jsonpointer.py 文件源码

def get_part(self, doc, part):
        """ Returns the next step in the correct type """

        if isinstance(doc, Mapping):
            return part

        elif isinstance(doc, Sequence):

            if part == '-':
                return part

            if not RE_ARRAY_INDEX.match(str(part)):
                raise JsonPointerException("'%s' is not a valid list index" % (part, ))

            return int(part)

        elif hasattr(doc, '__getitem__'):
            # Allow indexing via ducktyping if the target has defined __getitem__
            return part

        else:
            raise JsonPointerException("Document '%s' does not support indexing, "
                                       "must be dict/list or support __getitem__" % type(doc))