from __future__ import absolute_import, division, unicode_literals
from . import base
from collections import OrderedDict
def _attr_key(attr):
"""Return an appropriate key for an attribute for sorting
Attributes have a namespace that can be either ``None`` or a string. We
can't compare the two because they're different types, so we convert
``None`` to an empty string first.
"""
return (attr[0][0] or ''), attr[0][1]
[docs]class Filter(base.Filter):
"""Alphabetizes attributes for elements"""
def __iter__(self):
for token in base.Filter.__iter__(self):
if token["type"] in ("StartTag", "EmptyTag"):
attrs = OrderedDict()
for name, value in sorted(token["data"].items(),
key=_attr_key):
attrs[name] = value
token["data"] = attrs
yield token