What does if __name__ == "__main__": do?

The special __name__ variable in Python is a string that contains the name of the current module. If the module is the main program, __name__ will be set to the string "__main__".

The if __name__ == "__main__": idiom is used to execute some code only if the file containing it is being run as the main program. This is useful for breaking up a program into multiple files, or for running code that should only be run when the module is being run as a program, rather than being imported as a module.

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Here is an example of how if __name__ == "__main__": is used:

def main():
    # code to be executed

if __name__ == "__main__":
    main()

In this example, the main() function will be executed only if the file containing it is being run as the main program. If the file is being imported as a module into another program, the main() function will not be run.