python - 如何为 click 中的组操作创建异常(exception)

Question

在某些情况下，我想为大多数点击命令运行一个通用函数 (check_upgrade())，但在某些情况下我不想运行它。我不想依赖开发人员记住添加装饰器或函数调用来显式运行此检查，我更愿意默认运行它，然后添加一个可以添加的装饰器(例如 @bypass_upgrade_check ) 对于不应运行 check_upgrade() 的命令。

我希望得到类似的东西:

class State(object):
    def __init__(self):
        self.bypass_upgrade_check = False

pass_state = click.make_pass_decorator(State, ensure=True)

def bypass_upgrade_check(func):
    @pass_state
    def wrapper(state, *args, **kwargs):
        state.bypass_upgrade_check = True
        func(*args, **kwargs)
    return wrapper 

@click.group()
@pass_state
def common(state):
    if not state.bypass_upgrade_check:
        check_upgrade()

@common.command()
def cmd1():
    # check_upgrade() runs here
    pass

@bypass_upgrade_check
@common.command()
def cmd2():
    # don't run check_upgrade() here
    pass

但这行不通。它实际上从未调用 bypass_upgrade_check() 函数。

有没有一种方法可以装饰命令，以便我可以在组代码运行之前修改状态？或者另一种方法可以完成这个任务？

Answer 1

为了跟踪哪些命令绕过升级检查，我建议在绕过标记装饰器中将该状态存储在 click.Command 对象上。然后，如果您将 click.Context 传递给您的组，您就可以查看命令对象以查看它是否被标记为允许跳过升级，例如:

代码:

def bypass_upgrade_check(func):
    setattr(func, 'do_upgrade_check', False)

@click.group()
@click.pass_context
def cli(ctx):
    sub_cmd = ctx.command.commands[ctx.invoked_subcommand]
    if getattr(sub_cmd, 'do_upgrade_check', True):
        check_upgrade()

测试代码:

import click

def check_upgrade():
    click.echo('Checking Upgrade!')

def bypass_upgrade_check(func):
    setattr(func, 'do_upgrade_check', False)

@click.group()
@click.pass_context
def cli(ctx):
    sub_cmd = ctx.command.commands[ctx.invoked_subcommand]
    if getattr(sub_cmd, 'do_upgrade_check', True):
        check_upgrade()

@cli.command()
def cmd1():
    # check_upgrade() runs here
    click.echo('cmd1')

@bypass_upgrade_check
@cli.command()
def cmd2():
    # don't run check_upgrade() here
    click.echo('cmd2')


if __name__ == "__main__":
    commands = (
        'cmd1',
        'cmd2',
    )

    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)
            cli(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)]
-----------
> cmd1
Checking Upgrade!
cmd1
-----------
> cmd2
cmd2