🌐 Mailman 3 October 2010 - Python-list - python.org

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by jf Nov. 9, 2010

Nov. 9, 2010

Hi, I've a project with tabs and spaces mixed (yes I know it's bad). I edit each file to remove tabs, but it's so easy to make a mistake. Do you know a tools to compare the initial file with the cleaned one to know if the algorithms are the same ? By comparing pyc files for example. Thanks.

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Re: functions, list, default parameters
by John Nagle Nov. 8, 2010

Nov. 8, 2010

On 10/21/2010 2:51 PM, Chris Rebert wrote: > On Thu, Oct 21, 2010 at 2:36 PM, Sean Choi<gnemnk(a)gmail.com> wrote: >> I found two similar questions in the mailing list, but I didn't understand >> the explanations. >> I ran this code on Ubuntu 10.04 with Python 2.6.5. >> Why do the functions g and gggg behave differently? If calls gggg(3) and >> g(3) both exit their functions in the same state, why do they not enter in >> the same state when I call gggg(4) and g(4)? >> >> # ---------------------------------------------------------------------- my >> code: >> def gggg(a, L=[]): > > This is a common newbie stumbling-block: Don't use lists (or anything > mutable) as default argument values That really should be an error. John Nagle

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how to handle network failures
by harryos Nov. 6, 2010

Nov. 6, 2010

hi I am trying to write a DataGrabber which reads some data from given url..I made DataGrabber as a Thread and want to wait for some interval of time in case there is a network failure that prevents read(). I am not very sure how to implement this class DataGrabber(threading.Thread): def __init__(self,url): threading.Thread.__init__(self) self.url=url def run(self): data=self.get_page_data() process_data(data) def get_page_data(): try: f=urllib.urlopen(self.url) data=f.read(1024) except IOError: #wait for some time and try again time.sleep(120) data=self.get_page_data() return data Is this the way to implement the part where the thread waits and reads the data again? Will this handle network failures?Can somebody please help? thanks harry

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Re: Why "flat is better than nested"?
by kj Nov. 6, 2010

Nov. 6, 2010

In <mailman.278.1288129342.2218.python-list(a)python.org> Steve Holden <steve(a)holdenweb.com> writes: >On 10/26/2010 2:44 PM, kj wrote: >> In <mailman.258.1288104186.2218.python-list(a)python.org> Steve Holden <steve(a)holdenweb.com> writes: >> >>> The answer is probably the same as you will see if you try >> >>> from __future__ import braces >> >>> That feature *is* available in Python 2.6 ;-) >> >> Now, that's hilarious. >> >See, there *is* a place for humor :) I have nothing against humor. The reason why I find "import braces" funny is that it is so obviously a joke. But I do find it mildly annoying (and just mildly) that a joke/hoax/farce like ZoP/this.py is built into the standard lib, because a lot of people (not just me) don't realize it's a joke. (In fact, the reason I learned about ZoP/this.py was that in a reply to some post of mine in some Python forum [maybe c.l.py], the responder simply told me to run "import this", with the implication that it would answer whatever it was that I was asking about. Either this person took ZoP seriously, or was just having fun at a noob's expense. Either way, I don't like it.) Learning a new programming language (which entails becoming familiar not only with some new syntax, but new libraries, new general ideas, new ways of doing stuff), is already disorienting enough as it is. I don't see the point of making the task any harder than it already is by injecting additional *gratuitous confusion* in the form pseudo-rogramming advice that apparently no experienced Python program really believes/takes seriously anyway. I just don't understand the need of having this.py in the std lib of all places. It's not like there's any risk of losing the ZoP if it were removed from it. Zillions of copies of it would be floating around in the web. But it would not be confused as something that is somehow endorsed by those who put together the distribution. I know. Not a chance. :) ~kj

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Re: Exception Handling in Python 3
by rantingrick Nov. 5, 2010

Nov. 5, 2010

On Oct 24, 7:36 am, Steve Holden <st...(a)holdenweb.com> wrote: > I don't want people to think this is a big deal, however. Nonsense, this IS a big deal. (and Steve grow a spine already!) I was not even aware of this issue until you brought it up -- although i will admit your choice of title is completely misleading! This new exception handling behavior is completely ridiculous and the only thing more atrocious than the new exception handling BUG you uncovered is the "hoop jumping" garbage people have come up with to make the "new" work as the tried and tested "old". I am the programmer, and when i say to my interpretor "show this exception instead of that exception" i expect my interpretor to do exactly as i say or risk total annihilation!! I don't want my interpreter "interpreting" my intentions and then doing what it "thinks" is best for me. I have a wife already, i don't need a virtual one! We are opening a Pandora's box of mediocrity and confusion when we start down such a slippery slope as this. Let me enlighten you fellows... If have i ever learned anything about programming, i can tell you one rule should always be counted on above all rules -- that the computer will do exactly what you tell it to do NOTHING more, and NOTHING less. End of story!

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newbie qns : how do i use xmldiff?
by sWrath swrath Nov. 5, 2010

Nov. 5, 2010

Hi , I am pretty new to python , and reading up on it. Basically I am trying to compare xml files . I know difflib have it but it does not work out as expected. I was looking at xmldiff , unfortunately I am not able to find documentation how to call it from python. Anyone knows a link or doc to it as I have been looking high and low for few days? lastly , is there a py (or algorithm) where it behaves exactly like diff ? Greatly appreciated. Thanks john

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Tools for turning Python code into XMI?
by Stefan Schwarzer Nov. 5, 2010

Nov. 5, 2010

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

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DateTime object
by jf Nov. 4, 2010

Nov. 4, 2010

Hi, I've a bug in my code and I'm trying de reproduce it. To trace the bug I print arguments, and it produces this: {'date': <DateTime '20091020T00:00:00' at 558d128>} My question is: what is: <DateTime '20091020T00:00:00' at 558d128>? I use mx.DateTime put if I print it I get: <mx.DateTime.DateTime object for '2010-10-29 13:13:25.55' at 7f0bb54e1298> So what kind of object <DateTime> is ? Thanks.

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str(int_var) formatted
by Tracubik Nov. 1, 2010

Nov. 1, 2010

Hi all, i've to convert integer x to string, but if x < 10, the string have to be '0x' instead of simple 'x' for example: x = 9 str(x) --> '09' x = 32 str(x) --> '32' x represent hour/minute/second. I can easily add '0' with a if then block, but is there a built-in way to add the '0' automatically? Thanks Nico

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import ImageGrab fails on Ubuntu 10.4
by News123 Nov. 1, 2010

Nov. 1, 2010

Hi, It's the first time I wanted to use ImageGrab. importing ImageGrab fails as seen below: $ python -c "import ImageGrab" Traceback (most recent call last): File "<string>", line 1, in <module> File "/usr/lib/python2.6/dist-packages/PIL/ImageGrab.py", line 34, in <module> import _grabscreen ImportError: No module named _grabscreen $ Is this an issue for all Ubuntu 10.4 releases or is this only failing on my host? Thanks in advance

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