Has anyone ever had code in Python, that turned out not to perform fast enough?
I mean, you were forced to choose another language because of it?
We are investigating using Python for a couple of larger projects, and my feeling is that in most cases, Python is plenty fast enough for most scenarios (compared to say, Java) because it relies on optimized C routines.
I wanted to see if people had instances where they started out in Python, but ended up having to go with something else because of performance.
Thanks.
I generally don't rewrite to C  before I :

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rewrite with bette algorithms (generally this is enough)
rewrite python code with low level performance in mind (but never to the point of having non pythonic / non readable code)
spend some time rechecking a library cannot do this (first in stdlib, or an external lib)
tried psyco / other implementations (rarely achieves to get a REAL speed boost in my case)

Then sometimes I created a shared library to do heavy matrix computation code (which couldn't be done with numarray) and called it with ctypes : 

simple to write/build/test a .so / dll in pure C, 
simple to encapsulate the C to python function (ie. you don't if you use basic datatypes since ctypes does all the work of calling the right arguments for you) and certainly fast enough then .
Python Performance - have you ever had to rewrite in something else?