Re: A Unique XML Parsing Problem
Devon, 24.10.2010 01:40: I must quickly and efficiently parse some data contained in multiple XML files in order to perform some learning algorithms on the data. I have thousands of files, each file corresponds to a single song. Each XML file contains information extracted from the song (called features). Examples include tempo, time signature, pitch classes, etc. > [...] I am a statistician and therefore used to data being stored in CSV- like files, with each row being a datapoint, and each column being a feature. I would like to parse the data out of these XML files and write them out into a CSV file. Any help would be greatly appreciated. Mostly I am looking for a point in the right direction. I have heard about Beautiful Soup but never used it. I am currently reading Dive Into Python's chapters on HTML and XML parsing. That chapter is mostly out of date, and BeautifulSoup is certainly not the right tool for dealing with XML, both for performance and compliance reasons. If you need performance, as you stated above, look at cElementTree in the stdlib. And I am also more concerned about how to use the tags in the XML files to build feature names so I do not have to hard code them. For example, the first feature given by the above code would be "track duration" with a value of 29.12331 If the rules are as simple as that (i.e. tag name + attribute name), it'll be easy going with ElementTree. Don't put too much effort into separating the data from the XML format, though. XML parsing is fast and has the clear advantage over CSV files that the data is safely stored in a well defined, expressive format, including character encoding and named data fields. Stefan -- http://mail.python.org/mailman/listinfo/python-list
Interface centering
sorry 4 the sillu question. I've designed a GUI. How can I center on the screen? (i.e. it's always launched in the center of the screen) cheers, Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: Interface centering
On Sun, Oct 24, 2010 at 12:21 AM, Jah_Alarm wrote: > sorry 4 the sillu question. > > I've designed a GUI. How can I center on the screen? (i.e. it's always > launched in the center of the screen) Which GUI toolkit did you use? Cheers, Chris -- http://mail.python.org/mailman/listinfo/python-list
newbie to python
I want to start python, I have just downloaded python compiler, Can somebody please tell me what python really is and explain its architecture, in what problems it is used and from where should I start? -- http://mail.python.org/mailman/listinfo/python-list
Re: Interface centering
hi, I'm using Tkinter cheers, Alex On 24 окт, 20:26, Chris Rebert wrote: > On Sun, Oct 24, 2010 at 12:21 AM, Jah_Alarm wrote: > > sorry 4 the sillu question. > > > I've designed a GUI. How can I center on the screen? (i.e. it's always > > launched in the center of the screen) > > Which GUI toolkit did you use? > > Cheers, > Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie to python
On Sun, Oct 24, 2010 at 12:29 AM, Hrishikesh wrote: > I want to start python, I have just downloaded python compiler, Most consider it an interpreter (though it does compile the source code into high-level bytecode). > Can > somebody please tell me what python really is A programming language. What's a question like that even mean? > and explain its > architecture, Define "architecture" in this context. > in what problems it is used Various and sundry; it's a general-purpose language. But see http://www.python.org/about/apps/ > and from where should I > start? The official tutorial of course. If you downloaded version 2.x: http://docs.python.org/tutorial/ If you downloaded version 3.x: http://docs.python.org/py3k/ Regards, Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie to python
Hrishikesh writes: > I want to start python, I have just downloaded python compiler, Can > somebody please tell me what python really is and explain its > architecture, in what problems it is used and from where should I > start? I would start by looking at http://www.python.org To learn Python, go through the tutorial: http://docs.python.org/tutorial/ -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie to python
On Oct 24, 12:48 am, Arnaud Delobelle wrote: > Hrishikesh writes: > > I want to start python, I have just downloaded python compiler, Can > > somebody please tell me what python really is and explain its > > architecture, in what problems it is used and from where should I > > start? > > I would start by looking at > > http://www.python.org > > To learn Python, go through the tutorial: > > http://docs.python.org/tutorial/ > > -- > Arnaud Thanks guys, I knew its an interpreter, mistakenly put compiler, I am reading the docs, any further programming issues I will post soon! -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie to python
Hrishikesh writes: > Thanks guys, > > I knew its an interpreter, mistakenly put compiler [...] Oops! You just started a flame war ;) -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception Handling in Python 3
Am 24.10.2010 07:01, schrieb Steve Holden: > I was somewhat surprised to discover that Python 3 no longer allows an > exception to be raised in an except clause (or rather that it reports it > as a separate exception that occurred during the handling of the first). I think you are misinterpreting what you are seeing. The exception being raised actually *is* an attribute error, and it actually is the attribute error that gets reported. It's only that reporting an exception that has a __context__ first reports the context, then reports the actual exception. You may now wonder whether it is possible to set __context__ to None somehow. See PEP 3134: Open Issue: Suppressing Context As written, this PEP makes it impossible to suppress '__context__', since setting exc.__context__ to None in an 'except' or 'finally' clause will only result in it being set again when exc is raised. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Interface centering
Jah_Alarm wrote:
> hi, I'm using Tkinter
>
> cheers,
>
> Alex
>
> On 24 окт, 20:26, Chris Rebert wrote:
>> On Sun, Oct 24, 2010 at 12:21 AM, Jah_Alarm wrote:
>> > sorry 4 the sillu question.
>>
>> > I've designed a GUI. How can I center on the screen? (i.e. it's always
>> > launched in the center of the screen)
>>
>> Which GUI toolkit did you use?
>>
>> Cheers,
>> Chris
First hit googling for 'tkinter center' is
http://www.daniweb.com/forums/thread66181.html
With minor stylistic changes this becomes:
from Tkinter import *
def center_window(w, h):
# get screen width and height
ws = root.winfo_screenwidth()
hs = root.winfo_screenheight()
# calculate position x, y
x = (ws//2) - (w//2)
y = (hs//2) - (h//2)
root.geometry('%dx%d+%d+%d' % (w, h, x, y))
root = Tk()
center_window(500, 300)
root.mainloop()
A good basic source for Tkinter programming is
http://infohost.nmt.edu/tcc/help/pubs/tkinter/
Geometry strings are explained here:
http://infohost.nmt.edu/tcc/help/pubs/tkinter/std-attrs.html#geometry
Peter
--
http://mail.python.org/mailman/listinfo/python-list
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Tools for turning Python code into XMI?
Hello, I'm looking for a tool which can read Python files and write a corresponding XMI file for import into UML tools. Ideally, the conversion tool should: - be open source or freeware - be available for Linux - be a command line tool - allow to specify exactly the Python files that should to be taken into account - include operations, together with their parameters - include attributes (in the UML sense) if possible (I know this isn't reliable) Here are some programs I found via PyPI or search engine and tried so far. All of them miss something I'd really like to have. - pyreverse (now included with Pylint): http://www.logilab.org/857 I think this has the most potential. You can specify the files to import on the command line. There are many output formats for the information from the Python code, but XMI doesn't seem to be included. There are a few formats that could be parsed and turned into XMI (plain, plain-ext). Unfortunately, pyreverse doesn't include the parameters of operations. - Umbrello: http://uml.sourceforge.net/ Umbrello is a graphical KDE tool. You can specify either single files or whole directories including subdirectories. In my case, one of the subdirectories is for unit tests, which clutters the UML model. Attributes (again, in the UML sense) are seemingly not considered but operations. The parameters and return values of the latter, however, are all output as of type "string". - Gaphor: http://gaphor.sourceforge.net/ Gaphor is a GUI tool allowing to specify the files one by one which might be ok for a few files but surely becomes tedious if there are some more. The generated diagram, which can be exported to XMI, lacks the parameters of the operations. Do you have any other suggestions for programs I should have a look at? Does someone even has written such a tool and has not published it yet? :) Stefan -- http://mail.python.org/mailman/listinfo/python-list
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Re: Exception Handling in Python 3
Steve Holden wrote: > On 10/24/2010 1:26 AM, Chris Rebert wrote: >>> I was somewhat surprised to discover that Python 3 no longer allows an >>> > exception to be raised in an except clause (or rather that it reports >>> > it as a separate exception that occurred during the handling of the >>> > first). >> > [snip] >>> > What >>> > is the correct paradigm for this situation? >> There doesn't seem to be one at the moment, although the issue isn't >> very serious. Your Traceback is merely being made slightly longer/more >> complicated than you'd prefer; however, conversely, what if a bug was >> to be introduced into your exception handler? Then you'd likely very >> much appreciate the "superfluous" Traceback info. >> >> Your quandary is due to the unresolved status of the "Open Issue: >> Suppressing Context" in PEP 3141 >> (http://www.python.org/dev/peps/pep-3134/ ). I guess you could start a >> discussion about closing that issue somehow. > > You're right about the issue not being serious, (and about the possible > solution, though I don't relish a lengthy discussion on python-dev) but > it does seem that there ought to be some way to suppress that > __context__. From the user's point of view the fact that I am raising > AttributeError because of some implementation detail of __getattr__() is > exposing *way* too much information. > > I even tried calling sys.exc_clear(), but alas that doesn't help :( You can install a custom excepthook: >>> import traceback, sys >>> from functools import partial >>> def f(): ... try: 1/0 ... except: raise AttributeError ... >>> f() Traceback (most recent call last): File "", line 2, in f ZeroDivisionError: int division or modulo by zero During handling of the above exception, another exception occurred: Traceback (most recent call last): File "", line 1, in File "", line 3, in f AttributeError >>> sys.excepthook = partial(traceback.print_exception, chain=False) >>> f() Traceback (most recent call last): File "", line 1, in File "", line 3, in f AttributeError Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Unix-head needs to Windows-ize his Python script (II)
On 2:59 PM, Lawrence D'Oliveiro wrote: In message , Dave Angel wrote: Presumably the original pythonw.exe was called that because it's marked as a windows-app. In win-speak, that means it has a gui. Applications that are not so-marked are console-apps, and get a console created if they weren't already started from one. That's where stdin/stdout/stderr get pointed. Which is completely backwards, isn’t it? No. GUI programs are marked as win-app, so w stands for "Windows". Non GUI programs run in the console. Non-gui programs came first, so that's the type that doesn't need any tags. No event loop, no window handlers. GUI programs are the exception. DaveA -- http://mail.python.org/mailman/listinfo/python-list
Interactive mode under DOS?
Hi, I'm trying to use the interactive mode under DOS for Python 2.7. As a newbie, I do NOT know what is the following problem: >>>world_is_flat=1 >>>if world_is_flat: . . . print "be carefule to be not fall out!" File "", line 2 print "be carefule to be not fall out!" ^ IndenatationError : expected an idented block >>> Enybody knows how to fix this simple issue? regards -- http://mail.python.org/mailman/listinfo/python-list
Re: Interactive mode under DOS?
On 10/24/10 21:37, huisky wrote: > Hi, > > I'm trying to use the interactive mode under DOS for Python 2.7. As a > newbie, I do NOT know what is the following problem: > world_is_flat=1 if world_is_flat: > .. . . print "be carefule to be not fall out!" > File "", line 2 > print "be carefule to be not fall out!" > ^ > IndenatationError : expected an idented block > > Enybody knows how to fix this simple issue? > Python is indentation-sensitive, you need to add some whitespace to the line after an if-statement: >>> world_is_flat=1 >>> if world_is_flat: ... print "be carefule to be not fall out!" ... be carefule to be not fall out! >>> -- http://mail.python.org/mailman/listinfo/python-list
Re: Interactive mode under DOS?
huisky wrote: > Hi, > > I'm trying to use the interactive mode under DOS for Python 2.7. As a > newbie, I do NOT know what is the following problem: > world_is_flat=1 if world_is_flat: > . . . print "be carefule to be not fall out!" > File "", line 2 > print "be carefule to be not fall out!" > ^ > IndenatationError : expected an idented block > > Enybody knows how to fix this simple issue? > > regards The lines that shall be executed when world_is_flat is True must be indented more than the if. If you don't follow this rule Python complains and raises an IndentationError. >>> if world_is_flat: ... print "be careful" File "", line 2 print "be careful" ^ IndentationError: expected an indented block The easiest way to indent in interactive mode is to hit TAB once: >>> if world_is_flat: ... print "be careful" ... be careful By the way, you should not retype your error messages because that is error prone. Instead cut and paste. I think there is an entry in the system menu of the dos window to help you do that. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception Handling in Python 3
On 10/24/2010 4:48 AM, Martin v. Loewis wrote: > Am 24.10.2010 07:01, schrieb Steve Holden: >> I was somewhat surprised to discover that Python 3 no longer allows an >> exception to be raised in an except clause (or rather that it reports it >> as a separate exception that occurred during the handling of the first). > > I think you are misinterpreting what you are seeing. The exception being > raised actually *is* an attribute error, and it actually is the > attribute error that gets reported. It's only that reporting an > exception that has a __context__ first reports the context, then reports > the actual exception. > I don't believe I *am* misinterpreting it. The fact of the matter is that the context is irrelevant to the user, and there should be some way to suppress it to avoid over-complicating the traceback. This behavior is quite reasonable during testing, but I would prefer to exclude an explicit raise directly in the except handler since that is hardly to be construed as accidental (whereas an exception in a function called in the handler perhaps *should* be reported). > You may now wonder whether it is possible to set __context__ to None > somehow. See PEP 3134: > > Open Issue: Suppressing Context > > As written, this PEP makes it impossible to suppress '__context__', > since setting exc.__context__ to None in an 'except' or 'finally' > clause will only result in it being set again when exc is raised. > I have already read that. Peter Otten has separately explained how to suppress the behavior using sys.excepthook, which appears to be a halfway satisfactory solution. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie to python
On 10/24/2010 3:29 AM, Hrishikesh wrote: > I want to start python, I have just downloaded python compiler, Can > somebody please tell me what python really is and explain its > architecture, in what problems it is used and from where should I > start? If you don't know the answers to *any* of those questions, one wonders why you "want to start Python". Perhaps you can explain, or is this simply trolling? regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception Handling in Python 3
On 10/24/2010 2:22 AM, Lawrence D'Oliveiro wrote: > In message , Steve > Holden wrote: > >> I was somewhat surprised to discover that Python 3 no longer allows an >> exception to be raised in an except clause (or rather that it reports it >> as a separate exception that occurred during the handling of the first). > > So what exactly is the problem? Exceptions are so easy to get wrong, it’s > just trying to report more info in a complicated situation to help you track > down the problem. Why is that bad? > >> In a class's __getattr__() method this means that instead of being able >> to say >> >> try: >> value = _attrs[name] >> except KeyError: >> raise AttributeError ... >> >> I am forced to write >> >> if name not in _attrs: >> raise AttributeError ... >> value = _attrs[name] > > I don’t see why. Presumably if you caught the exception in an outer try- > except clause, you would pick up your AttributeError, not the KeyError, > right? Which is what you want, right? Yes, *if the exception is caught* then it doesn't make any difference. If the exception creates a traceback, however, I maintain that the additional information is confusing to the consumer (while helpful to the debugger of the consumed code). I don't want people to think this is a big deal, however. It was just an "eh?" that I thought must mean I was missing some way of suppressing the additional traceback. Peter Otten has already provided a solution using sys.except_hook(). regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
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Re: A Unique XML Parsing Problem
Devon writes: > I must quickly and efficiently parse some data contained in multiple > XML files in order to perform some learning algorithms on the data. > Info: > > I have thousands of files, each file corresponds to a single song. > Each XML file contains information extracted from the song (called > features). Examples include tempo, time signature, pitch classes, etc. > An example from the beginning of one of these files looks like: > > > startOfFadeOut="29.12331" loudness="-12.097" tempo="71.031" > tempoConfidence="0.386" timeSignature="4" > timeSignatureConfidence="0.974" key="11" keyConfidence="1.000" > mode="0" modeConfidence="1.000"> > > > > > > > > > -60.000 > -59.897 > > > 0.589 > 0.446 > 0.518 > 1.000 > 0.850 > 0.414 > 0.326 > 0.304 > 0.415 > 0.566 > 0.353 > 0.350 > You could use XSLT to get the data. For example this xslt script extracts duration, tempo and time signature into a comma separated list. http://www.w3.org/2001/XMLSchema"; xmlns:xsl="http://www.w3.org/1999/XSL/Transform";> With xsltproc song.xsl song*.xml you would get your output. No python necessary. Or if you would like to use it inside a Python program, use lxml to call the xslt processor, or just XPath to extract the values and format them with Python. -- http://mail.python.org/mailman/listinfo/python-list
Re: A good decorator library
I thought about that. I won't use decorators for all the things. I will use it only to free the simulator users to set which methods they wanna log or save in a statistic, eq.: number of packets sent, received, lost... 2010/10/24, Tim Roberts : > Felipe Bastos Nunes wrote: >> >>Hi! I was looking for a good decorator library to study and make my >>own decorators. I've read the Bruce Eckel's blog at artima dot com. >>But I need some more examples. I'm building a WSN simulator like SHOX >>is in java, but programming it in python. I'd like to use decorators >>to set methods that would be logged as statistics and some more >>funcionalities like check a method to check the params' types. > > Be careful with this. Decorators have their uses, but it is very easy to > make a program completely unreadable through the unjudicious use of > decorators. > > It is not good programming to use a language freature just because it is > there. > -- > Tim Roberts, t...@probo.com > Providenza & Boekelheide, Inc. > -- > http://mail.python.org/mailman/listinfo/python-list > -- Felipe Bastos Nunes -- http://mail.python.org/mailman/listinfo/python-list
Re: Python3: API Documentation generator
On 27/09/2010 20:44, Ken Watford wrote:
On Mon, Sep 27, 2010 at 1:15 PM, Tim Diels wrote:
On 27/09/2010 09:02, Chris Rebert wrote:
On Sun, Sep 26, 2010 at 11:56 PM, Tim Dielswrote:
Hi all
I've just switched to python3 and it turns out my current API
documentation
generator (epydoc) no longer works. I am looking for a tool that reads
the
docstrings of all classes, ... in my project and turns it into HTML
documentation.
Sphinx (http://sphinx.pocoo.org/ ) is the new gold standard. You'll
want to enable the `autodoc` extension:
http://sphinx.pocoo.org/ext/autodoc.html
Cheers,
Chris
--
http://blog.rebertia.com
I tried, but it fails to run through python code that's not backwards
compatible with older python versions.
It fails with: ...autodoc can't import/find module 'pytilities', it reported
error: "invalid syntax (overload.py, line 55)"...
This is line 55 (runs in python3, not in python):
def process_args(self, *args, kwargs={})
As far as I'm aware, autodoc works by importing the modules and then
reading doctext straight from the __doc__ attributes.
So the module in question has to import correctly in whatever
interpreter Sphinx is using. You probably need to install Sphinx with
python3 to get it to use the right interpreter. If you're using
easy_install or pip, check if you have an easy_install-3.1 or pip-3.1
(or similar) script installed.
Sorry for the late reaction, but I still have trouble getting sphinx to
work with python3.
I downloaded the latest version at PyPI:
http://pypi.python.org/pypi/Sphinx/1.0.4
Ran:
python3 setup.py
And it failed with a syntax error at line 50 which happens to be an
old-styled print statement stating it requires at least py2.4.
I'd find it odd that the python3 documentation would refer to sphinx as
a good tool if the tool wouldn't support it, so am I downloading the
wrong package or ...?
Thanks in advance
Greetings
Tim
--
http://mail.python.org/mailman/listinfo/python-list
Re: Exception Handling in Python 3
On 10/24/10 16:01, Steve Holden wrote: > I was somewhat surprised to discover that Python 3 no longer allows an > exception to be raised in an except clause (or rather that it reports it > as a separate exception that occurred during the handling of the first). FYI, Java has a similar behavior. In Java, however, after a certain length, some of the older exceptions will be suppressed and will only print message informing that there are more exceptions above it. -- http://mail.python.org/mailman/listinfo/python-list
Re: Interactive mode under DOS?
On Oct 24, 1:15 pm, Peter Otten <__pete...@web.de> wrote: > huisky wrote: > > Hi, > > > I'm trying to use the interactive mode under DOS for Python 2.7. As a > > newbie, I do NOT know what is the following problem: > > world_is_flat=1 > if world_is_flat: > > . . . print "be carefule to be not fall out!" > > File "", line 2 > > print "be carefule to be not fall out!" > > ^ > > IndenatationError : expected an idented block > > > Enybody knows how to fix this simple issue? > > > regards > > The lines that shall be executed when world_is_flat is True must be indented > more than the if. If you don't follow this rule Python complains and raises > an IndentationError. > > >>> if world_is_flat: > > ... print "be careful" > File "", line 2 > print "be careful" > ^ > IndentationError: expected an indented block > > The easiest way to indent in interactive mode is to hit TAB once: > > >>> if world_is_flat: > > ... print "be careful" > ... > be careful > > By the way, you should not retype your error messages because that is error > prone. Instead cut and paste. I think there is an entry in the system menu > of the dos window to help you do that. > > Peter Excellent reply! thanks very much Peter. -- http://mail.python.org/mailman/listinfo/python-list
time difference interms of day
Hello I was wondering if there is an existing function that would let me determine the difference in time. To explain: Upon starting a program: startup = time.time() After some very long processing: now = time.time() On, doing now - startup I want the program to return in terms of days. How ? Thanks, Harsha. -- http://mail.python.org/mailman/listinfo/python-list
Re: time difference interms of day
On 10/24/2010 1:55 PM, mukkera harsha wrote: > Hello > I was wondering if there is an existing function that would let me > determine the difference in time. To explain: > > Upon starting a program: > > startup = time.time() > > After some very long processing: > now = time.time() > > > On, doing now - startup I want the program to return in terms of days. How ? > > > Thanks, > > Harsha. > You'd probably be better off using the datetime module. That way you can store datetime.datetime.now() at the start of your run and subtract datetime.datetime.now() at the end, giving you a datetime.delta object which contains days, seconds and microseconds: >>> import datetime >>> t1 = datetime.datetime.now() [waited a while] >>> t2 = datetime.datetime.now() >>> t2-t1 datetime.timedelta(0, 16, 509000) >>> regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: time difference interms of day
On 10/24/2010 07:55 PM, mukkera harsha wrote: On, doing now - startup I want the program to return in terms of days. How ? >>> import datetime >>> now = datetime.datetime.now() >>> after_few_seconds = datetime.datetime.now() >>> after_few_seconds - now datetime.timedelta(0, 14, 256614) >>> (after_few_seconds - now).seconds 14 Hope this helps :-) Jonas -- http://mail.python.org/mailman/listinfo/python-list
Re: yield all entries of an iterable
Hi Sebastian, On 2010-10-21 00:27, Sebastian wrote: > Is there a simpler way to yield all elements of a sequence than this? > for x in xs: > yield x Can you give an example where you would need this? Can't you just iterate over the sequence? If you really need an iterator, you can use `iter(sequence)`: >>> my_list = [1, 2, 3] >>> i = iter(my_list) >>> i.next() 1 >>> i.next() 2 >>> i.next() 3 >>> i.next() Traceback (most recent call last): File "", line 1, in StopIteration This works at least with Python's built-in sequences (and dictionaries and sets, but note that these don't have an obvious order). Stefan -- http://mail.python.org/mailman/listinfo/python-list
linking on OSX Snow Leopard
I'm not able to find the shared library version of Python3 on my Mac. There are libpython.dylib things for Python2. There is a Python3 libpython.a static lib. The docs on linking indicate a serious problem, there is mention of applications containing symbols needed by dynamically loaded extensions. Unfortunately this idea is seriously broken (on all platforms) and should not be used by quality products .. Python is quality product isn't it? The correct way to do this is for the extension to be explicitly linked against libpython so they find their symbols when loaded. The problem with linking against an application is that it may not be an application which is loading them .. it could be another shared library, and in my case it is. in any case I find this: ~/felix>ls -lasp /Library/Frameworks/Python.framework/Versions/3.1/bin/python3.1 64 -rwxrwxr-x 1 root admin 29560 2 Jun 2009 /Library/Frameworks/Python.framework/Versions/3.1/bin/python3.1 and clearly a 29K byte executable must be loading a shared library somehow, but only one is listed (the dynamic loader itself). Do I have to build Python myself to get around this deficiency? Does the build script handle this correctly? (The standard Python executable must be a thunk that doesn't nothing by run a function inside a shared library). Or has something changed in the build for Python 3, such as a collection of shared objects instead of a monolithic libpython? BTW: What I'm *actually* doing is: I have a compiler that generates shared libraries which are run by an fixed executable driver. I want to be able to run Python from inside my programs, but they're not "applications" they're shared libraries (.dylib on OSX). In addition, my compiler can produce Python extension modules, which I want to use from python scripts. Writing C extensions to Python is hard work for the average user. It should be much easier to use my language to define functions which can then be used in Python (but run millions of times faster). The most interesting option (for me, anyhow), is to do both at the same time: embed Python into my programs and use it to load the extension modules.. this allows Python to handle some of the dynamics. In particular my product's build script is entirely pure Python code (so everything builds on all platforms including Windows). We want to optionally replace some of the modules with compiled extensions, which I can produce, but I also want to USE some of the components from the build system inside my programs (which, recall, are shared libraries). -- john skaller skal...@users.sourceforge.net -- http://mail.python.org/mailman/listinfo/python-list
HTMLParser not parsing whole html file
Hello,
I wanted to use python to scrub an html file for score data, but I'm
having trouble.
I'm using HTMLParser, and the parsing seems to fizzle out around line
192 or so. None of the event functions are being called anymore
(handle_starttag, handle_endtag, etc.) and I don't understand why,
because it is a html page over 1000 lines.
Could someone tell me if this is a bug or simply a misunderstanding on
how HTMLParser works? I'd really appreciate some help in
understanding.
I am using Python 3.1.2 on Windows 7 (hopefully shouldn't matter).
I put the HTML file on pastebin, because I couldn't think of anywhere
better to put it:
http://pastebin.com/wu6Pky2W
The source code has been pared down to the simplest form to exhibit
the problem. It is displayed below, and is also on pastebin for
download (http://pastebin.com/HxwRTqrr):
import sys
import re
import os.path
import itertools as it
import urllib.request
from html.parser import HTMLParser
import operator as op
base_url = 'http://www.dci.org'
class TestParser(HTMLParser):
def handle_starttag(self, tag, attrs):
print('position {}, staring tag {} with attrs
{}'.format(self.getpos(), tag, attrs))
def handle_endtag(self, tag):
print('ending tag {}'.format(tag))
def do_parsing_from_file_stream(fname):
parser = TestParser()
with open(fname) as f:
for num, line in enumerate(f, start=1):
# print('Sending line {} through parser'.format(num))
parser.feed(line)
if __name__ == '__main__':
do_parsing_from_file_stream(sys.argv[1])
--
http://mail.python.org/mailman/listinfo/python-list
Re: HTMLParser not parsing whole html file
On Oct 24, 4:36 pm, josh logan wrote:
> Hello,
>
> I wanted to use python to scrub an html file for score data, but I'm
> having trouble.
> I'm using HTMLParser, and the parsing seems to fizzle out around line
> 192 or so. None of the event functions are being called anymore
> (handle_starttag, handle_endtag, etc.) and I don't understand why,
> because it is a html page over 1000 lines.
>
> Could someone tell me if this is a bug or simply a misunderstanding on
> how HTMLParser works? I'd really appreciate some help in
> understanding.
>
> I am using Python 3.1.2 on Windows 7 (hopefully shouldn't matter).
>
> I put the HTML file on pastebin, because I couldn't think of anywhere
> better to put it:http://pastebin.com/wu6Pky2W
>
> The source code has been pared down to the simplest form to exhibit
> the problem. It is displayed below, and is also on pastebin for
> download (http://pastebin.com/HxwRTqrr):
>
> import sys
> import re
> import os.path
> import itertools as it
> import urllib.request
> from html.parser import HTMLParser
> import operator as op
>
> base_url = 'http://www.dci.org'
>
> class TestParser(HTMLParser):
>
> def handle_starttag(self, tag, attrs):
> print('position {}, staring tag {} with attrs
> {}'.format(self.getpos(), tag, attrs))
>
> def handle_endtag(self, tag):
> print('ending tag {}'.format(tag))
>
> def do_parsing_from_file_stream(fname):
> parser = TestParser()
>
> with open(fname) as f:
> for num, line in enumerate(f, start=1):
> # print('Sending line {} through parser'.format(num))
> parser.feed(line)
>
> if __name__ == '__main__':
> do_parsing_from_file_stream(sys.argv[1])
Sorry, the group doesn't like how i surrounded the Python code's
pastebin URL with parentheses:
http://pastebin.com/HxwRTqrr
--
http://mail.python.org/mailman/listinfo/python-list
Re: Exception Handling in Python 3
On 10/23/2010 10:42 PM, Steve Holden wrote:
On 10/24/2010 1:26 AM, Chris Rebert wrote:
I was somewhat surprised to discover that Python 3 no longer
allows an
exception to be raised in an except clause (or rather that it
reports it as a separate exception that occurred during the
handling of the first).
[snip]
What is the correct paradigm for this situation?
There doesn't seem to be one at the moment, although the issue
isn't very serious. Your Traceback is merely being made slightly
longer/more complicated than you'd prefer; however, conversely,
what if a bug was to be introduced into your exception handler?
Then you'd likely very much appreciate the "superfluous" Traceback
info.
Your quandary is due to the unresolved status of the "Open Issue:
Suppressing Context" in PEP 3141
(http://www.python.org/dev/peps/pep-3134/ ). I guess you could
start a discussion about closing that issue somehow.
This is a traceback issue only, right? The semantics of
the code below shouldn't change in Py3.x, I hope:
try :
...
try :
x = 1/0 # in a real program, input data might cause a problem
except ZeroDivisionError as msg:
raise RuntimeError("Math error on problem: " + str(msg))
except RuntimeError as msg :
print("Trouble: " + str(msg))
I have code where I'm reading and parsing a web page,
a process which can produce a wide range of errors. A try-block
around the read and parse catches the various errors and creates a
single user-defined "bad web page" exception object, which is then
raised. That gets caught further out, and is used to record the
troubled web page, schedule it for a retest, and such. This is
normal program operation, indicative of external problems, not a
code error or cause for program termination with a traceback.
Are exception semantics changing in a way which would affect that?
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
Re: linking on OSX Snow Leopard
On Sun, Oct 24, 2010 at 4:15 PM, john skaller wrote: > I'm not able to find the shared library version of Python3 on my Mac. > There are libpython.dylib things for Python2. There is a Python3 > libpython.a static lib. > > > The docs on linking indicate a serious problem, there is mention > of applications containing symbols needed by dynamically loaded > extensions. > > Unfortunately this idea is seriously broken (on all platforms) and should > not be used by quality products .. Python is quality product isn't it? > > The correct way to do this is for the extension to be explicitly linked > against libpython so they find their symbols when loaded. > > The problem with linking against an application is that it may not > be an application which is loading them .. it could be another shared > library, and in my case it is. > > > in any case I find this: > > ~/felix>ls -lasp > /Library/Frameworks/Python.framework/Versions/3.1/bin/python3.1 > 64 -rwxrwxr-x 1 root admin 29560 2 Jun 2009 > /Library/Frameworks/Python.framework/Versions/3.1/bin/python3.1 > > and clearly a 29K byte executable must be loading a shared library somehow, > but only > one is listed (the dynamic loader itself). > > Do I have to build Python myself to get around this deficiency? > Does the build script handle this correctly? (The standard Python > executable must be a thunk that doesn't nothing by run > a function inside a shared library). Or has something changed > in the build for Python 3, such as a collection of shared objects > instead of a monolithic libpython? > > You're using a Mac OS X Framework. The structure of the frameworks is very specific. I believe that /Library/Frameworks/Python.framework/Versions/3.1/Python will be your shared library. If you want your program to behave appropriately on OS X, you may want to learn to use the Frameworks rather than just assuming you're on a standard Unix system. http://developer.apple.com/library/mac/#documentation/MacOSX/Conceptual/BPFrameworks/Frameworks.html > BTW: What I'm *actually* doing is: I have a compiler that generates shared > libraries which > are run by an fixed executable driver. I want to be able to run Python from > inside my programs, but they're not "applications" they're shared libraries > (.dylib on OSX). > > In addition, my compiler can produce Python extension modules, which I want to > use from python scripts. Writing C extensions to Python is hard work for the > average user. It should be much easier to use my language to define functions > which can then be used in Python (but run millions of times faster). > > The most interesting option (for me, anyhow), is to do both at the same > time: embed Python into my programs and use it to load the extension > modules.. this allows Python to handle some of the dynamics. > > In particular my product's build script is entirely pure Python code > (so everything builds on all platforms including Windows). > We want to optionally replace some of the modules with > compiled extensions, which I can produce, but I also > want to USE some of the components from the build > system inside my programs (which, recall, are shared > libraries). > > -- > john skaller > skal...@users.sourceforge.net > > > > > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie to python
On Oct 24, 7:31 am, Steve Holden wrote: > On 10/24/2010 3:29 AM, Hrishikesh wrote: > > > I want to start python, I have just downloaded python compiler, Can > > somebody please tell me what python really is and explain its > > architecture, in what problems it is used and from where should I > > start? > > If you don't know the answers to *any* of those questions, one wonders > why you "want to start Python". Perhaps you can explain, or is this > simply trolling? Steve, I highly doubt this is an example of trolling we have witnessed here. If it really *is* trolling then i would say the "alleged troller" should visit xah's site for a crash course in professional trolling ASAP because he's not very good at it -- i should know! However, i have a good sense that our new friend is just very inexperienced and looking for advice. He may have a very limited knowledge --or even no knowledge of computer programming-- so that would explain the "seemingly" nonsensicalness of his questions. But we must always remember that every one here (*ahem* and i mean everyone S- T-E-V-E-O!) had to start from the bottom and work his or her way up the ladder of knowledge. So next time please try to be a little less condescending. Thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception Handling in Python 3
On 10/24/2010 4:44 PM, John Nagle wrote: > Are exception semantics changing in a way which would affect that? No, I don't believe so. I simply felt that the traceback gives too much information in the case where an exception is specifically being raised to replace the one currently being handled. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie to python
On 10/24/2010 5:19 PM, rantingrick wrote: > On Oct 24, 7:31 am, Steve Holden wrote: >> On 10/24/2010 3:29 AM, Hrishikesh wrote: >> >>> I want to start python, I have just downloaded python compiler, Can >>> somebody please tell me what python really is and explain its >>> architecture, in what problems it is used and from where should I >>> start? >> >> If you don't know the answers to *any* of those questions, one wonders >> why you "want to start Python". Perhaps you can explain, or is this >> simply trolling? > > Steve, I highly doubt this is an example of trolling we have witnessed > here. If it really *is* trolling then i would say the "alleged > troller" should visit xah's site for a crash course in professional > trolling ASAP because he's not very good at it -- i should know! > > However, i have a good sense that our new friend is just very > inexperienced and looking for advice. He may have a very limited > knowledge --or even no knowledge of computer programming-- so that > would explain the "seemingly" nonsensicalness of his questions. But we > must always remember that every one here (*ahem* and i mean everyone S- > T-E-V-E-O!) had to start from the bottom and work his or her way up > the ladder of knowledge. So next time please try to be a little less > condescending. > Righty ho. regards s-t-e-v-e-o -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
How do I chain methods?
I tried the following... #!/usr/bin/python class foo: def first(self): print "Chad " def last(self): print "A " x = foo() y = x.first() y.last() But when I ran it, I got the following... [cdal...@localhost oakland]$ ./chain.py Chad Traceback (most recent call last): File "./chain.py", line 12, in ? y.last() AttributeError: 'NoneType' object has no attribute 'last' [cdal...@localhost oakland]$ -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On Sun, Oct 24, 2010 at 3:47 PM, chad wrote: > How do I chain methods? > I tried the following... > > #!/usr/bin/python > > class foo: > def first(self): > print "Chad " > > def last(self): > print "A " > > x = foo() > y = x.first() > y.last() > > But when I ran it, I got the following... > > [cdal...@localhost oakland]$ ./chain.py > Chad > Traceback (most recent call last): > File "./chain.py", line 12, in ? > y.last() > AttributeError: 'NoneType' object has no attribute 'last' > [cdal...@localhost oakland]$ Functions/methods without "return" statements, such as your last() and first(), implicitly return None, Python's equivalent of null. Python has no special support for method chaining; having your methods `return self` achieves the same effect however. Method chaining is usually* not idiomatic in Python. Most people would instead just write: x = foo() x.first() x.last() If you insist on method chaining, adding the aforementioned `return` statements would let you write: x = foo() x.first().last() Cheers, Chris -- *Notwithstanding magic SQL query builders and the like http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: yield all entries of an iterable
On 24Oct2010 20:58, Stefan Schwarzer wrote: | On 2010-10-21 00:27, Sebastian wrote: | > Is there a simpler way to yield all elements of a sequence than this? | > for x in xs: | > yield x | | Can you give an example where you would need this? Can't | you just iterate over the sequence? The usual example is when the sequence comes from inside. Example, closely resembling some code from on of my projects: def leaves(N): if N.isleaf: yield N for subN in N.subnodes: for leaf in leaves(subN): yield leaf which walks a tree structure returning leaf nodes. The point is that you're calling leaves() on the subnode and yiled them directly to the outside. The caller may not even know there are "subnodes". Cheers, -- Cameron Simpson DoD#743 http://www.cskk.ezoshosting.com/cs/ The Borg assimilated my race and all I got was this lousy tagline. - Cath Lawrence -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On Mon, Oct 25, 2010 at 8:47 AM, chad wrote: > I tried the following... > > > > #!/usr/bin/python > > class foo: > def first(self): > print "Chad " > > def last(self): > print "A " > > x = foo() > y = x.first() > y.last() > > But when I ran it, I got the following... > > [cdal...@localhost oakland]$ ./chain.py > Chad > Traceback (most recent call last): > File "./chain.py", line 12, in ? > y.last() > AttributeError: 'NoneType' object has no attribute 'last' > [cdal...@localhost oakland]$ What you want is this: >>> class Foo(object): ... def first(self): ... print "Chad " ... return self ... def last(self): ... print "A " ... return self ... >>> x = Foo() >>> y = x.first() Chad >>> y.last() A <__main__.Foo object at 0x1011d7ad0> >>> NB: You must return "self" in this case so you can do chained calls. cheers James -- -- James Mills -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On Mon, Oct 25, 2010 at 9:02 AM, Chris Rebert wrote: > Method chaining is usually* not idiomatic in Python. I don't agree but anyway... I've just not seen it commonly used amongst python programmers. cheers James -- -- James Mills -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On Oct 24, 4:11 pm, James Mills wrote: > On Mon, Oct 25, 2010 at 9:02 AM, Chris Rebert wrote: > > Method chaining is usually* not idiomatic in Python. > > I don't agree but anyway... I've just not seen it commonly used > amongst python programmers. > > cheers > James > I just saw this technique used in python script that was/is used to automatically log them in myspace.com. Hence the question. -- http://mail.python.org/mailman/listinfo/python-list
Re: yield all entries of an iterable
Hi Cameron, On 2010-10-25 01:08, Cameron Simpson wrote: > On 24Oct2010 20:58, Stefan Schwarzer wrote: > | On 2010-10-21 00:27, Sebastian wrote: > | > Is there a simpler way to yield all elements of a sequence than this? > | > for x in xs: > | > yield x > | > | Can you give an example where you would need this? Can't > | you just iterate over the sequence? > > The usual example is when the sequence comes from inside. > Example, closely resembling some code from on of my projects: > > def leaves(N): > if N.isleaf: > yield N > for subN in N.subnodes: > for leaf in leaves(subN): > yield leaf > > which walks a tree structure returning leaf nodes. > > The point is that you're calling leaves() on the subnode and yiled them > directly to the outside. The caller may not even know there are "subnodes". >From the question and the code snippet the OP gave I assumed he meant that there already was a sequence (i. e. linear structure) to begin with. By the way, I think a well-known example of what you describe is `os.walk`. Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On Mon, Oct 25, 2010 at 9:21 AM, chad wrote: > I just saw this technique used in python script that was/is used to > automatically log them in myspace.com. Hence the question. Function/Method Chaining is probably used a lot in Python itself: >>> x = 4 >>> x.__add__(1).__sub__(3) 2 The implementation of many common operators return self (the object you're working with). cheers James -- -- James Mills -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception Handling in Python 3
Steve Holden writes:
> I simply felt that the traceback gives too much information in the
> case where an exception is specifically being raised to replace the
> one currently being handled.
Ideally, that description of the problem would suggest the obvious
solution: replace the class of the exception and allow the object to
continue up the exception handler stack.
But that doesn't work either::
>>> d = {}
>>> try:
... val = d['nosuch']
... except KeyError as exc:
... exc.__class__ = AttributeError
... raise exc
...
Traceback (most recent call last):
File "", line 2, in
KeyError: 'nosuch'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "", line 4, in
TypeError: __class__ assignment: only for heap types
which means, AFAICT, that re-binding ‘__class__’ is only allowed for
objects of a type defined in the Python run-time heap, not those defined
in C code (like the built-in-exception types).
--
\ “I wish there was a knob on the TV to turn up the intelligence. |
`\ There's a knob called ‘brightness’ but it doesn't work.” |
_o__) —Eugene P. Gallagher |
Ben Finney
--
http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On 10/24/2010 7:39 PM, James Mills wrote: > On Mon, Oct 25, 2010 at 9:21 AM, chad wrote: >> I just saw this technique used in python script that was/is used to >> automatically log them in myspace.com. Hence the question. > > Function/Method Chaining is probably used a lot in Python itself: > x = 4 x.__add__(1).__sub__(3) > 2 > > The implementation of many common operators return self (the object > you're working with). > You surely aren't trying to suggest that (4).__add__(1) returns 4? regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: pythagorean triples exercise
"Tim Roberts" wrote in message news:5na7c6dlv0qii3pta58as50lmjcrrtk...@4ax.com... Baba wrote: a^a + b^b = c^c is the condition to satisfy No, it's not. It's a^2 + b^2 = c^2, where a, b, and c are integers. Perhaps you meant a*a + b*b = c*c. Or possibly a**2 + b**2 = c**2 and i need to use loops and "n" will be an upper limit of one (or more?) of the loops but i am a bit lost. Please help me get thinking about this right. The simplest (but not most efficient) method is brute force, using three loops, one each for a, b, and c. You can compute the largest "c" you will need by computing the square root of a*a+b*b. If square roots have to be used, you might as well use the two-loop algorithm, as you're nearly there. A simpler estimate for the largest c is just a+b, although it might involve a few extra iterations. -- Bartc -- http://mail.python.org/mailman/listinfo/python-list
Re: yield all entries of an iterable
On 25Oct2010 01:37, Stefan Schwarzer wrote: | From the question and the code snippet the OP gave I assumed | he meant that there already was a sequence (i. e. linear | structure) to begin with. I suspected that was your interpretation. | By the way, I think a well-known example of what you | describe is `os.walk`. Indeed. I'm surprised it didn't occur to me. Cheers, -- Cameron Simpson DoD#743 http://www.cskk.ezoshosting.com/cs/ The only thing necessary for the triumph of evil is for good men to do nothing. - Edmund Burke (1729-1797) -- http://mail.python.org/mailman/listinfo/python-list
How to optimize and monitor garbage collection?
I'm designing a system that will be very memory hungry unless it is "garbage-collected" very aggressively. In the past I have had disappointing results with the gc module: I noticed practically no difference in memory usage with and without it. It is possible, however, that I was not measuring memory consumption adequately. What's the most accurate way to monitor memory consumption in a Python program, and thereby ensure that gc is working properly? Also, are there programming techniques that will result in better garbage collection? For example, would it help to explicitly call del on objects that should be gc'd? TIA! ~kj -- http://mail.python.org/mailman/listinfo/python-list
Re: A Unique XML Parsing Problem
In message , Piet van Oostrum wrote: > With xsltproc song.xsl song*.xml you would get your output. > No python necessary. Is that supposed to be some kind of advantage? -- http://mail.python.org/mailman/listinfo/python-list
Re: Unix-head needs to Windows-ize his Python script (II)
In message , Dave Angel wrote: > On 2:59 PM, Lawrence D'Oliveiro wrote: >> >> In message >> , Dave Angel wrote: >> >>> Presumably the original pythonw.exe was called that because it's marked >>> as a windows-app. In win-speak, that means it has a gui. Applications >>> that are not so-marked are console-apps, and get a console created if >>> they weren't already started from one. That's where stdin/stdout/stderr >>> get pointed. >> >> Which is completely backwards, isn’t it? >> > No. GUI programs are marked as win-app, so w stands for "Windows". Non > GUI programs run in the console. You mean “GUI console”. So non-GUI apps get a GUI element whether they want it or not, while GUI ones don’t. That’s completely backwards. -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception Handling in Python 3
In message , Steve Holden wrote: > Yes, *if the exception is caught* then it doesn't make any difference. > If the exception creates a traceback, however, I maintain that the > additional information is confusing to the consumer (while helpful to > the debugger of the consumed code). Who needs the information more? -- http://mail.python.org/mailman/listinfo/python-list
Re: Unix-head needs to Windows-ize his Python script (II)
On 25/10/2010 02:19, Lawrence D'Oliveiro wrote: In message, Dave Angel wrote: On 2:59 PM, Lawrence D'Oliveiro wrote: In message , Dave Angel wrote: Presumably the original pythonw.exe was called that because it's marked as a windows-app. In win-speak, that means it has a gui. Applications that are not so-marked are console-apps, and get a console created if they weren't already started from one. That's where stdin/stdout/stderr get pointed. Which is completely backwards, isn’t it? No. GUI programs are marked as win-app, so w stands for "Windows". Non GUI programs run in the console. You mean “GUI console”. So non-GUI apps get a GUI element whether they want it or not, while GUI ones don’t. That’s completely backwards. No, it's not. The fact that the console is also a GUI window is an implementation detail: it happens to be displayed within a GUI environment. -- http://mail.python.org/mailman/listinfo/python-list
Re: HTMLParser not parsing whole html file
On Oct 24, 4:38 pm, josh logan wrote:
> On Oct 24, 4:36 pm, josh logan wrote:
>
>
>
>
>
> > Hello,
>
> > I wanted to use python to scrub an html file for score data, but I'm
> > having trouble.
> > I'm using HTMLParser, and the parsing seems to fizzle out around line
> > 192 or so. None of the event functions are being called anymore
> > (handle_starttag, handle_endtag, etc.) and I don't understand why,
> > because it is a html page over 1000 lines.
>
> > Could someone tell me if this is a bug or simply a misunderstanding on
> > how HTMLParser works? I'd really appreciate some help in
> > understanding.
>
> > I am using Python 3.1.2 on Windows 7 (hopefully shouldn't matter).
>
> > I put the HTML file on pastebin, because I couldn't think of anywhere
> > better to put it:http://pastebin.com/wu6Pky2W
>
> > The source code has been pared down to the simplest form to exhibit
> > the problem. It is displayed below, and is also on pastebin for
> > download (http://pastebin.com/HxwRTqrr):
>
> > import sys
> > import re
> > import os.path
> > import itertools as it
> > import urllib.request
> > from html.parser import HTMLParser
> > import operator as op
>
> > base_url = 'http://www.dci.org'
>
> > class TestParser(HTMLParser):
>
> > def handle_starttag(self, tag, attrs):
> > print('position {}, staring tag {} with attrs
> > {}'.format(self.getpos(), tag, attrs))
>
> > def handle_endtag(self, tag):
> > print('ending tag {}'.format(tag))
>
> > def do_parsing_from_file_stream(fname):
> > parser = TestParser()
>
> > with open(fname) as f:
> > for num, line in enumerate(f, start=1):
> > # print('Sending line {} through parser'.format(num))
> > parser.feed(line)
>
> > if __name__ == '__main__':
> > do_parsing_from_file_stream(sys.argv[1])
>
> Sorry, the group doesn't like how i surrounded the Python code's
> pastebin URL with parentheses:
>
> http://pastebin.com/HxwRTqrr
I found the error. The HTML file I'm parsing has invalid HTML at line
193.
It has something like:
Note there is no space between the closing quote for the "href" tag
and the class attribute. I guess I'll go through each file and correct
these issues as I parse them.
Thanks for reading, anyways.
--
http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On Mon, 25 Oct 2010 09:39:47 +1000, James Mills wrote: > On Mon, Oct 25, 2010 at 9:21 AM, chad wrote: >> I just saw this technique used in python script that was/is used to >> automatically log them in myspace.com. Hence the question. > > Function/Method Chaining is probably used a lot in Python itself: > x = 4 x.__add__(1).__sub__(3) > 2 > > The implementation of many common operators return self (the object > you're working with). I can't think of any operations on built-ins that return self, except in the special case of an identity operation. And even then, it's not common: >>> x = 2.5 >>> y = x.__add__(1) >>> y is x False >>> y = x.__add__(0) >>> y is x False Ah wait, no, I thought of one: __iadd__: >>> x = [2.5] >>> y = x.__iadd__([None]) >>> y is x True But: >>> x = 2.5 >>> y = x.__iadd__(1) Traceback (most recent call last): File "", line 1, in AttributeError: 'float' object has no attribute '__iadd__' By the way, in case any newbies out there are reading... ...if you're writing x.__add__(1).__sub__(3) instead of x + 1 - 3 then you're almost certainly doing it wrong. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On Mon, Oct 25, 2010 at 12:49 PM, Steven D'Aprano wrote: > ...if you're writing x.__add__(1).__sub__(3) instead of x + 1 - 3 then > you're almost certainly doing it wrong. It was just an example :) ... And this isn't python-tutor --James -- -- James Mills -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On Mon, Oct 25, 2010 at 9:39 AM, James Mills wrote: > Function/Method Chaining is probably used a lot in Python itself: > x = 4 x.__add__(1).__sub__(3) > 2 > > The implementation of many common operators return self (the object > you're working with). My apologies, this was a terribly example! int is immutable and __add__ nor __sub__ return self :) cheers James -- -- James Mills -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
[ANN]littletable 0.3 release
Announcing the 0.3 release of littletable (the module formerly known as dulce). The version includes (thanks to much help from Colin McPhail, thanks Colin!): - support for namedtuples as table objects - Python 3 compatibility - Table.pivot() to summarize record counts by 1 or 2 table attributes littletable (formerly dulce) is a simple ORM-like wrapper for managing collections of Python objects like relational tables. No schema definition is used; instead table columns are introspected from the attributes of objects inserted into the table, and inferred from index and query parameters. Tables can be: - indexed - queried - joined - pivoted - imported from/exported to .CSV files Also, every query or join returns a new full-fledged littletable Table - no distinction of Tables vs. DataSets vs. RecordSets vs. whatever. So it is easy to build up a complex database analysis from a succession of joins and queries. littletable is a simple environment for experimenting with tables, joins, and indexing, with a minimum of startup overhead. You can download littletable at http://sourceforge.net/projects/littletable/ - htmldocs can be viewed at http://packages.python.org/littletable/. -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On Sun, Oct 24, 2010 at 4:11 PM, James Mills wrote: > On Mon, Oct 25, 2010 at 9:02 AM, Chris Rebert wrote: >> Method chaining is usually* not idiomatic in Python. > > I don't agree but anyway... I've just not seen it commonly used > amongst python programmers. If Python wanted to encourage method-chaining-style, then list.sort(), list.reverse(), and several other built-in type methods would (ala Ruby) return self rather than None. Since they don't, and since "uncommon idiom" is a near-oxymoron, I think we can safely conclude that method chaining isn't idiomatic in Python. Not that it doesn't have specialized uses though (See asterisk note). Cheers, Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception Handling in Python 3
On 10/24/2010 7:51 PM, Ben Finney wrote: > which means, AFAICT, that re-binding ‘__class__’ is only allowed for > objects of a type defined in the Python run-time heap, not those defined > in C code (like the built-in-exception types). Yeah, that's a given. Ruby would probably let you do that, but Python insists that you don't dick around with the built-in types. And roghtly so, IMHO. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: How to optimize and monitor garbage collection?
On 10/24/2010 8:39 PM, kj wrote: > What's the most accurate way to monitor memory consumption in a > Python program, and thereby ensure that gc is working properly? Trust me, it is. But don't forget that CPython doesn't actually *use* the garbage collector until you start to create cyclic data structures. In their absence reference counting alone is sufficient to ensure that unused object memory is reclaimed. regards Steve [aside: in general, if you think your program is not working because of a bug in Python, look harder at your program]. -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I chain methods?
On 10/24/2010 11:42 PM, Chris Rebert wrote: > On Sun, Oct 24, 2010 at 4:11 PM, James Mills > wrote: >> On Mon, Oct 25, 2010 at 9:02 AM, Chris Rebert wrote: >>> Method chaining is usually* not idiomatic in Python. >> >> I don't agree but anyway... I've just not seen it commonly used >> amongst python programmers. > > If Python wanted to encourage method-chaining-style, then list.sort(), > list.reverse(), and several other built-in type methods would (ala > Ruby) return self rather than None. Since they don't, and since > "uncommon idiom" is a near-oxymoron, I think we can safely conclude > that method chaining isn't idiomatic in Python. Not that it doesn't > have specialized uses though (See asterisk note). > Yes, the Twisted guys use method chaining a lot - it's definitely idiomatic in that framework. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Unix-head needs to Windows-ize his Python script (II)
On 10/24/2010 9:40 PM, MRAB wrote: > On 25/10/2010 02:19, Lawrence D'Oliveiro wrote: >> In message, Dave >> Angel >> wrote: >> >>> On 2:59 PM, Lawrence D'Oliveiro wrote: In message , Dave Angel wrote: > Presumably the original pythonw.exe was called that because it's > marked > as a windows-app. In win-speak, that means it has a gui. Applications > that are not so-marked are console-apps, and get a console created if > they weren't already started from one. That's where > stdin/stdout/stderr > get pointed. Which is completely backwards, isn’t it? >>> No. GUI programs are marked as win-app, so w stands for "Windows". Non >>> GUI programs run in the console. >> >> You mean “GUI console”. So non-GUI apps get a GUI element whether they >> want >> it or not, while GUI ones don’t. That’s completely backwards. > > No, it's not. The fact that the console is also a GUI window is an > implementation detail: it happens to be displayed within a GUI > environment. and, in fact, the console is only a GUI window in a windowed system. It might be one of the console emulation windows that init starts under linux, or even a terminal connected to a computer by a serila line, for heavens sake. Let's not go overboard looking for things to disagree about ;-) regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Unicode questions
In message , Petite Abeille wrote: > Characters vs. Bytes And why do certain people insist on referring to bytes as “octets”? -- http://mail.python.org/mailman/listinfo/python-list
Re: Unicode questions
In message , Chris Rebert wrote: > There is no such thing as "plain Unicode representation". UCS-4 or UTF-16 probably come the closest. -- http://mail.python.org/mailman/listinfo/python-list
Re: Unicode questions
On Sun, Oct 24, 2010 at 10:43 PM, Lawrence D'Oliveiro wrote: > In message , Chris Rebert > wrote: > >> There is no such thing as "plain Unicode representation". > > UCS-4 or UTF-16 probably come the closest. How do you figure that? Cheers, Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: Want / Need Genuine Google Adsense Account for Rs.300/-
Google Adsense Account For Cheap rate : p.sathi...@gmail.com > On Wednesday, March 31, 2010 4:18 PM SWETHA wrote: > Genuine Google Adsense Account for Rs.300/- > > We will approve your google adsense approval. > > We will help you till you get the first adsense check. > > Please send your mobile number to pramesh0...@gmail.com , i will call > you with in 15 minutes and give you the google adsense account. > > High Price Reduction for multiple adsense accounts. > Submitted via EggHeadCafe - Software Developer Portal of Choice > ASP.NET 4.0 browser capabilities > http://www.eggheadcafe.com/tutorials/aspnet/668c15e2-9fe5-4a7a-94ac-001af0bf4d1b/aspnet-40-browser-capabilities.aspx -- http://mail.python.org/mailman/listinfo/python-list
Re: Unicode questions
On 10/25/2010 1:42 AM, Lawrence D'Oliveiro wrote: > In message , Petite > Abeille wrote: > >> Characters vs. Bytes > > And why do certain people insist on referring to bytes as “octets”? Because back in the old days bytes were of varying sizes on different architectures - indeed the DECSystem-10 and -20 had instructions that could be parameterized as to byte size. So octet was an unambiguous term for the (now standard) 8-bit byte. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: HTMLParser not parsing whole html file
josh logan, 25.10.2010 04:14: I found the error. The HTML file I'm parsing has invalid HTML at line 193. It has something like: Note there is no space between the closing quote for the "href" tag and the class attribute. I guess I'll go through each file and correct these issues as I parse them. HTMLparser is not made to deal with non-HTML input. You can take a look at lxml.html or BeautifulSoup (up to 3.0), which handle these problems a lot better. Stefan -- http://mail.python.org/mailman/listinfo/python-list
