[Tutor] PyDoc problem
kent37 at tds.net
Fri Sep 23 13:53:14 CEST 2005
Christian Meesters wrote:
> PyDoc is working well, if invoked without flags on the modul in
> question. But when I use it with '-w' to produce html-output, I get an
> extremely long Traceback after a runtime of an hour or two. Here is a
> short part from it:
> python2.3/sre.py", line 137, in search
> return _compile(pattern, flags).search(string)
> RuntimeError: maximum recursion depth exceeded
> What's going wrong? When I ask Pydoc to write html documentation for
> other modules there is no problem at all. It just works fine. And this
> traceback tell me nothing about my module, only about PyDoc. For it
> matters: I'm stuck with Python2.3 for compatibility reasons in this
> project and the module I'd like to see documented uses scipy and it is
> not really a small module anymore (about 1000 lines, including
> docstrings and comments).
Some re searches in Python 2.3 can cause stack overflow. It looks like you may be running in to that problem. It is fixed in Python 2.4; could you use 2.4 to run pydoc?
Here is the relevant section of the Python 2.4 release notes:
The re module is also no longer recursive, thanks to a massive amount of work by Gustavo Niemeyer. In a recursive regular expression engine, certain patterns result in a large amount of C stack space being consumed, and it was possible to overflow the stack. For example, if you matched a 30000-byte string of "a" characters against the expression (a|b)+, one stack frame was consumed per character. Python 2.3 tried to check for stack overflow and raise a RuntimeError exception, but certain patterns could sidestep the checking and if you were unlucky Python could segfault. Python 2.4's regular expression engine can match this pattern without problems.
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