[python-server] Support python 3.7 for all server-generators (#2884)

* Support python 3.7 for all server-generators

Signed-off-by: Guillaume Smaha <guillaume.smaha@gmail.com>

* Rename typing_patch.py to typing_utils.py

* Renaming typing_patch.mustache to typing_utils.mustache

* Fix comparaison in typing_utils.is_dict for python3.7

samples/server/petstore/python-blueplanet/app/openapi_server/typing_utils.py

@@ -0,0 +1,32 @@
+# coding: utf-8
+
+import sys
+
+if sys.version_info < (3, 7):
+    import typing
+
+    def is_generic(klass):
+        """ Determine whether klass is a generic class """
+        return type(klass) == typing.GenericMeta
+
+    def is_dict(klass):
+        """ Determine whether klass is a Dict """
+        return klass.__extra__ == dict
+
+    def is_list(klass):
+        """ Determine whether klass is a List """
+        return klass.__extra__ == list
+
+else:
+
+    def is_generic(klass):
+        """ Determine whether klass is a generic class """
+        return hasattr(klass, '__origin__')
+
+    def is_dict(klass):
+        """ Determine whether klass is a Dict """
+        return klass.__origin__ == dict
+
+    def is_list(klass):
+        """ Determine whether klass is a List """
+        return klass.__origin__ == list

samples/server/petstore/python-blueplanet/app/openapi_server/util.py

@@ -2,6 +2,7 @@ import datetime
 
 import six
 import typing
+from openapi_server import typing_utils
 
 
 def _deserialize(data, klass):
@@ -23,10 +24,10 @@ def _deserialize(data, klass):
         return deserialize_date(data)
     elif klass == datetime.datetime:
         return deserialize_datetime(data)
-    elif type(klass) == typing.GenericMeta:
-        if klass.__extra__ == list:
+    elif typing_utils.is_generic(klass):
+        if typing_utils.is_list(klass):
             return _deserialize_list(data, klass.__args__[0])
-        if klass.__extra__ == dict:
+        if typing_utils.is_dict(klass):
             return _deserialize_dict(data, klass.__args__[1])
     else:
         return deserialize_model(data, klass)