Permit argparse global flags after subcommand
argparse, python
Solution
This is a perfect use case for `parents` argparse feature:
Sometimes, several parsers share a common set of arguments. Rather than repeating the definitions of these arguments, a single parser with all the shared arguments and passed to parents= argument to ArgumentParser can be used.
Define a base parent `ArgumentParser`, add arguments that will be shared across subparsers. Then, add subparsers and set your base parser as a parent by providing `parents` keyword argument:
parser = argparse.ArgumentParser()
subparsers = parser.add_subparsers(dest='subparser_name')
base_subparser = argparse.ArgumentParser(add_help=False)
# define common shared arguments
base_subparser.add_argument('--disable')
sp = subparsers.add_parser('compile', parents=[base_subparser])
# define custom arguments
sp = subparsers.add_parser('launch', parents=[base_subparser])
# define custom arguments
Note that `add_help=False` here helps to avoid problems with conflicting `help` argument.
Also see: Python argparse - Add argument to multiple subparsers.
Problem
I am using argparse to build a command with subcommands: mycommand [GLOBAL FLAGS] subcommand [FLAGS] I would like the global flags to work whether they are before or after the subcommand. Is there a clean way to do this that doesn't involve repeating code? For example: ``` parser = argparse.ArgumentParser() subparsers = parser.add_subparsers(dest='subparser_name') parser.add_argument('--disable') # This flag... sp = subparsers.add_parser('compile') sp.add_argument('zones', nargs='*') sp.add_argument('--disable') # Is repeated... sp = subparsers.add_parser('launch') sp.add_argument('zones', nargs='*') sp.add_argument('--disable') # over and over... ``` I want to do this for many flags, so repeating myself over and over seems... unpythonic.