Pass key/value pairs to a python script using CLI arguments using Argparse

testing_args.py

"""
Sample script to parse arguments in the form of foo=bar and return a dict value
"""
import argparse


class ParseTags(argparse.Action):
    """
    This class overrides the argparse.Action __call__ method to evaluate
    the arguments, create a dict, and then return that dict as the argument's
    value.
    """

    def __call__(self, parser, namespace, values, option_string=None):
        setattr(namespace, self.dest, {})
        tags = []  # Temporary working variable
        for value in values:
            # The whole point of this loop is to split out multiple
            # key/value pairs into their own list elements
            # Example ['foo=bar', 'up=down']
            if "," in value:
                if value.strip() == ",":
                    # This covers the `foo=bar , sun=moon` situation
                    # because the ',' will be its own argument and cause
                    # a crash.
                    continue
                if value.strip().endswith(","):
                    # This covers the ending of the argument being a ','
                    # such as `foo=bar,up=down,`
                    # by eliminating the ending ','
                    value = value.strip()[:-1]
                if value.strip().startswith(","):
                    # This covers the scenario where the ',' is at the
                    # beginning of the paramenters, such as
                    # `,foo=bar,up=down`
                    value = value.strip()[1:]
                # This needs to be a += to properly add to the tags list
                # In `foo=bar,up=down`, using .append() here results in
                # ['foo=bar','u','p','=','d','o','w','n']
                tags += value.split(",")
            else:
                # The .append() works here because only 1 element is being added
                tags.append(value)
        for tag in tags:
            # This loop is where we split the tags list and then "reassemble"
            # the pieces into a dictionary.
            key, value = tag.split("=")
            getattr(namespace, self.dest)[key] = value


myparser = argparse.ArgumentParser(
    description="Testing script for argument parsing of keys and values"
)
myparser.add_argument("--opt1", nargs="?", type=str, help="Option 1")
myparser.add_argument("--opt2", type=str, required=False, help="Option 2")
myparser.add_argument("-t", "--tags", nargs="*", action=ParseTags)
args = myparser.parse_args()
print(args)

My inspiration for this came from https://sumit-ghosh.com/posts/parsing-dictionary-key-value-pairs-kwargs-argparse-python/ and then I took it a step further to handle multiple key=value pairs separated by spaces and commas and crazy combinations thereof.