo(): print foo.__name__ ... foo() foo boo = foo boo() foo boo.__name__ 'foo' foo = None boo() Traceback (most recent call last): File stdin, line 1, in ? File stdin, line 1, in foo AttributeError: 'NoneType' object has no attribute '__name__' A Current key word would fix this. Or possibly This which would be short for This object. This may also relate to suggestions to reduce the need for having self in the argument list of methods. So if a keyword This could mean this method or function, then Self could mean this class. Hmmm, methods that use Self in this way might run into problems, but I havn't had enough coffee to think it though. ;-) Cheers, Ron -- http://mail.python.org/mailman/listinfo/python-list
Re: MVC in Python for web app dev
[EMAIL PROTECTED] a écrit : Thanks Rune. I've already checked out Django and TG and have found both the projects to be a little misguided. I think the one great thing they have over Rails is the use of SQLObject Then you haven't really checked Django - it doesn't use SQLObject. Having said that, neither TG or Django seem to have the learning material available on an equivilent standard to Rails. I found Django's doc to be mostly good, even if a bit terse on some points (but then there's the mailing-list). Maybe it's just because they're more immature and thus Rails has got the head start here. Django has been 'extracted' from existing software (3+ years of use in production), so I wouldn't call it 'immature'. It certainly has warts (the most obvious one - the ORM - will be fixed in 0.92, that is in few weeks), but I found it mostly usable, and (this ORM issue apart, but transition should not be a big issue) stable enough to start using it on real-life projects. I guess more than pointing out a few URLs I was looking for some peoples honest opinion on why they would chose one over the other (besides the basis of language alone). Well, the 'language' criteria is already enough for me. Ruby is fine too, but I've already been programming in Python for 5+ years - talking about 'head start' !-) I'm just trying to source the most viable option at the moment, trying to find something to offer quickly without resorting to *shudders* Spring or the like. -- http://mail.python.org/mailman/listinfo/python-list
Re: New development windows, IronPython or PythonWin
[EMAIL PROTECTED] a écrit : Dan wrote: I realise its in beta. But long term, do you think that the win32com, win32gui etc... will have no support because everyone jumps on the Microsoft bandwagon? Aren't the windows support extensions supported primarily by one guy, Mark Hammond? As a developer, this seams to leave me with a vulnerability long term. Thanks for the advise. Bruno Desthuilliers wrote: Well, from what we've seen so far, I'd rather rely on open source software than on proprietary one. An oss project lives as long as someone is willing to maintain it, and anyone can pick it up. And I wouldn't count on every one jumping on MS wagon neither. I find this comment curious, as IronPython *is* an open source software. based on a proprietary runtime (yes, I know, Mono... but there again, there are legal issues to consider). And what will happen when MS discontinue dotnet ??? -- http://mail.python.org/mailman/listinfo/python-list
[ANN] Firedrop 0.2.0 - The Python Blog Client
It has finally happened, the release of `Firedrop 0.2.0 http://www.voidspace.org.uk/python/firedrop2/`_. The impatient can download the new release here : `Firedrop 0.2.0 (1.3mb) http://www.voidspace.org.uk/cgi-bin/voidspace/downman.py?file=firedrop2-0.2.0.zip`_ .. note:: The first time you run version 0.2.0 it will convert your weblog config file to the new format. **Firedrop2** is the Python blog client with a host of features. These include : * RSS feed generation * Categories * Automatic archive generation * A powerful set of plugins, including spell checker and emailer * Entries can be made in text, HTML, ReST, textile, sextile or markdown markup * HTML templating system and macros for all sorts of tricks * Built in FTP capability for uploading your blog to a server * Because it's written in Python, it is easy to extend Firedrop or create new plugins for it This new release has been made possible by the hard work of `Stewart Midwinter http://www.midtoad.org`_. The changes and new features include : * Firedrop will now start up by opening a default site. * You can set the default site using the GUI. * Main file name changed to ``firedrop.pyw`` * `ConfigObj http://www.voidspace.org.uk/python/configobj.html`_ is now used to edit all the config files. * Full support for all style elements (e.g. underline, bold) in four major markup formats: ReST, Sextile, Textile, Markdown (plus HTML). * New entries are created in a separate dialog that takes care of the markup. * Links are available to websites for the markup styles. * You can reset the app to a null site, and/or delete all entries. * You can force a full build of your site, or just update your site. * You can now create sites serving Article Collections or Items Lists (e.g. FAQs) in addition to Weblogs. * Firedrop2 now runs on Mac OS X and Linux in addition to Windows. * You can view logfile contents using the GUI. * Documentation has been updated to reflect these changes. There is a roadmap for future releases on the `Firedrop2 Trac Site http://firedrop2.python-hosting.com`_. -- http://mail.python.org/mailman/listinfo/python-list
Re: For loop and list comprehension similarity
Thank you for replying, Mitja! That *is* a nice alternative. Do you think it's a good idea to ask on comp.python.devel if they would be interested in a PEP about this (provided there is none)? Cheers, Sergey. -- http://mail.python.org/mailman/listinfo/python-list
Re: image reduction script
Be sure and use mode = P instead of RGB, like you have in your other code. P is for palettized images. Don't palettize if you're storing as JPG, only if you're storing as PNG or some other format that can handle 256 color images. -- http://mail.python.org/mailman/listinfo/python-list
Advice for Python and Web Server/Services?
I have recently discovered Python and like it quite a bit. I would like to use it on a new project I am starting. The project will gather data from several web services and present the collected data to browser users through a web server. So basically I need a full-time web server and a separate way to poll web services for their data. There is no database involved. The problem is that I have tried several Python web servers (CherryPy, Karrigell, etc) and they all have problems getting out through my Comcast cable modem. There is a 3 second pause every 10th file. Never the 9th or 11th, but always the 10th file. I thought maybe Comcast was limiting incomming HTTP but Apache does not do this so I'm stumped as to why it is happening with the Python servers. All servers work fine over the LAN. Anyway, I wanted to get some advice on what type of setup would be best for this using Apache. The web service polling needs to be going all the time so a straight CGI-type thing is not an option. I've looked in to fastcgi and mod_python but I'm not sure either is what I need. What I want is for my Python program to be polling the web services 24/7 and Apache to serve static pages by itself but call a function in my already running Python program for files with a certain extension (.xml for example). Have any of you done something like this before? Ideally, I'd like to figure out why the Python servers are having problems. This is a very low volume system so straight Python would be great if I can get it working. Thanks for any advice you can give. -- Ron Davis -- Ron Davis -- http://mail.python.org/mailman/listinfo/python-list
wildcard exclusion in cartesian products
The python code below is adapted from a Haskell program written by Tomasz Wielonka on the comp.lang.functional group. It's more verbose than his since I wanted to make sure I got it right. http://groups.google.com/group/comp.lang.functional/browse_frm/thread... Does anyone know how to turn it into a module (or whatever it's called) so that I can put it in a loop and not have to generate the whole list? I've already tried without success. The program solves the following problem: generate the subset X of the cartesian product S^n that excludes n-tuples defined by wildcards. For example, if I want to exclude from [1,2,3]^3 the wc's [1,*,2] and [*,3,*,3,*], where * stands for a sequence of zero or more elements of [1,2,3], then I just type for x in generateNotMatching([1,2,3,4],4,[[1,'*',2],[3,'*',4]]): print x and get the output [1, 1, 1] [1, 1, 3] [1, 2, 1] [1, 2, 3] [1, 3, 1] [2, 1, 1] [2, 1, 2] [2, 1, 3] [2, 2, 1] [2, 2, 2] [2, 2, 3] [2, 3, 1] [2, 3, 2] [3, 1, 1] [3, 1, 2] [3, 2, 1] [3, 2, 2] This is nice! But all elements are generated before they are printed. ## import sys, os, string def imap(function, source): for element in source: yield function(element) def any(iterable): '''True iff at least one element of the iterable is True''' for element in iterable: if element: return True # or element and change the definition return False def all(iterable): '''True iff no element of the iterable is True''' '''SHOULD BE?: True iff all element of the iterable are True''' for element in iterable: if not element: return False return True def rev(L): rL=[] for x in L: rL=[x]+rL return rL def advancePattern(x,p): if p==[]: return [] else: h=p[0] t=p[1:] if h != '*': if h == x: return [t] else: return [] else: return [p] + [t] + advancePattern(x,t) def advancePatterns(x,P): aP=[] for p in P: aP += advancePattern(x,p) return aP #return [advancePattern(x,p) for p in P] def allStar(p): return all( imap((lambda x: x=='*'),p) ) def notNullOrZero(p,n): return p !=[] or n==0 def generateNotMatching(A,n,P): return gen(A,n,P,[]) def gen(A,n,P,acc): if any(imap((lambda p: allStar(p) and notNullOrZero(p,n)), P)): return [] else: if n==0: return map(rev,[acc]) else: aG=[] for a in A: aG += gen(A,n-1,advancePatterns(a,P),[a]+acc) return aG ## -- http://mail.python.org/mailman/listinfo/python-list
Re: Python types
Salvatore a écrit : Thank's everybody :-) Here is a type définition I've found on the net which I agree with : Attribute of a variable which determines the set of the values this variabe can take and the operations we can apply on it. Then - as already pointed by Alex - there is no type in Python, since there is no variable (even if this term is often improperly used for bindings) !-) Ok, let's s/variable/object/g and define some objects and operations: def myop(obj): return obj.foo * 2 class Bar(object): pass b = Bar() Can we apply the myop() operation on the object name 'b' is bound to ? myop(b) Traceback (most recent call last): File stdin, line 1, in ? File stdin, line 1, in myop AttributeError: 'Bar' object has no attribute 'foo' Well... but wait a minute: b.foo = [] myop(b) - [] Err... Wait another minute: b2 = Bar() type(b) is type(b2) - True myop(b2) Traceback (most recent call last): File stdin, line 1, in ? File stdin, line 1, in myop AttributeError: 'Bar' object has no attribute 'foo' Ok, so even if Python itself declares b and b2 (read: objects that names b and b2 are bound to) to be of the same type, you cannot apply the myop() operation on b2... Also: del b.foo myop(b) Traceback (most recent call last): File stdin, line 1, in ? File stdin, line 1, in myop AttributeError: 'Bar' object has no attribute 'foo' So *sometimes* you can apply myop() to b, and sometimes you can't. Now if we come back to your original post: All objects seem to have a perfectly defined type Perfectly defined ? Really ? Not for your current definition of 'type' at least !-) I still mostly agree with the given definition of type. But the fact is that in Python, the type*s* of an object are not so perfectly defined - they're mostly implicits, and can vary during the object's lifetime. Note that it does'nt make Python weakly typed - you cannot perform any arbitrary operation on a given object, only the operations this object can support at a given moment. FWIW, if you want a weakly typed language, take a look at C. -- http://mail.python.org/mailman/listinfo/python-list
Python multithreading problem
//A CRAWLER IMPLEMENTATION please run this prog. on the shell and under the control of debugger when this prog. is run normally the prog. does not terminate .It doesn't come out of the cond. if c5: so this prog. continues infinitely but if this prog is run under the control of debugger the prog terminates when the cond. if c5: becomes false i think this prob. may be due to multithreading pls help. from sgmllib import SGMLParser import threading import re import urllib import pdb import time class urlist(SGMLParser): def reset(self): SGMLParser.reset(self) self.list=[] def start_a(self,attr): href=[v for k,v in attr if k==href] if href: self.list.extend(href) mid=2 c=0 class mythread(threading.Thread): stdmutex=threading.Lock() global threads threads=[] def __init__(self,u,myid): self.u=u self.myid=myid threading.Thread.__init__(self) def run(self): global c global mid if c5: self.stdmutex.acquire() self.usock=urllib.urlopen(self.u) self.p=urlist() self.s=self.usock.read() self.p.feed(self.s) self.usock.close() self.p.close() c=c+1 fname=/root/ + str(c) + .txt self.f=open(fname,w) self.f.write(self.s) self.f.close() print c print self.p.list print self.u print self.myid for j in self.p.list: k=re.search(^https?:,j) if k: i=mythread(j,mid) i.start() threads.append(i) mid=mid+1 self.stdmutex.release() if __name__==__main__: thread=mythread(http://www.google.co.in/,1) thread.start() threads.append(thread) for thread in threads: thread.join() print main thread exits -- http://mail.python.org/mailman/listinfo/python-list
Re: wired md5 hashing problem
Matthias Güntert [EMAIL PROTECTED] writes: i am in the process of writing a python script to backup my data. Now I would like to implement md5/sha1 hashes. Try editing as follows: change f = open(fname, rb) while 1: block = f.read(1024*1024) if not block: break # generate the hash m.update(block) f.close() to: f = open(fname, rb) nbytes = 0 while 1: block = f.read(1024*1024) nbytes += len(block) if not block: break # generate the hash m.update(block) f.close() print '%d bytes processed' As Adam DePrince noticed, the md5 checksum you generated was that of an empty file. So the above should tell you whether you're actually processing any input; if you don't get the expected number of bytes, debug from there. -- http://mail.python.org/mailman/listinfo/python-list
Re: Accessing func_name from inside a function
James Thiele a écrit : I'd like to access the name of a function from inside the function. My first idea didn't work. def foo(): ... print func_name ... foo() Traceback (most recent call last): File stdin, line 1, in ? File stdin, line 2, in foo NameError: global name 'func_name' is not defined My second attempt works but looks ugly. def foo(): ... import inspect ... print inspect.stack()[0][3] ... foo() foo Is there a standard way of getting the name of a function from inside the function? You've already got good answers. Now here's another workaround: class _FooFunction(object): def __call__(self): print self.__class__.__name__ foo = _FooFunction() -- http://mail.python.org/mailman/listinfo/python-list
Re: image reduction script
Kamilche wrote:
Be sure and use mode = P instead of RGB, like you have in your other
code. P is for palettized images. Don't palettize if you're storing as
JPG, only if you're storing as PNG or some other format that can handle
256 color images.
My problem is this:
1) If I use a save to jpg after a convert('P') I get an exception (what you
are refering to I assume)
2) If I use a save to png (I start with a jpg), then the (X,Y) size of the
output is much smaller than convert('RGB') and save to jpg - (and I want to
opposit: as small as possible in byte size and as large as possible in
(X,Y) ):
*** SAME INPUT FILE.JPG ***
***convert('P') save to PNG
/home/philippe/tmp/tmprpdfEO is a 65x87 Raw PPM image with 256 levels
Default gamma for ITRUE image is 1.00
Building XImage...done
Have adjusted image from 1.00 to display gamma of 2.20
Versus:
***convert('RGB') save to JPG
/home/philippe/tmp/tmpYCLrQR is a 173x231 Raw PPM image with 256 levels
Default gamma for ITRUE image is 1.00
Building XImage...done
Have adjusted image from 1.00 to display gamma of 2.20
Philippe
--
http://mail.python.org/mailman/listinfo/python-list
Re: maximum() efficency
Steve R. Hastings [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] I was looking at a Python function to find the maximum from a list. The original was more complicated; I simplified it. The built-in max() function can replace the simplified example, but not the original. If you are interested in both the min and max values, here is an algorithm that performs only 3 comparisons for every 2 list items, instead of the brute force method's 4 comparisons. This walks the input list in pairs, compares the two items to each other, then compares the lesser with the current min and the greater with the current max. def minMax(L): lenL = len(L) if lenL == 0: return None,None if lenL == 1: return L[0],L[0] min_ = max_ = L[0] if lenL % 2: i = 1 else: i = 0 while i lenL: a,b = L[i],L[i+1] if a b: a,b = b,a if a min_: min_ = a if b max_: max_ = b i += 2 return min_,max_ Of course, this much Python bytecode is not near as fast as simply calling the builtins min() and max(). But, if you add psyco to the mix, things aren't so cut-and-dried. I tested this method using a list of randomly-generated strings, and after the list length exceeds 100-500 or so, minMax starts to outperform the compiled min() and max(). The following table shows the timing for the brute force min() and max() calls, followed by minMax(): List length 1: 0.229 0.612 List length 2: 0.056 0.0001081 List length 10: 0.059 0.707 List length100: 0.154 0.087 List length500: 0.589 0.534 List length 1000: 0.0001176 0.670 List length 1: 0.0011485 0.0008954 List length 10: 0.0126720 0.0077379 Using the OP's test of 1 million zeros with the first zero changed to a 1, here is the performance of minMax vs. min() and max(): List length 100: 0.1235953 0.0126896 minMax is 10X faster! Ironically, it's faster calling minMax() than either min() or max(). If your list contains objects that are expensive to compare, the crossover list length may be much shorter. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Accessing func_name from inside a function
Ron Adam [EMAIL PROTECTED] wrote: A Current key word would fix this. Or possibly This which would be short for This object. I think This would cause huge confusion, since in other popular language the keyword this means (a pointer/reference to) the instance variable on which the method is being called -- my use is instead for the object of the immediate lexically enclosing scope (a module, class, or function). Implementation wouldn't be trivial in today's CPython, anyway: frames have no references at all to function objects (only to _code_ objects), and class objects don't even exist untill well after their top-level code has long finished running; to make Current possible, these subtle points of semantics would have to be changed in quite a revolutionary way, especially where classes are concerned. Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: For loop and list comprehension similarity
On 2006-03-26, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hi All, I apologize if this was brought up before, I couldn't find any prior art :-). On more than one occasion, I found myself wanting to use a conditional loop like this (with Invalid syntax error, of course): for i in c if test: print i*2 ...because it's similar to the list comprehension construct: [i*2 for i in c if test] - Is this the intended difference in constructs? The available equivalent feels a bit awkward: for i in c: if test: print i*2 for j in [i*2 for i in c if test]: print j -- Grant Edwards grante Yow! .. I wonder if I at ought to tell them about my visi.comPREVIOUS LIFE as a COMPLETE STRANGER? -- http://mail.python.org/mailman/listinfo/python-list
Re: Accessing func_name from inside a function
James Thiele [EMAIL PROTECTED] wrote: I'd like to access the name of a function from inside the function. My first idea didn't work. def foo(): ... print func_name ... foo() Traceback (most recent call last): File stdin, line 1, in ? File stdin, line 2, in foo NameError: global name 'func_name' is not defined So, define it -- as a function, of course: def func_name(): import sys return sys._getframe(1).f_code.co_name def foo(): print func_name() def bar(): print func_name() No doubt you'll object that the internals of func_name are ugly, but the point is that it can be hidden anywhere you like, so its internals are as irrelevant as they would be if it was a built-in. Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: Accessing func_name from inside a function
Steven D'Aprano wrote: On Sun, 26 Mar 2006 10:19:36 +1000, Ben Finney wrote: James Thiele [EMAIL PROTECTED] writes: I'd like to access the name of a function from inside the function. A function, like most other objects in Python, can have any number of names bound to it without the object being informed. Any of those names can then be used to reference the object, and the object has no way of knowing by what name it was referenced. Because of this fallacy, You keep using that word. I do not think it means what you think it means. *wink* it's generally considered bad programming style to want to know the name of the current object from inside that object. I agree whole-heartedly with Ben's sentiments here, although I can also point out by example why it might be useful for a function to know it's own name: def Ackermann(i, j): Returns the Ackermann function of integers i and j. The Ackermann function is an example of a function which grows at a much faster than exponential rate. Ackermann(i, j) for i 2 grows even more quickly than 2**2**2**...**2 (where there are j exponents). It is an example of a recursive function which is not primitively recursive and was discovered by the German mathematician Wilhelm Ackermann in 1928. Ackermann(1, 1) 2 Ackermann(2, 2) 16 Ackermann(2, 3) 65536 The Ackermann function is not defined for i,j = 0. See http://en.wikipedia.org/wiki/Ackermann_function and 'Introduction to Algorithms' by Thomas H Cormen, Charles E Leiserson, Ronald L Rivest, pp. 451-453. if i 0 or j 0: raise ValueError( arguments to the Ackermann function must be positive) if i == 1: return 2**j if j == 1: return Ackermann(i-1, 2) return Ackermann(i-1, Ackermann(i, j-1)) Notice that if you change the name of the function, you have to change it in no less than three places in the function definition and four places in the __doc__ string, but a global search and replace is too greedy and will change too much. As a general principle, it is considered best practice to code in such a way that if you change something, you only need to change it in one place. I guess that the Original Poster wants some magic that allows functions to do this: def Ackermann(i, j): Returns the Ackermann function of integers i and j. The Ackermann function is an example of a function which grows at a much faster than exponential rate. %MAGIC(i, j) for i 2 grows even more quickly than 2**2**2**...**2 (where there are j exponents). It is an example of a recursive function which is not primitively recursive and was discovered by the German mathematician Wilhelm Ackermann in 1928. %MAGIC(1, 1) 2 %MAGIC(2, 2) 16 %MAGIC(2, 3) 65536 The Ackermann function is not defined for i,j = 0. See http://en.wikipedia.org/wiki/Ackermann_function and 'Introduction to Algorithms' by Thomas H Cormen, Charles E Leiserson, Ronald L Rivest, pp. 451-453. if i 0 or j 0: raise ValueError( arguments to the Ackermann function must be positive) if i == 1: return 2**j if j == 1: return %MAGIC(i-1, 2) return %MAGIC(i-1, %MAGIC(i, j-1)) Another possibility would be: def recursive_func(func): def new_func(*args, **kw): return func(new_func, *args, **kw) return new_func @recursive_func def Ackermann(recurse, i, j): # yadda yadda recurse(i-1, ...), recurse(y-2, ...) Now he can easily rename Ackermann to Ack and need only make the change in one place. I suspect that the correct solution to the O.P.'s problem is to think carefully about the names of your functions in advance. By the way, the real problem here is referencing by name, rather than using true references. Which is the result of using a textual language. The real solution would be to store real-references to the function and only present the name in a graphical interface. -- http://mail.python.org/mailman/listinfo/python-list
Re: wildcard exclusion in cartesian products
[EMAIL PROTECTED] wrote: The python code below is adapted from a Haskell program written by Tomasz Wielonka on the comp.lang.functional group. It's more verbose than his since I wanted to make sure I got it right. http://groups.google.com/group/comp.lang.functional/browse_frm/thread... Does anyone know how to turn it into a module (or whatever it's called) so that I can put it in a loop and not have to generate the whole list? I've already tried without success. I know next to nothing about Haskell, but I believe that it evaluates sequences lazily by default. Python can certainly do lazy evaluation, but you'll have to ask for it explicitly. The program solves the following problem: generate the subset X of the cartesian product S^n that excludes n-tuples defined by wildcards. For example, if I want to exclude from [1,2,3]^3 the wc's [1,*,2] and [*,3,*,3,*], where * stands for a sequence of zero or more elements of [1,2,3], then I just type [I think your example and test case may have become mixed up] ... Here's an iterative lazy solution. While we're at it, why not use re for pattern matching, rather than rolling our own matcher (this does restrict the set members to characters, maybe that's OK): import re def cp_excl_wc(alpha, N, *exclusions): RE0, RE1 = compile_re(exclusions) def add_one(outer, RE_PATTS): if RE_PATTS: for partial in outer: for a in alpha: next = partial + a if not RE_PATTS.match(next): yield next else: # if there's no pattern to match at this length # don't waste time trying for partial in outer: for a in alpha: yield partial+a cpgen = , # RE0 holds the patterns that match at the beginning, so are tested # against all iterations less than full length for n in range(N-1): cpgen = add_one(cpgen, RE0) # For the last place, test the full-length patterns cpgen = add_one(cpgen, RE1) return cpgen def compile_re(exclusions): re0 = [] # patterns that can be matched anywhere re1 = [] # patterns that match only the full-length for pattern in exclusions: pattern = pattern.replace(*, .*) if pattern.endswith(.*): re0.append(pattern) re1.append(pattern+$) re0 = re0 and re.compile(|.join(re0)) or None re1 = re1 and re.compile(|.join(re1)) or None return re0, re1 nm = cp_excl_wc(123,3,1*2,3*1) nm.next() '111' nm.next() '113' nm.next() '121' nm.next() '123' list(nm) ['131', '133', '211', '212', '213', '221', '222', '223', '231', '232', '233', '312', '313', '322', '323', '332', '333'] Is this the sort of thing you had in mind? Michael -- http://mail.python.org/mailman/listinfo/python-list
Re: Python types
Thank's Bruno. -- http://mail.python.org/mailman/listinfo/python-list
Re: wildcard exclusion in cartesian products
Michael, Yes! That is precisely what I had in mind! Thanks, Walter Kehowski -- http://mail.python.org/mailman/listinfo/python-list
Re: MVC in Python for web app dev
http://www.myghty.org/ That one is excellent. Robert -- http://mail.python.org/mailman/listinfo/python-list
regimes
Collecter rapidement les informations nécessaires pour travailler de chez soi avec son ordinateur et de ce fait amasser rapidement des rentrées d'argents plus qu'honorables To collect the necessary information quickly for to work of at home with your computer and of that made accumulate quickly of the returns of money more that honorable contact: [EMAIL PROTECTED] http://www.allsolutionsnetwork.com/RN/RN32579 http://10perday.com/?ref=5113 This message was sent with NNTP Scribbler (www.e-advertize.com). -- http://mail.python.org/mailman/listinfo/python-list
Re: What's The Best Editor for python
On 2006-03-26, Andrew Gwozdziewycz [EMAIL PROTECTED] wrote: If you want something that won't get in your way, you should really use /bin/ed. It's probably simpler to use then searching the archives. /bin/ed will also run in cygwin for windows. Can one of you say to me what's the best editor for editing the python programs( for linux or windows ) The best editor is the one you like best. I'm a vim user with taglist--I'm not fully happy with how ctags does Python, but it's more than Good Enough. But editors are religious, and not worth arguing about, generally. -- http://mail.python.org/mailman/listinfo/python-list
Re: New development windows, IronPython or PythonWin
[EMAIL PROTECTED] wrote: IronPython is currently nowhere near production quality. I would not recommend it. I know at least one firm developing production quality software using IronPython, so your statement 'nowhere near' is a bit off. They're pretty close to a full Python 2.4 implementation , and the list of bugs shrinks daily. It's not a project that's about to disappear either. Fuzzyman http://www.voidspace.org.uk/python/index.shtml -- http://mail.python.org/mailman/listinfo/python-list
Re: For loop and list comprehension similarity
[EMAIL PROTECTED] writes: On more than one occasion, I found myself wanting to use a conditional loop like this (with Invalid syntax error, of course): for i in c if test: print i*2 ...because it's similar to the list comprehension construct: [i*2 for i in c if test] Why not combine the two: for i in [j for j in c if test]: print i*2 -- \ I got food poisoning today. I don't know when I'll use it. | `\ -- Steven Wright | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
interactive programme (add a new line in Tk)
somebody recently showed me how to create a new line using \n which was great.The thing is when i am creating the programme the text i wish to add is quite long.and it ends up stretching the width of several pages,which i think looks quite messy.Would it be possible for some one to show me how to create another line while writing my programme.What i mean by this is where my text ends iv arrivedi wish to add a new line beneath to continue my text so i do not reach the end of the page. from Tkinter import * root = Tk() w = Label(root, text=\n Hello, world! \n iv arrived) w.pack() root.mainloop() Thanks nige -- http://mail.python.org/mailman/listinfo/python-list
Re: Accessing func_name from inside a function
Alex Martelli wrote: Ron Adam [EMAIL PROTECTED] wrote: A Current key word would fix this. Or possibly This which would be short for This object. I think This would cause huge confusion, since in other popular language the keyword this means (a pointer/reference to) the instance variable on which the method is being called -- my use is instead for the object of the immediate lexically enclosing scope (a module, class, or function). Implementation wouldn't be trivial in today's CPython, anyway: frames have no references at all to function objects (only to _code_ objects), and class objects don't even exist untill well after their top-level code has long finished running; to make Current possible, these subtle points of semantics would have to be changed in quite a revolutionary way, especially where classes are concerned. Alex Yes, I figured it would not be an easy or simple addition. An easier alternative might be to be able to limit specific name rebindings. Then some names could be depended on to always point to a specific object. Something like that would need to be used sparingly I think. Cheers, Ron -- http://mail.python.org/mailman/listinfo/python-list
work at home
Collecter rapidement les informations nécessaires pour travailler de chez soi avec son ordinateur et de ce fait amasser rapidement des rentrées d'argents plus qu'honorables To collect the necessary information quickly for to work of at home with your computer and of that made accumulate quickly of the returns of money more that honorable contact: [EMAIL PROTECTED] http://www.allsolutionsnetwork.com/RN/RN32579 http://10perday.com/?ref=5113 This message was sent with NNTP Scribbler (www.e-advertize.com). -- http://mail.python.org/mailman/listinfo/python-list
Re: Bitwise OR?
Adam DePrince wrote:
BTW: Is there something like a sizeof() method for int numbers?
import struct
help( strict.calcsize )
Mh, that doesn't do what i want. I'd like to have something like:
def size(number):
return sizeof(number)
Why one bit at a time?
Good question...
Here my new approach based on your idea:
_digits = { 0:, 1:1000, 2:0100, 3:1100,
4:0010, 5:1010, 6:0110, 7:1110,
8:0001, 9:1001, 0xa:0101, 0xb:1101,
0xc:0011, 0xd:1011, 0xe:0111, 0xf:}
def bitstring2(number):
lsb--msb
rlist = list()
if number = 0:
while number:
rlist.append( _digits[number 0xF] )
number = 4
else:
while number != -1:
rlist.append( _digits[number 0xF] )
number = 4
return ''.join(rlist)
This was faster for positive numbers. For negative numbers yours was
faster, but my version handles those numbers different.
Your version fails for Large numbers since hex( long ) returns
something like 0xFFFL instead of 0xfff.
Cheers - Adam
Cheers :)
- eth
--
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PyPy is now able to compile efficient extension modules!
PyPy is now able to compile efficient extension modules!. This was recently announced by Christian Tismer on Pypy's mailing list. To learn more: http://codespeak.net/pipermail/pypy-dev/2006q1/002911.html -- http://mail.python.org/mailman/listinfo/python-list
Re: For loop and list comprehension similarity
Why not combine the two: I guess because (at least in source code) you're doing a loop twice :-). I don't know what a compiler would do. I think though that the for i in c if test: construct is more readable and maybe can even be better optimized. Thanks! Sergey. -- http://mail.python.org/mailman/listinfo/python-list
Re: For loop and list comprehension similarity
Rather than a list comprehension, it would be faster and more memory-efficient to use a generator comprehension. Just change the square brackets to parentheses: for j in (i*2 for i in c if test): print j Grant Edwards wrote: On 2006-03-26, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hi All, I apologize if this was brought up before, I couldn't find any prior art :-). On more than one occasion, I found myself wanting to use a conditional loop like this (with Invalid syntax error, of course): for i in c if test: print i*2 ...because it's similar to the list comprehension construct: [i*2 for i in c if test] - Is this the intended difference in constructs? The available equivalent feels a bit awkward: for i in c: if test: print i*2 for j in [i*2 for i in c if test]: print j -- http://mail.python.org/mailman/listinfo/python-list
Re: Python multithreading problem
abhinav wrote: //A CRAWLER IMPLEMENTATION please run this prog. on the shell and under the control of debugger when this prog. is run normally the prog. does not terminate .It doesn't come out of the cond. if c5: so this prog. continues infinitely How do you know? Have you waited *infinitely* ;) if c5: self.stdmutex.acquire() The problem you have a lot of threads that has already checked c 5 condition but has not acquired the lock yet. Besides you have another problem: if a thread raises an exception you don't release the lock. Why don't you use Queue module for sane thread management? Serge. -- http://mail.python.org/mailman/listinfo/python-list
Re: py web-app-frameworks without a rdbms...
On Wednesday 22 March 2006 02:06, [EMAIL PROTECTED] wrote: Hi folks, Of TurboGers Django WAF candidates, which one would be easier to use in an environment where the data/content doesn't come an RDBMS, but from other server-side apps... If these are not good candidates, could you suggest appropriate ones... TIA, /venkat Be sure to have a look at CherryPy: http://www.cherrypy.org Michael. -- http://mail.python.org/mailman/listinfo/python-list
Re: maximum() efficency
On Sun, 26 Mar 2006 20:34:28 +0200, Mitja Trampus wrote: I would have done it in the same way, but probably without the iterators. I.e., like this: def maximum(lst): try: m = lst[0] except (TypeError, IndexError): raise Exception Non-sequence or empty sequence given to maximum) # (you forgot the above sanity checks in your code. # not strictly necessary, but nice to have.) for x in lst: if xm: m=x return m I left out the original sanity check, because I just wanted a streamlined simple example. I had a nagging feeling that I was missing something simple, and you have put your finger on it. That's perfect! It's simple, it's clear, and it will work on any version of Python. Thanks! -- Steve R. HastingsVita est [EMAIL PROTECTED]http://www.blarg.net/~steveha -- http://mail.python.org/mailman/listinfo/python-list
Python float representation error?
try running this in python: print [39.95] the output i get is: [39.953] what's up with that? -- http://mail.python.org/mailman/listinfo/python-list
Re: [ANN] Firedrop 0.2.0 - The Python Blog Client
Fuzzyman wrote: It has finally happened, the release of `Firedrop 0.2.0 * `ConfigObj http://www.voidspace.org.uk/python/configobj.html`_ is now used to edit all the config files. You should add this to the dependency list in the install page, it tripped me up. Kent -- http://mail.python.org/mailman/listinfo/python-list
Re: maximum() efficency
On Sun, 26 Mar 2006 10:34:16 -0700, Steven Bethard wrote: What's the original? def minimum(cmp, lst): minimum(cmp, lst) Returns the minimal element in non-empty list LST with elements compared via CMP() which should return values with the same semantics as Python's cmp(). If there are several minimal elements, the last one is returned. if not lst: raise ValueError, 'empty list' minval = lst[0] for i in xrange(1, len(lst)): v = lst[i] if cmp(minval, v) 0: minval = v return minval This is from Google's goopy package. http://goog-goopy.sourceforge.net/ -- Steve R. HastingsVita est [EMAIL PROTECTED]http://www.blarg.net/~steveha -- http://mail.python.org/mailman/listinfo/python-list
Re: What's the best way to learn perl for a python programmer?
The online docs are very good. Just run perldoc perl, and then go through the various tutorial pages (starting with perldoc perlintro). You can also read them online here: http://perldoc.perl.org/perl.html . Then go to http://www.perlmonks.org . They have many tutorial-style articles there, as well as a very helpful and knowledgeable community. If you absolutely need to write object-oriented Perl, you probably want to keep things as simple as possible and just use regular old hash-based objects. Writing OO Perl code is a whole nuther ball of wax than just writing procedural Perl code. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python float representation error?
[EMAIL PROTECTED] wrote: try running this in python: print [39.95] the output i get is: [39.953] what's up with that? This comes from the imprecision in representing base-10 fractions as binary. Try print [str(39.95)]. If you want to print a list, maybe: print map(str, alist) James -- James Stroud UCLA-DOE Institute for Genomics and Proteomics Box 951570 Los Angeles, CA 90095 http://www.jamesstroud.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: interactive programme (add a new line in Tk)
nigel wrote: somebody recently showed me how to create a new line using \n which was great.The thing is when i am creating the programme the text i wish to add is quite long.and it ends up stretching the width of several pages,which i think looks quite messy.Would it be possible for some one to show me how to create another line while writing my programme.What i mean by this is where my text ends iv arrivedi wish to add a new line beneath to continue my text so i do not reach the end of the page. from Tkinter import * root = Tk() w = Label(root, text=\n Hello, world! \n iv arrived) w.pack() root.mainloop() Thanks nige Try the Tkinter.Text widget. You can configure it to be read only, etc. so it behaves like a label. It will automatically wrap text for you and will put in line breaks (\n) where you tell it. See http://www.pythonware.com/library/tkinter/introduction/text.htm James -- James Stroud UCLA-DOE Institute for Genomics and Proteomics Box 951570 Los Angeles, CA 90095 http://www.jamesstroud.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: maximum() efficency
Actually, now that I think about it, the version using iter() has one advantage over your version: it will work correctly if passed either a list or an iterator. So, for versions of Python that have iterators, I'd use the iter() version, but for older versions of Python, I'd use your version. P.S. I benchmarked your version; it ran in 22.0 seconds, just a gnat's whisker faster than the iter() version. -- Steve R. HastingsVita est [EMAIL PROTECTED]http://www.blarg.net/~steveha -- http://mail.python.org/mailman/listinfo/python-list
Re: maximum() efficency
Steve R. Hastings [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On Sun, 26 Mar 2006 10:34:16 -0700, Steven Bethard wrote: What's the original? def minimum(cmp, lst): minimum(cmp, lst) Returns the minimal element in non-empty list LST with elements compared via CMP() which should return values with the same semantics as Python's cmp(). If there are several minimal elements, the last one is returned. if not lst: raise ValueError, 'empty list' minval = lst[0] for i in xrange(1, len(lst)): v = lst[i] if cmp(minval, v) 0: minval = v return minval This is from Google's goopy package. http://goog-goopy.sourceforge.net/ -- Steve R. HastingsVita est [EMAIL PROTECTED]http://www.blarg.net/~steveha The doc string is not correct. If there are several minimal elements, the *first* one is returned. See this example: import math class Vector(object): def __init__(self,*x): # x is list of n-dimensional coordinates self.x = x def magnitude(self): return math.sqrt(sum(x**2 for x in self.x)) def __cmp__(self,other): return cmp(self.magnitude(), other.magnitude()) def __str__(self): return Vector(%s) % ,.join(str(x) for x in self.x) a = Vector(0,1) b = Vector(0,0) c = Vector(1,0) # these print 1, -1, and 0 to show that cmp() and Vector are doing the right thing print cmp(a,b) print cmp(b,a) print cmp(a,c) print min(a,b) # gives Vector(0,0), or b print max(a,b,c) # gives Vector(0,1) or a print min(a,c)# gives Vector(0,1) or a print minimum(Vector.__cmp__, [a,b]) # gives Vector(0,0), or b print minimum(Vector.__cmp__, [a,c])# gives Vector(0,1) or a -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Python float representation error?
try running this in python: print [39.95] the output i get is: [39.953] what's up with that? That's perfectly normal - some numbers aren't exactly expressible as binary floating points, just like 1/3 isn't expressible as a decimal floating point number. Here's a good link on floating point arithmetic: http://docs.sun.com/source/806-3568/ncg_goldberg.html -- http://mail.python.org/mailman/listinfo/python-list
Re: New-style Python icons
[EMAIL PROTECTED] wrote: Personally, I *like* the new website look, and I'm glad to see Python having a proper logo at last! I've taken the opportunity to knock up some icons using it, finally banishing the poor old standard-VGA-palette snake from my desktop. If you like, you can grab them from: http://www.doxdesk.com/img/software/py/icons.zip I just wanted to say that I've been using these icons for almost a week now and I love them! I'd like to reiterate EuGeNe's request that these go into the Python 2.5 release if at all possible. STeVe -- http://mail.python.org/mailman/listinfo/python-list
determine file type
Is there an equivalent to the unix 'file' command? [mark tmp]$ file min.txt min.txt: ASCII text [mark tmp]$ file trunk trunk: directory [mark tmp]$ file compliance.tgz compliance.tgz: gzip compressed data, from Unix What I really want to do is determine if a file is 1) a directory, 2) a text file 3) a binary file. Is there a way to do this? Mark -- http://mail.python.org/mailman/listinfo/python-list
Re: PIL image size reduction script
Philippe Martin wrote: Hi, Thanks to the NG, I got the script hereunder working. 1) I am not certain that the call to convert does much (checking the doc) I think you only need it if your source image comes in a format that can't be stored into a jpeg file (e.g. 8-bit paletted). You'll need that if you're converting from GIF files, for example. It shouldn't hurt otherwise. 2) Can this be improved as far as the final image size in (X,Y) ? I'm not sure if I get you: You tell the image object it's new (X,Y)-size in the resize method, don't you? For instance, passing a large .jpg with a target byte size of 7000, I get final (X,Y) results around (213, 174) ... but might want to strech it a bit while keeping the byte size. If I got you right, you want to compress the image to a certain file size. Maybe you should try optimizing the additional save parameters for the jpeg encoder. (http://www.pythonware.com/library/pil/handbook/formats.htm). Try reducing the quality parameter. l_image.save(l_tmp_file_name, quality=25) Hope this helps. Niki -- http://mail.python.org/mailman/listinfo/python-list
