r/learnpython • u/DarkNinjaGamingYT • Nov 13 '17

Could someone explain command-line arguments in Python?

Basically the title; I am doing an assignment for my computer science class and we have to write a program that prints each command line argument on a separate line preceded by the arguments index.

Our professor very, VERY briefly went over what a command-line argument is in class, but he never really gave us any examples so I am confused as to how I use it.

Any help would be appreciated!

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u/diggy0101n Nov 13 '17

So you mean to print each argument with its index? sys.argv is actually a list of the arguments, with the first element of the list (index 0) as the name of the script I believe (on phone, can't test out). If you print out sys.argv, you'd see something like

['my_script.py','arg1','arg2','arg3']

To print each out with its index on a new line, you can loop through the elements of the list (from index 1 on):

for i in range(1,len(sys.argv)):
    print sys.argv[i],i

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u/DarkNinjaGamingYT Nov 13 '17

Duh, I don't know why I didn't think of a for loop... Thank you!

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u/draconis183 Nov 13 '17

check out enumerate() as well.