如果你想在一个入口命令中访问多个子cli，你可以在__main__.py处实现一个子命令管理器，它可以从sys.argv解析子命令，然后分发到目标模块。

1️⃣首先，我推荐https://github.com/google/python-fire/blob/master/docs/guide.md，不需要额外的代码，大部分场景都能满足你。

这里是一个例子，你可以使用 from command1 import xx 替换你的子命令函数的加法/乘法函数，并使用入口点来暴露主函数。

import fire

def add(x, y):
  return x + y

def multiply(x, y):
  return x * y


def main():
  fire.Fire({
      'add': add,
      'multiply': multiply,
  })

if __name__ == '__main__':
  main()

我们可以通过以下相同的方式进行调试：

$ python example.py add 10 20
30
$ python example.py multiply 10 20
200

2️⃣其次，如果您出于某种目的需要自己实现，例如使用argparse为每个命令定义选项。一个典型的做法是https://github.com/django/django/blob/main/django/core/management/base.py#L173，官方demo：https://docs.djangoproject.com/en/3.2/howto/custom-management-commands/

核心步骤是：

1. 定义一个 BaseCommand
2. 在子commands.py中实现BaseCommand，命名为Command。
3. __main__.py 实现 find 命令和调用

# base_command.py
class BaseCommand(object):
    def create_parser(self, prog_name, subcommand, **kwargs):
        """
        Create and return the ``ArgumentParser`` which will be used to
        parse the arguments to this command.
        """
        # TODO: create your ArgumentParser
        return CommandParser(**kwargs) 
        
    def add_arguments(self, parser):
        """
        Entry point for subclassed commands to add custom arguments.
        """
        pass

    def run_from_argv(self, argv):
        """
        Entry point for commands to be run from the command line.
        """
        parser = self.create_parser(argv[0], argv[1])
        options = parser.parse_args(argv[2:])
        cmd_options = vars(options)
        args = cmd_options.pop('args', ())
        self.handle(*args, **cmd_options)
    
    def handle(self, *args, **options):
        """
        The actual logic of the command. Subclasses must implement
        this method.
        """
        raise NotImplementedError('subclasses of BaseCommand must provide a handle() method')
    
    
# command1.py     
class Command(BaseCommand):
    def handle(self, *args, **options):
        print("Hello, it is command1!")
        
   
# command2.py     
class Command(BaseCommand):
    def handle(self, *args, **options):
        print("Hello, it is command2!")
        
    
# __main__.py         
def main():
    # sub command name is the second argument
    command_name = sys.argv[1]
    # build sub command module name, and import
    # package-name is the module name you mentioned
    cmd_package_name = f'package-name.{command_name}'
    instance = importlib.import_module(cmd_package_name)
    # create instance of sub command, the Command must exist
    command = instance.Command()
    command.run_from_argv(sys.argv)

if __name__ == "__main__":
    main()