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  • Python, import, module

    When the interpreter reads a python script file, it does two things:

    (1) set some special variable.

    (2) it executes all the code from 1st line of that script file.

      __name__ (2 underscores before and after) is a special python variable.

    we can import this script as a module.

    and also execute this script directly that the interpreter will assign the hard-coded string "__main__" to the __name__ variable

    # foo.py
    # I am using python 3.4
    print ("Befor foo function.") def foo(): print ("foo function.") print ("After foo function.")
    if __name__ == "__main__": foo()

    if we run it with

    $ python foo.py

    then the result is :

    Befor foo function.
    After foo function.
    foo function.

    and if we import it, then run $ python hello.py

    # hello.py
    import foo

     the running result is:

    Befor foo function.
    After foo function.
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  • 原文地址:https://www.cnblogs.com/sarah-zhang/p/12057869.html
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