PostgreSQL json_patch(TEXT, TEXT) function using PLPYTHON

json_patch.sql

DROP FUNCTION json_patch(_data TEXT, _patch TEXT)

/*
 * On the PostgreSQL host, you will need to install:
 *     postgresql95-plpython (RedHat/CentOS)
 *     postgresql-plpython-9.5 (Ubuntu/Debian)
 * You will also need to install the jsonpatch library using either easy_install or pip
 *     pip install jsonpatch
 *     easy_install jsonpatch
 */

CREATE EXTENSION plpythonu;

CREATE OR REPLACE FUNCTION json_patch(_data TEXT, _patch TEXT)
RETURNS jsonb
LANGUAGE plpythonu AS
$$
import jsonpatch
import json
patch = jsonpatch.JsonPatch(json.loads(_patch))
return json.dumps(patch.apply(json.loads(_data)))
$$;

SELECT json_patch('{"boo": "baz"}'::TEXT, '[{"op": "add", "path": "/foo", "value": "bar"},{"op": "add", "path": "/baz", "value": [1, 2, 3]},{"op": "remove", "path": "/baz/1"},{"op": "test", "path": "/baz", "value": [1, 3]},{"op": "replace", "path": "/baz/0", "value": 42},{"op": "remove", "path": "/baz/1"}]')