Python flow of execution

Question

Can someone explain the flow of execution of a python program especially about the main function? It would be helpful if it is compared and contrasted with execution of C.

Answer 1

when you execute "python myprog.py" the python interpeter will start running the script line by line:

import os #import the os module
print "prints somthing"
def f(num): ... # define a function

a = 5 / 2.0 # calculating stuff stuff ... 
if __name__ == '__main__': #__name__ is '__main__' only if this was the file that was started by the interpeter
    f(a) #calling the function f...

In C there is special function "main" that will be executed at startup. this (as explained above is NOT true for python)