python argparse父处理器中的common_exclusive_group和add_argument_group吗? [英] python argparse mutually_exclusive_group and add_argument_group in a parent processor?

问题描述

我不确定是否找到了argparse错误，或者我是否很钝. 我研究了#45602511 在顶级案例中发现它有效".

I'm not sure if I've found an argparse bug, or if I'm being obtuse. I researched #45602511 which is how I found it "works" in the top-level case.

我正在尝试使用arguments_group分离出一些格式设置选项(碰巧是互斥的).如果事情在解析器结构的顶层，则可以将mutually_exclusive_group嵌套在argument_group下，并且可以得到期望的帮助行为:

I'm trying to use an argument_group to separate out some formatting options (which happen to be mutually exclusive). If things are at the top level of the parser structure, I can nest a mutually_exclusive_group under an argument_group and I get the help behavior I'm expecting:

以下代码在Python 3.6.2中可以正常工作:

The following code works fine in Python 3.6.2:

import argparse

parser = argparse.ArgumentParser()
commands = parser.add_subparsers()
hit = commands.add_parser('hit')
miss = commands.add_parser('miss')

parser.add_argument('--summary', action='store_true', help='summarize information')
parser.add_argument('--verbose', action='store_true', help='tell us more')

output_format = parser.add_argument_group("Output format")
styles = output_format.add_mutually_exclusive_group()
styles.add_argument('--plain', dest='style')
styles.add_argument('--green', dest='style')
styles.add_argument('--blue', dest='style')

print(parser.parse_args(['-h']))

它将生成以下输出:

usage: baz.py [-h] [--summary] [--verbose]
              [--plain STYLE | --green STYLE | --blue STYLE]
              {hit,miss} ...

positional arguments:
  {hit,miss}

optional arguments:
  -h, --help     show this help message and exit
  --summary      summarize information
  --verbose      tell us more

Output format:
  --plain STYLE
  --green STYLE
  --blue STYLE

但是，我实际上需要一个用于子解析器的帮助代码，而不是顶级的，所以我的代码看起来确实像这样，而argparse忽略了arguments_group嵌套:

However, I actually need this help code for a subparser, not at the top level, so my code really looks like this, and argparse ignores the argument_group nesting:

global_options = argparse.ArgumentParser(add_help=False)
global_options.add_argument('--summary', action='store_true', help='summarize information')
global_options.add_argument('--verbose', action='store_true', help='tell us more')

output_format = global_options.add_argument_group("Output format", "ways to foo")
styles = output_format.add_mutually_exclusive_group()
styles.add_argument('--plain', dest='style')
styles.add_argument('--green', dest='style')
styles.add_argument('--blue', dest='style')

parser = argparse.ArgumentParser()
commands = parser.add_subparsers()
hit = commands.add_parser('hit', parents=[global_options])
miss = commands.add_parser('miss', parents=[global_options])

print(parser.parse_args(['hit', '-h']))

生产:

usage: bar.py hit [-h] [--summary] [--verbose]
                  [--plain STYLE | --green STYLE | --blue STYLE]

optional arguments:
  -h, --help     show this help message and exit
  --summary      summarize information
  --verbose      tell us more
  --plain STYLE
  --green STYLE
  --blue STYLE

Output format:
  ways to foo

我做错了什么，还是argparse坏了?

Am I doing something wrong, or is argparse broken?

推荐答案

这个在parents中嵌套的互斥组的问题已在几个bug/问题中引起.

This problem of a nested mutually exclusive group in a parents has been raised in a couple of bug/issues.

http://bugs.python.org/issue25882 ，(argparse help error: arguments created by add_mutually_exclusive_group() are shown outside their parent group created by add_argument_group())

和

http://bugs.python.org/issue16807 ，(argparse group nesting lost on inheritance)

在参数组中嵌套一个互斥的组是可行的，但没有记录.但是在单元测试文件中有一个这样的例子， http://bugs.python.org/issue17218，(support title and description in argparse add_mutually_exclusive_group)

Nesting a mutually exclusive group in an argument group works, but isn't documented. But there is an example of this in the unittesting file, http://bugs.python.org/issue17218, (support title and description in argparse add_mutually_exclusive_group)

通过parser._add_container_actions方法处理从parents复制组和动作. parents机制适用于简单的解析器，但使用率不高，也不可靠.

Copying groups and actions from a parents is handled by parser._add_container_actions method. The parents mechanism works fine for simple parsers, but it is not heavily used nor is it robust.

示例子解析器创建功能

def make_subparser(commands, name):
  sub = commands.add_parser(name)
  sub.add_argument('--summary', action='store_true', help='summarize information')
  sub.add_argument('--verbose', action='store_true', help='tell us more')
  output_format = sub.add_argument_group("Output format", "ways to foo")
  styles = output_format.add_mutually_exclusive_group()
  styles.add_argument('--plain', dest='style')
  styles.add_argument('--green', dest='style')
  styles.add_argument('--blue', dest='style')
return sub

parser = argparse.ArgumentParser()
commands = parser.add_subparsers()
hit = make_subparser(commands,'hit')
miss = make_subparser(commands 'miss')

这篇关于python argparse父处理器中的common_exclusive_group和add_argument_group吗?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！