[Python] deserialize enum json response (fix #17789) (#17791)

* deserialize enum json response (python)

* adapt python samples: adding enum deserialization

* add echo test for enum json response deserialization (python)

* update samples

samples/openapi3/client/petstore/python/petstore_api/api_client.py

@@ -14,6 +14,7 @@
 
 import datetime
 from dateutil.parser import parse
+from enum import Enum
 import json
 import mimetypes
 import os
@@ -429,6 +430,8 @@ class ApiClient:
             return self.__deserialize_date(data)
         elif klass == datetime.datetime:
             return self.__deserialize_datetime(data)
+        elif issubclass(klass, Enum):
+            return self.__deserialize_enum(data, klass)
         else:
             return self.__deserialize_model(data, klass)
 
@@ -733,6 +736,24 @@ class ApiClient:
                 )
             )
 
+    def __deserialize_enum(self, data, klass):
+        """Deserializes primitive type to enum.
+
+        :param data: primitive type.
+        :param klass: class literal.
+        :return: enum value.
+        """
+        try:
+            return klass(data)
+        except ValueError:
+            raise rest.ApiException(
+                status=0,
+                reason=(
+                    "Failed to parse `{0}` as `{1}`"
+                    .format(data, klass)
+                )
+            )
+
     def __deserialize_model(self, data, klass):
         """Deserializes list or dict to model.