if you run in the same file there is no difference. Block under "__main__" will be executed if you run that file only but if you import that file from another file, then if you don't put your code inside "__main__" your code it will be executed (this is not what you want).
Example: You have 1 file called mydll.py inside mydll you have : def func1(): print 'Helo world' # you want to test your func1() func1() # when you run you get 'Helo world' then you have another file called MyCode.py which you like to call func1(), inside this file you have this code: import mydll mydll.func1() # you hope you get 'Helo World' # In fact you get : # 'Helo World' # 'Helo World' -------------- This happened because when you import mydll python will execute all code in mydll including the one you put it for test. So to overcome this problem if you want to test your code put inside block __main__, next time you import your mydll it won't execute any codes inside __main__ Hope this help. Pujo -- http://mail.python.org/mailman/listinfo/python-list
