Why isn't fromfile-prefix-chars in Python argparse working?

Question

I\'m trying to use the fromfile-prefix-chars feature of argparse in Python to load all my command line arguments from a file, but it keeps complaining that I haven\'t specif

Answer 1

Try to this way

# encoding: utf-8
import imp
import argparse


class LoadConfigAction(argparse._StoreAction):
    NIL = object()

    def __init__(self, option_strings, dest, **kwargs):
        super(self.__class__, self).__init__(option_strings, dest)
        self.help = "Load configuration from file"

    def __call__(self, parser, namespace, values, option_string=None):
        super(LoadConfigAction, self).__call__(parser, namespace, values, option_string)

        config = imp.load_source('config', values)

        for key in (set(map(lambda x: x.dest, parser._actions)) & set(dir(config))):
            setattr(namespace, key, getattr(config, key))

Usage

parser.add_argument("-C", "--config", action=LoadConfigAction, default=None)
parser.add_argument("-H", "--host")

Example config (real is python file)

# Config example /etc/my.conf
import os

# Parameter definition
host = os.getenv("HOST", "127.0.0.1")