[Python-Dev] maximum recursion depth exceeded in lib\pstats.py (original) (raw)

Adam Bielański ab at rdprojekt.pl
Thu Oct 21 13:20:12 CEST 2010

Hi all,

There's a bug in Python 2.6, module lib\pstats.py, line 150. I'm pretty sure, however that it also exists in other versions, as I don't think that profiler differs very much between them.

Let me paste a little piece of surrounding code:

 class Stats:
   (....)
     def add(self, *arg_list):
         if not arg_list: return self
         if len(arg_list) > 1: self.add(*arg_list[1:])  #Line 150, the

problem is right here! other = arg_list[0] (... do some processing with first item from arg_list ...)

This is the code for adding profiling stats from multiple files (names are on arg_list) so that they can be displayed in cumulated and readable form.

As you can see it chops off the first item from the list and then uses recursion to process the rest of it. It's no wonder then that when you profiled a little too many function calls, you're bound to see RuntimeError with 'maximum recursion depth exceeded' message when you try using this. IMO this should be done with iteration instead, like:

     def add(self, *arg_list):
         if not arg_list: return self
         for other in arg_list: #Preserved variable name only for sake of

comparison with previous snippet (... do some processing with each item from arg_list, merging results in some rightful manner ...)

Kind regards, Adam Bielanski.

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