@@ -2128,9 +2128,11 @@ def to_api_repr(self):
 return self._properties
 
 def _key(self):
+# because we are only "renaming" top level keys shallow copy is sufficient here.
 properties = self._properties.copy()
 if "type" in properties.keys():
-properties["type_"] = properties.pop("type")
+# calling repr for non built-in type objects.
+properties["type_"] = repr(properties.pop("type"))
 if "requirePartitionFilter" in properties.keys():
 properties["require_partition_filter"] = properties.pop("requirePartitionFilter")
 if "expirationMs" in properties.keys():
@@ -2149,7 +2151,7 @@ def __hash__(self):
 return hash(self._key())
 
 def __repr__(self):
-key_vals = ["{}={}".format(key, repr(val)) for key, val in self._key()]
+key_vals = ["{}={}".format(key, val) for key, val in self._key()]
 return "TimePartitioning({})".format(",".join(key_vals))