constructor.py 文件源码

def construct_mapping(self, node, deep=False):
        if not isinstance(node, nodes.MappingNode):
            raise ConstructorError(
                None, None,
                'expected a mapping node, but found %s' % node.id,
                node.start_mark
            )
        mapping = {}
        for key_node, value_node in node.value:
            key = self.construct_object(key_node, deep=deep)
            if not isinstance(key, collections.Hashable):
                self.echoerr(
                    'While constructing a mapping', node.start_mark,
                    'found unhashable key', key_node.start_mark
                )
                continue
            elif type(key.value) != unicode:
                self.echoerr(
                    'Error while constructing a mapping', node.start_mark,
                    'found key that is not a string', key_node.start_mark
                )
                continue
            elif key in mapping:
                self.echoerr(
                    'Error while constructing a mapping', node.start_mark,
                    'found duplicate key', key_node.start_mark
                )
                continue
            value = self.construct_object(value_node, deep=deep)
            mapping[key] = value
        return mapping