I used to do this, but now I use jq. The thing about the Python version is that Python doesn't have ordered dictionaries, so the output isn't in the same order as the raw JSON. jq doesn't have that issue which is nice.
One liner-wise, you could create an alias
echo '{"foo":12, "bar": 11}' | python -c 'import json as j, collections as c, sys as s; j.dump(j.load(s.stdin, object_pairs_hook=c.OrderedDict), s.stdout, indent=4)'