I'm a newbie to web technology, and still on a learning curve.
Heard that, fastcgi would keep the compiled(interpreted) php code in memory, so why would one has to use op-code caching (apc or eaccelerators) for PHP? 
But I never heard of any such accelerators for Python. I'd expect as python and php are both interpreted language, it makes me think that, there has to be a room for python accelerators ? pls correct me if I'm wrong. 
Many thanks
Python is compiled to bytecode when executed (the .pyc files), and the bytecode is kept around, not discarded. The compiled python is used instead of the source if it is present. Therefore, there is no need for additional opcode caching in python as it is already built in.
Why would one use accelerators with fastcgi for PHP?