How to read/process command line arguments?

import sys

print("\n".join(sys.argv))

sys.argv is a list that contains all the arguments passed to the script on the command line. sys.argv[0] is the script name.

Basically,

import sys

print(sys.argv[1:])

The canonical solution in the standard library is argparse (docs):

Here is an example:

from argparse import ArgumentParser

parser = ArgumentParser()
parser.add_argument("-f", "--file", dest="filename",
                    help="write report to FILE", metavar="FILE")
parser.add_argument("-q", "--quiet",
                    action="store_false", dest="verbose", default=True,
                    help="don't print status messages to stdout")

args = parser.parse_args()

argparse supports (among other things):

• Multiple options in any order.
• Short and long options.
• Default values.
• Generation of a usage help message.

Just going around evangelizing for argparse which is better for these reasons.. essentially:

(copied from the link)

• argparse module can handle positional and optional arguments, while optparse can handle only optional arguments

• argparse isn’t dogmatic about what your command line interface should look like - options like -file or /file are supported, as are required options. Optparse refuses to support these features, preferring purity over practicality

• argparse produces more informative usage messages, including command-line usage determined from your arguments, and help messages for both positional and optional arguments. The optparse module requires you to write your own usage string, and has no way to display help for positional arguments.

• argparse supports action that consume a variable number of command-line args, while optparse requires that the exact number of arguments (e.g. 1, 2, or 3) be known in advance

• argparse supports parsers that dispatch to sub-commands, while optparse requires setting allow_interspersed_args and doing the parser dispatch manually

And my personal favorite:

• argparse allows the type and action parameters to add_argument() to be specified with simple callables, while optparse requires hacking class attributes like STORE_ACTIONS or CHECK_METHODS to get proper argument checking

There is also argparse stdlib module (an "impovement" on stdlib's optparse module). Example from the introduction to argparse:

# script.py
import argparse

if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'integers', metavar='int', type=int, choices=range(10),
         nargs='+', help='an integer in the range 0..9')
    parser.add_argument(
        '--sum', dest='accumulate', action='store_const', const=sum,
        default=max, help='sum the integers (default: find the max)')

    args = parser.parse_args()
    print(args.accumulate(args.integers))

Usage:

$ script.py 1 2 3 4
4

$ script.py --sum 1 2 3 4
10