import sys

if __name__ == '__main__':
    print(sum(map(float, sys.argv[1:])))

import sys

def add_all(nums):
    return sum(nums)

if __name__ == '__main__':
    command = sys.argv[1]
    nums = map(float, sys.argv[2:])
    if command == 'add':
        print(add_all(nums))

Add support for commands