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 self._RE_ARRAY_INDEX.match(str(part)):
                raise JsonPointerException("'%s' is not a valid sequence 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 mapping/sequence or support __getitem__" % type(doc))