如何在 Python3 中使用 argparse 从两组命令行参数中解析出一组？

Question

我想开发一个 CLI，将两对参数中的一个参数放在一起：

group-resources --limit 5

或

group-overlap --groups group1,group2

组资源是位置性的，需要限制。其余两者的规则相同。但是，我当前的代码强制要求全部四个。

我当前的代码：

import argparse

import analysis
import cleanup
import etl
import initialize_db

parser = argparse.ArgumentParser(
    description='Inventory DB for Cloud Infrastructure')
parser.add_argument(
    'group-resources', help='List top k groups as per their memory, disk, and cpu count.')
parser.add_argument(
    '--limit', help='Number of groups in descending order of their resources.', type=int, required=True)
parser.add_argument(
    'group-overlap', help='Fetch nodes that belong in both the groups')
parser.add_argument(
    '--groups', help='specify the group names separated by a comma.', type=str, required=True
)

args = parser.parse_args()

print(args)

当我运行 python3 cli.py group-resources --limit 5 时，出现以下错误：

usage: cli.py [-h] --limit LIMIT --groups GROUPS group-resources group-overlap
cli.py: error: the following arguments are required: group-overlap, --groups

我希望如果我提供组资源和限制，或者如果我提供组重叠和组，那么我的代码应该可以工作。不允许有其他排列。我该怎么做？

Answer 1

我们可以使用subparsers。以下是我们如何对您的代码进行轻微修改。

import argparse

parser = argparse.ArgumentParser(
    description='Inventory DB for Cloud Infrastructure')

subparsers = parser.add_subparsers(help='types of arguments')

group_resources_parser = subparsers.add_parser("group-resources", help='List top k groups as per their memory, disk, and cpu count.')
group_overlap_parser = subparsers.add_parser("group-overlap", help='Fetch nodes that belong in both the groups')
group_resources_parser.add_argument(
    '--limit', help='Number of groups in descending order of their resources.', type=int, required=True)
group_overlap_parser.add_argument(
    '--groups', help='specify the group names separated by a comma.', type=str, required=True
)

args = parser.parse_args()

print(args)

示例：

python3 cli.py group-resources

  usage: cli.py group-resources [-h] --limit LIMIT
  cli.py group-resources: error: the following arguments are required: --limit

python3 cli.py group-overlap

 usage: cli.py group-overlap [-h] --groups GROUPS
 cli.py group-overlap: error: the following arguments are required: --groups

python3 cli.py group-resources --limit 5 group-overlap

  usage: cli.py [-h] {group-resources,group-overlap} ...
  cli.py: error: unrecognized arguments: group-overlap

如何在 Python3 中使用 argparse 从两组命令行参数中解析出一组？

How to parse one group out of the two groups of command line arguments using argparse in Python3?

python

command-line-interface

argparse

python-3.x