从ArgumentParser获取允许的参数的正确方法 [英] Correct way to get allowed arguments from ArgumentParser

问题描述

问题:从现有的argparse.ArgumentParser对象访问可能的参数的预期/正式方式是什么?

Question: What is the intended / official way of accessing possible arguments from an existing argparse.ArgumentParser object?

示例:让我们假设以下上下文:

Example: Let's assume the following context:

import argparse
parser = argparse.ArgumentParser()
parser.add_argument('--foo', '-f', type=str)

在这里，我想获得以下允许的参数列表:

Here I'd like to get the following list of allowed arguments:

['-h', '--foo', '--help', '-f']

我发现以下变通办法可以帮我解决问题

I found the following workaround which does the trick for me

parser._option_string_actions.keys()

但是我对此不满意，因为它涉及访问未正式记录的_成员.什么是此任务的正确替代方法?

But I'm not happy with it, as it involves accessing a _-member that is not officially documented. Whats the correct alternative for this task?

推荐答案

我认为没有一种更好"的方式来实现您想要的目标.

I don't think there is a "better" way to achieve what you want.

如果您真的不想使用_option_string_actions属性，则可以处理parser.format_usage()来检索选项，但是这样做，您只会得到简短的选项名称.

If you really don't want to use the _option_string_actions attribute, you could process the parser.format_usage() to retrieve the options, but doing this, you will get only the short options names.

如果同时需要短名称和长名称，则可以处理parser.format_help().

If you want both short and long options names, you could process the parser.format_help() instead.

可以使用非常简单的正则表达式来完成此过程:-+\w+

This process can be done with a very simple regular expression: -+\w+

import re

OPTION_RE = re.compile(r"-+\w+")
PARSER_HELP = """usage: test_args_2.py [-h] [--foo FOO] [--bar BAR]

optional arguments:
  -h, --help         show this help message and exit
  --foo FOO, -f FOO  a random options
  --bar BAR, -b BAR  a more random option
"""

options = set(OPTION_RE.findall(PARSER_HELP))

print(options)
# set(['-f', '-b', '--bar', '-h', '--help', '--foo'])

---

或者您可以首先制作一个包含参数解析器配置的字典，然后从中构建argmuent解析器.这样的词典可以将选项名称作为键，将选项配置作为值.这样做，您可以通过使用

如果我不愿意使用_option_string_actions，这是我会做的最后一件事.

This last way is what I would do, if I was reluctant to use _option_string_actions.

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