Permit argparse global flags after subcommand

Question

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 befor

Answer 1

You are asking for argparse solution, but as you also call for a Pythonic solution, I will deliberately propose an alternative using package docopt:

get it:

$ pip install docopt

Write your code into mycommand file:

"""
Usage:
    mycommand compile [--disable] ...
    mycommand launch  [--disable] ...

Arguments:
      zone name

Options:
  -h --help
  --disable  disable

"""
from docopt import docopt

if __name__ == "__main__":
    args = docopt(__doc__)
    print args

Then call it from command line:

basic help (no arguments):

$ python mycommand
Usage:
    mycommand compile [--disable] ...
    mycommand launch  [--disable] ...

Asking for a help:

$ python mycommand -h
Usage:
    mycommand compile [--disable] ...
    mycommand launch  [--disable] ...

Arguments:
      zone name

Options:
  -h --help
  --disable  disable

Using compile subcommand:

$ python mycommand compile zoneAlfa zoneBeta
{'--disable': False,
 '': ['zoneAlfa', 'zoneBeta'],
 'compile': True,
 'launch': False}

add flag --disable:

$ python mycommand compile --disable zoneAlfa zoneBeta
{'--disable': True,
 '': ['zoneAlfa', 'zoneBeta'],
 'compile': True,
 'launch': False}

launch subcommand works too:

$ python mycommand launch --disable zoneAlfa zoneBeta
{'--disable': True,
 '': ['zoneAlfa', 'zoneBeta'],
 'compile': False,
 'launch': True}

My usage of argument parsers started with argparse too, and I hated the complexity of code, which was needed for doing something.

Later I turned into plac, which is very efficient way for turning a python function into very usable command for console.

Still, I was limited by set of rules to follow and understand, which were not very clear to me in many cases. With docopt I appreciate, that I can write the docstring first, following standard rules of POSIX, and then use it in my code. If you would care about validation of arguments, I will direct you to samples of this great package.