Fix typing errors for python 3.7

Author: Tinitto

.gitignore

@@ -142,3 +142,5 @@ cython_debug/
 .benchmarks/
 
 .python-version
+
+env3.7/

pydantic_redis/model.py

@@ -50,25 +50,27 @@ def initialize(cls):
                 is_generic = hasattr(field_type, "__origin__")
                 if (
                     is_generic
-                    and field_type.__origin__ == Union
-                    and field_type.__args__[-1] == None.__class__
+                    and typing_get_origin(field_type) == Union
+                    and typing_get_args(field_type)[-1] == None.__class__
                 ):
-                    field_type = field_type.__args__[0]
+                    field_type = typing_get_args(field_type)[0]
                     is_generic = hasattr(field_type, "__origin__")
 
                 if (
                     is_generic
-                    and field_type.__origin__ == List
-                    and issubclass(field_type.__args__[0], Model)
+                    and typing_get_origin(field_type) in (List, list)
+                    and issubclass(typing_get_args(field_type)[0], Model)
                 ):
-                    cls._nested_model_list_fields[field] = field_type.__args__[0]
+                    cls._nested_model_list_fields[field] = typing_get_args(field_type)[
+                        0
+                    ]
 
                 elif (
                     is_generic
-                    and field_type.__origin__ == Tuple
-                    and any([issubclass(v, Model) for v in field_type.__args__])
+                    and typing_get_origin(field_type) in (Tuple, tuple)
+                    and any([issubclass(v, Model) for v in typing_get_args(field_type)])
                 ):
-                    cls._nested_model_tuple_fields[field] = field_type.__args__
+                    cls._nested_model_tuple_fields[field] = typing_get_args(field_type)
 
                 elif issubclass(field_type, Model):
                     cls._nested_model_fields[field] = field_type
@@ -401,7 +403,7 @@ def __get_select_fields(cls, columns: Optional[List[str]]) -> Optional[List[str]
             if isinstance(field_type, type(Model)):
                 fields.append(f"{NESTED_MODEL_PREFIX}{col}")
             elif issubclass(field_type, List) and isinstance(
-                field_type.__args__[0], type(Model)
+                typing_get_args(field_type)[0], type(Model)
             ):
                 fields.append(f"{NESTED_MODEL_LIST_FIELD_PREFIX}{col}")
             else:
@@ -487,3 +489,19 @@ def strip_leading(word: str, substring: str) -> str:
     if word.startswith(substring):
         return word[len(substring) :]
     return word
+
+
+def typing_get_args(v: Any) -> Tuple[Any, ...]:
+    """Gets the __args__ of the annotations of a given typing"""
+    try:
+        return typing.get_args(v)
+    except AttributeError:
+        return getattr(v, "__args__", ()) if v is not typing.Generic else typing.Generic
+
+
+def typing_get_origin(v: Any) -> Optional[Any]:
+    """Gets the __origin__ of the annotations of a given typing"""
+    try:
+        return typing.get_origin(v)
+    except AttributeError:
+        return getattr(v, "__origin__", None)