I have to write a command-line interface and I've seen I can use docopt and argparse.
I would like to know what are the main differences between the two so that I can make an enlightened choice.
Please stick to the facts. I don't want Wow. docopt. So beautiful. Very useful.
Docopt parses a doc string, whereas argparse constructs its parsing by creating an object instance and adding behaviour to it by function calls.
Example for argparse:
parser = argparse.ArgumentParser()
parser.add_argument("operation", help="mathematical operation that will be performed",
choices=['add', 'subtract', 'multiply', 'divide'])
parser.add_argument("num1", help="the first number", type=int)
parser.add_argument("num2", help="the second number", type=int)
args = parser.parse_args()
Example for docopt:
"""Calculator using docopt
Usage:
calc_docopt.py <operation> <num1> <num2>
calc_docopt.py (-h | --help)
Arguments:
<operation> Math Operation
<num1> First Number
<num2> Second Number
Options:
-h, --help Show this screen.
"""
from docopt import docopt
if __name__ == '__main__':
arguments = docopt(__doc__, version='Calculator with docopt')
print(arguments)
Note, that docopt uses Usage: and Options: sections for parsing. Here Arguments: is provided only for end-user convenience.