jkawamoto/dsargparse

Simple Example
===============

Suppose to make a following trivial greeting command consists of two subcommands
supplied as functions shown below.

.. code-block:: python

    """Sample command of dsargparse package.

    This text will be used as description of this command.
    """
    def greeting(title, name): # pylint: disable=unused-argument
        """Print a greeting message.

        This command print "Good morning, <title> <name>.".

        Args:
          title: title of the person.
          name: name of the person.
        """
        print("Good morning, {title} {name}.".format(**locals()))
        return 0


    def goodbye(name): # pylint: disable=unused-argument
        """Print a goodbye message.

        This command print "Goodbye, <name>.".

        Args:
          name: name of the person say goodbye to.
        """
        print("Goodbye, {name}".format(**locals()))
        return 0


The `dsargparse` reduces codes you need from the **before**

.. code-block:: python

    # Before dsargparse
    import sys
    import textwrap

    import argparse

    def main():
        """ The main function.
        """
        parser = argparse.ArgumentParser(
          description=textwrap.dedent("""\
            Sample command of argparse package.

            This text will be used as description of this command.
            """))
        subparsers = parser.add_subparsers()

        greeting_cmd = subparsers.add_parser(
            "greeting",
            help="Print a greeting message.",
            description=textwrap.dedent("""\
                Print a greeting message.

                This command print "Good morning, <title> <name>".
                """))
        greeting_cmd.add_argument(
            "title", help="title of the person say greetings to")
        greeting_cmd.add_argument(
            "name", help="name of the person say greetings to.")
        greeting_cmd.set_defaults(cmd=greeting)

        goodbye_cmd = subparsers.add_parser(
            "goodbye",
            help="Print a goodbye message.",
            description=textwrap.dedent("""\
                Print a goodbye message.

                This command print "Goodbye, <name>".
                """))
        goodbye_cmd.add_argument(
            "name", help="name of the person say goodbye to.")
        goodbye_cmd.set_defaults(cmd=goodbye)

        args = parser.parse_args()
        return args.cmd(**args)


    if __name__ == "__main__":
        sys.exit(main())

to the **after**

.. code-block:: python

    # After dsargparse
    import sys

    import dsargparse

    def main():
        """ The main function.
        """
        parser = dsargparse.ArgumentParser(main=main)
        subparsers = parser.add_subparsers()

        greeting_cmd = subparsers.add_parser(greeting)
        greeting_cmd.add_argument("title")
        greeting_cmd.add_argument("name")

        goodbye_cmd = subparsers.add_parser(goodbye)
        goodbye_cmd.add_argument("name")

        return parser.parse_and_run()


    if __name__ == "__main__":
        sys.exit(main())