canonicalize json

util/__init__.py

@@ -1,3 +1,6 @@
+import collections
+
+
 def get_app_url(config):
   """ Returns the application's URL, based on the given config. """
   return '%s://%s' % (config['PREFERRED_URL_SCHEME'], config['SERVER_HOSTNAME'])
@@ -16,3 +19,13 @@ def slash_join(*args):
 
   args = [rmslash(path) for path in args]
   return '/'.join(args)
+
+
+def canonicalize(json_obj):
+  """ Returns a JSON object sorted by key. """
+  if isinstance(json_obj, collections.MutableMapping):
+    sorted_obj = sorted({key: canonicalize(val) for key, val in json_obj}.items())
+    return collections.OrderedDict(sorted_obj)
+  elif isinstance(json_obj, (list, tuple)):
+    return [canonicalize(val) for val in json_obj]
+  return json_obj