如何处理小组帮助消息

时间:2019-03-01 21:41:15

标签: python command-line-interface python-click

我试图了解有关Click的一些实施细节。我有以下示例代码:

#cli.py

import click


@click.group()
def cli():
    pass


@cli.group()
def show():
    """ Define the environment of the product """
    pass


@show.command()
def name():
    click.echo("run show name command")


@show.command()
def height():
    click.echo("run show height command")


if __name__ == "__main__":
    cli()

使用此代码,nameheightshow组的子 命令 。但是,从语义上讲,这实际上没有任何意义。它们更像是“显示”命令的 参数

我知道我可以拥有一个带有“属性”参数的命令,通过该命令,我可以基于“属性”的字符串值调用其他函数。但是,我认为一旦存在“属性”的几种可能性,维护起来就很麻烦。

如果可以编辑帮助消息,我相信我仍然可以使用上面的结构。运行cli.py show --help时,会获得命令组的默认帮助消息:

Usage: cli.py show [OPTIONS] COMMAND [ARGS]...

  Define the environment of the product

Options:
  --help  Show this message and exit.

Commands:
  height
  name

是否可以编辑帮助消息,以将“命令”更改为“参数”?我知道如何在click.group()装饰器中更改用法声明,但不确定如何修改帮助消息本身。

我想获得的帮助信息如下:

Usage: cli.py show [OPTIONS] ARG

  Define the environment of the product

Options:
  --help  Show this message and exit.

Arguments:
  height
  name

这样可能吗?

我正在使用python3和Click 6.7

1 个答案:

答案 0 :(得分:0)

您可以通过使用组的自定义类来更改子命令help给出的消息。可以通过从click.Group继承并更改format_commands()方法来制成自定义类,例如:

自定义类别:

class HelpAsArgs(click.Group):
    # change the section head of sub commands to "Arguments"

    def format_commands(self, ctx, formatter):
        rows = []
        for subcommand in self.list_commands(ctx):
            cmd = self.get_command(ctx, subcommand)
            if cmd is None:
                continue

            help = cmd.short_help or ''
            rows.append((subcommand, help))

        if rows:
            with formatter.section('Arguments'):
                formatter.write_dl(rows)

测试代码:

import click

@click.group()
def cli():
    pass

@cli.group(cls=HelpAsArgs)
def show():
    """ Define the environment of the product """
    pass

@show.command()
def name():
    click.echo("run show name command")

@show.command()
def height():
    click.echo("run show height command")

if __name__ == "__main__":
    commands = (
        'show',
        'show --help',
        '--help',
    )

    import sys, time

    time.sleep(1)
    print('Click Version: {}'.format(click.__version__))
    print('Python Version: {}'.format(sys.version))
    for command in commands:
        try:
            time.sleep(0.1)
            print('-----------')
            print('> ' + command)
            time.sleep(0.1)
            cli(command.split())

        except BaseException as exc:
            if str(exc) != '0' and \
                    not isinstance(exc, (click.ClickException, SystemExit)):
                raise

结果:

Click Version: 6.7
Python Version: 3.6.3 (v3.6.3:2c5fed8, Oct  3 2017, 18:11:49) [MSC v.1900 64 bit (AMD64)]
-----------
> show
Usage: test.py show [OPTIONS] COMMAND [ARGS]...

  Define the environment of the product

Options:
  --help  Show this message and exit.

Arguments:
  height
  name
-----------
> show --help
Usage: test.py show [OPTIONS] COMMAND [ARGS]...

  Define the environment of the product

Options:
  --help  Show this message and exit.

Arguments:
  height
  name
-----------
> --help
Usage: test.py [OPTIONS] COMMAND [ARGS]...

Options:
  --help  Show this message and exit.

Commands:
  show  Define the environment of the product