Python is (usually) an interpreted language, meaning that the script has to be read line-by-line at runtime and its instructions compiled into usable bytecode at that point.
C is (usually) a compiled language, so by the time you're running it you're working with pure machine code.
Python will never be as fast as C, for that reason.
Edit: In fact, python compiles INTO C code at run time, that's why you get those .pyc files.
