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.
This is a much more difficult question to answer than people are willing to admit.  
For example, it may be that I am able to write a program that performs better in Python than it does in C.  The fallacious conclusion from that statement is "Python is therefore faster than C".  In reality, it may be because I have much more recent experience in Python and its best practices and standard libraries.  
In fact no one can really answer your question unless they are certain that they can create an optimal solution in both languages, which is unlikely.  In other words "My C solution was faster than my Python solution" is not the same as "C is faster than Python"
I'm willing to bet that Guido Van Rossum could have written Python solutions for adam and Dustin's problems that performed quite well.
My rule of thumb is that unless you are writing the sort of application that requires you to count clock cycles, you can probably achieve acceptable performance in Python.
Python Performance - have you ever had to rewrite in something else?