command.py 文件源码

def __init__(self, parameter, position, type_=None):
        default = parameter.default
        empty = parameter.empty
        self._parameter = parameter

        self.is_positional = default is empty
        self.is_optional = not self.is_positional
        self.is_keyword_only = self.kind is parameter.KEYWORD_ONLY

        if type_ is not None:
            self.type = type_
            self.is_bool = issubclass(type_, bool)
            self.is_dict = issubclass(type_, dict)
            self.is_enum = issubclass(type_, Enum)
            self.is_list = issubclass(type_, (list, tuple))
        else:
            self.type = str if default in (None, empty) else type(default)
            self.is_bool = isinstance(default, bool)
            self.is_dict = isinstance(default, dict)
            self.is_enum = isinstance(default, Enum)
            self.is_list = isinstance(default, (list, tuple))

        self.position = position
        self.takes_value = self.is_positional or (self.is_optional and not self.is_bool)