Python Tutorial: argparse advanced-help with additional options

thing.py

#!/usr/bin/env python3

import sys
import argparse

long_help = False
for arg in sys.argv:
    if arg == "--":
        break
    if arg == "--long-help":
        long_help = True

parser = argparse.ArgumentParser()

parser.add_argument(
    "-f",
    "--with-filename",
    action="store_true",
    default=False,
    help="print for each playlist file the path to stderr",
)

parser.add_argument(
    "-s",
    "--sort",
    action="append",
    help="sort all game items by value of chosen key, before filter, *multi"
    if long_help
    else "sort all items",
)

parser.add_argument(
    "-c",
    "--count",
    action="store_true",
    default=False,
    help="print only a count of matching items per list, output file unaffected"
    if long_help
    else argparse.SUPPRESS,
)

if long_help:
    args = parser.parse_args(sys.argv[0:0] + ["--help"] + sys.argv[1:])
else:
    args = parser.parse_args()

What is this?

A way to handle a so called advanced help menu, where additional options are listed that are otherwise hidden with regular help. Hidden options should still function. This is just to have less clutter in normal view.

I've researched the web to see how people does it, and this is the way I like most so far. If you think this is problematic, please share your thoughts. This is for a commandline terminal application, that could also be automated through a script.

Before the ArgumentParser() is called, we check the sys.argv for the trigger option --advanced-help. Depending on this we set a variable to true or false. Then with the setup of the parser after the ArgumenParser() call, we add the --advanced-help option to the list of regular help.

advanced_help = False
for arg in sys.argv:
    if arg == "--":
        break
    if arg == "--advanced-help":
        advanced_help = True

parser = argparse.ArgumentParser()

Continue setting up your options as usual. But for the help description of those you want to exclude when using just regular -h, add an inline if else statement (ternary statement). This statement will put the help description only if advanced_help variable is true, otherwise it puts argparse.SUPPRESS to hide the option. Do this with all the options you want to hide.

parser.add_argument(
    "-c",
    "--count",
    action="store_true",
    default=False,
    help="print only a count of matching items per list, output file unaffected"
    if advanced_help
    else argparse.SUPPRESS,
)

Or instead hiding the option with argparse.SUPPRESS, one could also just display a short option description instead. This way those displayed with -h would have short explanation and when using the advanced help, it would display the long description.

parser.add_argument(
    "-s",
    "--sort",
    action="append",
    help="sort all game items by value of chosen key, before filter, *multi"
    if advanced_help
    else "sort all items",
)

At last we need to actually parse what you just setup. For this we need to assign our custom list, that is based on the sys.argv, plus the regular --help option. This way we can use --advanced-help without the need for -h or --help in addition to show any help message.

if advanced_help:
    args = parser.parse_args(sys.argv[0:0] + ["--help"] + sys.argv[1:])
else:
    args = parser.parse_args()

Run following program once with ./thing.py -h and ./thing.py --advanced-help.