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Python

Posted by Devin Hight
Devin Hight
3,141 Points

Why do we need sys.argv[1] exactly?

I'm still unsure about the functionality/necessity of this whole area under the
name == 'main': function. Is it just a way to index the contents of the file?

Jassim Alhatem
Jassim Alhatem
20,883 Points

Hey mate, can you add in the code please?

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,454 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points

I would need to see the referenced code to understand how says.argv[1] is being used. In regular use, sys.argv[1] refers to the second word on the command line. argv[0] usually refers to the program name “python”.

Regarding the use of __name__:

Keep in mind that any python file may be imported to any other file. The “if __name__ == "__main__"” idiom is used to tell whether the current file is being executed as the top level module or if has been imported into another Python file.

Each python file has its own namespace to hold variables. The name of the current file is held in this namespace as the variable __name__. However, if the file was invoked using python filename.py then, instead of the filename, the string “__main__” is assigned. So, by using this idiom, the code under this if statement can be restricted to run if and only if the current file was called directly by the python interpreter as the top module.

Post back if you need more help. Good luck!!!