from sys import argv - what is the function of “script”

Question

I am reading \"Learn Python the Hard Way\" and was confused by the \"script\" part of the second line.

from sys import argv
script, filename = argv
         


        

Answer 1

argv is a list of the arguments to your program. Standard shell behavior includes the name of the program itself as the first argument in argv.

Python can assign multiple values at once if the number of variables on the left hand side equals the size of the list on the right hand side (it can also handle more cases, but that is the most basic). E.g.

script, filename = argv

is the same as

script = argv[0]
filename = argv[1]

Note also that that script will raise a ValueError if argv does not have exactly two elements.