[pypy-issue] [issue938] pypy 5 times smaller than cpython in smallish script

Alex Gaynor tracker at bugs.pypy.org
Thu Nov 24 17:56:54 CET 2011

Alex Gaynor <alex.gaynor at gmail.com> added the comment:

The problem is you are using += to concatinate strings in a loop.  CPython has 
obscure hacks to make this efficient, but on PyPy this has O(n**2) behavior.  
This patch http://paste.pocoo.org/show/512426/ significantly speeds it up for me 
(it's 5x faster than CPython on my machine).  I'm marking this as wontfix, as 
it's not strictly speaking a bug, however I'm thinking about ways we can 
automatically do this transformation.

nosy: +agaynor
status: unread -> wontfix

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