使用Python click命令调用具有可变参数的类方法

Question

我有一个类，该类使用以前未知数量的参数进行初始化，我希望使用Python的click包在CLI上完成初始化。我的问题是我无法初始化它并运行click命令：

$ python mycode.py arg1 arg2 ... argN click_command

设置定义数量的参数，如nargs=5，可以解决缺少命令的问题，但我必须在命令之前输入5个参数。对于变量参数nargs=-1，click不将click_command识别为命令

如何输入n个参数，然后使用click运行命令

import click

class Foo(object):
    def __init__(self, *args):
        self.args = args

    def log(self):
        print('self.args:', self.args)

pass_foo = click.make_pass_decorator(Foo)

@click.group()
@click.argument('myargs', nargs=-1)
@click.pass_context
def main(ctx, myargs):
    ctx.obj = Foo(myargs)
    print("arguments: ", myargs)

@main.command()
@pass_foo
def log(foo):
    foo.log()

main()

我希望能够在向我的Foo()类传递n个参数后运行click命令，这样我就可以初始化它并将其log()方法作为CLI命令运行，但输出是：

Error: Missing command

Answer 1

我不完全确定你试图做的是解决这个问题的最佳方式。我认为将变量参数放在命令后面会更符合逻辑，并且肯定会更符合单击的工作方式。但是，您可以通过以下方式实现您的目标：

自定义类：

class CommandAfterArgs(click.Group):

    def parse_args(self, ctx, args):
        parsed_args = super(CommandAfterArgs, self).parse_args(ctx, args)
        possible_command = ctx.params['myargs'][-1]
        if possible_command in self.commands:
            ctx.protected_args = [possible_command]
            ctx.params['myargs'] = ctx.params['myargs'][:-1]

        elif possible_command in ('-h', ' help'):
            if len(ctx.params['myargs']) > 1 and \
                    ctx.params['myargs'][-2] in self.commands:
                ctx.protected_args = [ctx.params['myargs'][-2]]
                parsed_args = [' help']
                ctx.params['myargs'] = ctx.params['myargs'][:-2]
                ctx.args = [possible_command]

        return parsed_args

使用自定义类：

然后，要使用自定义类，请将其作为cls参数传递给组装饰器，如：

@click.group(cls=CommandAfterArgs)
@click.argument('myargs', nargs=-1)
def main(myargs):
    ...

测试代码：

import click

class Foo(object):
    def __init__(self, *args):
        self.args = args

    def log(self):
        print('self.args:', self.args)


pass_foo = click.make_pass_decorator(Foo)


@click.group(cls=CommandAfterArgs)
@click.argument('myargs', nargs=-1)
@click.pass_context
def main(ctx, myargs):
    ctx.obj = Foo(*myargs)
    print("arguments: ", myargs)


@main.command()
@pass_foo
def log(foo):
    foo.log()


if __name__ == "__main__":
    commands = (
        'arg1 arg2 log',
        'log  help',
        ' help',
    )

    import sys, time

    time.sleep(1)
    print('Click Version: {}'.format(click.__version__))
    print('Python Version: {}'.format(sys.version))
    for cmd in commands:
        try:
            time.sleep(0.1)
            print('     -')
            print('> ' + cmd)
            time.sleep(0.1)
            main(cmd.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)]
     -
> arg1 arg2 log
arguments:  ('arg1', 'arg2')
self.args: ('arg1', 'arg2')
     -
> log  help
arguments:  ()
Usage: test.py log [OPTIONS]

Options:
   help  Show this message and exit.
     -
>  help
Usage: test.py [OPTIONS] [MYARGS]... COMMAND [ARGS]...

Options:
   help  Show this message and exit.

Commands:
  log