context.py 文件源码

def _get_literal_value(self, literal):
        '''Utility function to turn AST literals into native Python types

        :param literal: The AST literal to convert
        :return: The value of the AST literal
        '''
        if isinstance(literal, _ast.Num):
            literal_value = literal.n

        elif isinstance(literal, _ast.Str):
            literal_value = literal.s

        elif isinstance(literal, _ast.List):
            return_list = list()
            for li in literal.elts:
                return_list.append(self._get_literal_value(li))
            literal_value = return_list

        elif isinstance(literal, _ast.Tuple):
            return_tuple = tuple()
            for ti in literal.elts:
                return_tuple = return_tuple + (self._get_literal_value(ti),)
            literal_value = return_tuple

        elif isinstance(literal, _ast.Set):
            return_set = set()
            for si in literal.elts:
                return_set.add(self._get_literal_value(si))
            literal_value = return_set

        elif isinstance(literal, _ast.Dict):
            literal_value = dict(zip(literal.keys, literal.values))

        elif isinstance(literal, _ast.Ellipsis):
            # what do we want to do with this?
            literal_value = None

        elif isinstance(literal, _ast.Name):
            literal_value = literal.id

        # NOTE(sigmavirus24): NameConstants are only part of the AST in Python
        # 3. NameConstants tend to refer to things like True and False. This
        # prevents them from being re-assigned in Python 3.
        elif six.PY3 and isinstance(literal, _ast.NameConstant):
            literal_value = str(literal.value)

        # NOTE(sigmavirus24): Bytes are only part of the AST in Python 3
        elif six.PY3 and isinstance(literal, _ast.Bytes):
            literal_value = literal.s

        else:
            literal_value = None

        return literal_value