test.py

import sys

def foo(n):
    n = int(n)
    for i in range(n):
        print(i + 1)

if len(sys.argv) > 1:
    foo(sys.argv[1])
else:
  print("Usage: python3 test.py <n>")

test2.py

import sys

if len(sys.argv) > 1:
    if sys.argv[1] == 'color' and sys.argv[2]:
        color = sys.argv[2]
    elif sys.argv[1] == 'nocolor':
        color = 'white'

else:
    print("Usage:")
    print("python3 test2.py color red")
    print("python3 test2.py nocolor")

test3.py

import sys

if len(sys.argv) > 1:
    if 'aus' in sys.argv:
        greeting = "G'day mate!"
    elif 'usa' in sys.argv:
        greeting = 'Howdy!'
    else:
        greeting = 'Hello.'

    if 'polite' in sys.argv:
        seat = 'Please take a seat.'
    else:
        seat = 'Take a seat.'

    print(f"{greeting} {seat}")

else:
    print("Usage:")
    print("python3 test2.py polite")
    print("python3 test2.py aus")
    print("python3 test2.py aus polite")
    print("python3 test2.py polite usa")