Compiled main program

Gordon McMillan gmcm at hypernet.com
Wed Jun 16 18:25:57 CEST 1999


> [Clarence, posting a request for help managed to find the solution
> before committing himself -- but he's posting it anyway (with his
> solution) just to see what people think...]

Strangely enough,

>python test.pyc

seems to work!
 
> 
> One of the applications that I've written in Python (in fact, the
> first big one, a billing system for ISPs in operation for about two
> years now) consists of about 120 main programs, all running via CGI.
>  There is one that is particularly larger than the rest (the main
> program is about 900 lines; all the rest are less than 400) and,
> unlike the others, is used in a very 'interactive' way; that is,
> you'll have hundreds or maybe thousands of http transactions between
> your browser and it over the course of a half hour or an hour.  
> 
> Today I finally got around to something that's bugged me for a long
> time, namely, the fact that Python is compiling that program every
> one of those hundreds of times.  So I tried the obvious:
> 
> $ cat nph-pmtbatch
> #!/usr/local/bin/python
> import PmtBatchGuts
> $
> 
> This worked fine (and with a noticeable speed increase) until the
> execution path happened to intersect with one of various spots in my
> various modules that reference a name in __main__ (it's an object
> that gives access to the context of a login session).  Hoping
> against hope, I made sure nobody was looking and put this at the top
> of PmtBatchGuts.py:
> 
> # Because this is really a main, but pre-compiled, program
> __name__ = '__main__'
> 
> Didn't think it would work, and it didn't.  I figured that what I
> really wanted to do was mess with sys.modules somehow, but I don't
> know how to get a reference to the current module.  I assume that
>  sys.modules['__main__'] = <this module>
> would do it.  As distasteful as that is (do I hear retching in the
> back of the room?), I like it much more than changing
>  S = Session.Session()
> to
>  __main__.S = Session.Session()
> 
> 
> 
> Remembering that people have on occasion mentioned attributes that
> seem to be invisible unless you know they're there, I've just been
> trying random things and came up with this:
> 
> $ cat PmtBatchGuts.py
> import sys
> 
> class MakeMeMain:
>  def __init__(self):
>         sys.modules['__main__'] = sys.modules[self.__module__]
> x = MakeMeMain()
> del x
> 
> import Session
> S = Session.Session()
> ...
> 
> 
> This works, but I'm interested in the what the community thinks of
> it. TIA
> 
> -- 
> -=-=-=-=-=-=-=-=
> Clarence Gardner
> AvTel Communications
> Software Products and Services Division
> clarence at avtel.com
> 
> -- 
> http://www.python.org/mailman/listinfo/python-list

- Gordon




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