python - 为什么我使用 click.argument 会产生 "got an unexpected keyword argument ' 帮助？

Question

运行以下代码会导致此错误:

TypeError: init() got an unexpected keyword argument 'help'

代码:

import click

@click.command()
@click.argument('command', required=1, help="start|stop|restart")
@click.option('--debug/--no-debug', default=False, help="Run in foreground")
def main(command, debug):
    print (command)
    print (debug)

if __name__ == '__main__':
    main()

完整的错误输出:

$ python3 foo.py start
Traceback (most recent call last):
  File "foo.py", line 5, in <module>
    @click.option('--debug/--no-debug', default=False, help="Run in foreground")
  File "/home/cbetti/python/lib/python3/dist-packages/click-4.0-py3.4.egg/click/decorators.py", line 148, in decorator
    _param_memo(f, ArgumentClass(param_decls, **attrs))
  File "/home/cbetti/python/lib/python3/dist-packages/click-4.0-py3.4.egg/click/core.py", line 1618, in __init__
    Parameter.__init__(self, param_decls, required=required, **attrs)
TypeError: __init__() got an unexpected keyword argument 'help'

为什么会出现这个错误？

Answer 1

我一次又一次地遇到这个问题，因为跟踪输出与导致错误的参数不对应。注意跟踪中的 ArgumentClass，这是您的提示。

'help' 是 @click.option 可接受的参数。但是，点击库更喜欢您记录自己的论点。 @click.argument help 参数导致此异常。

此代码有效:(注意 @click.argument 中缺少 , help="start|stop|restart")

import click

@click.command()
@click.argument('command', required=1)
@click.option('--debug/--no-debug', default=False, help="Run in foreground")
def main(command, debug):
    """ COMMAND: start|stop|restart """
    print (command)
    print (debug)

if __name__ == '__main__':
        main()

输出:

$ python3 foo.py start
start
False

帮助输出:

Usage: test.py [OPTIONS] COMMAND

  COMMAND: start|stop|restart

Options:
  --debug / --no-debug  Run in foreground
  --help                Show this message and exit.