1# If the python interpreter is running that module (the source file)
2# as the main program, it sets the special __name__ variable to have
3# a value “__main__”. If this file is being imported from another
4# module, __name__ will be set to the module’s name.
5if __name__=='__main__':
6 # do something
1# Suppose this is foo.py.
2
3print("before import")
4import math
5
6print("before functionA")
7def functionA():
8 print("Function A")
9
10print("before functionB")
11def functionB():
12 print("Function B {}".format(math.sqrt(100)))
13
14print("before __name__ guard")
15if __name__ == '__main__':
16 functionA()
17 functionB()
18print("after __name__ guard")