rewrite _process_parameter_type in auto_docstring.py to improve usability

src/transformers/utils/auto_docstring.py

@@ -1288,29 +1288,34 @@ def _process_parameter_type(param, param_name, func):
         param_name (`str`): The name of the parameter
         func (`function`): The function the parameter belongs to
     """
-    optional = False
-    if param.annotation != inspect.Parameter.empty:
-        param_type = param.annotation
-        if "typing" in str(param_type):
-            param_type = "".join(str(param_type).split("typing.")).replace("transformers.", "~")
-        elif hasattr(param_type, "__module__"):
-            param_type = f"{param_type.__module__.replace('transformers.', '~').replace('builtins', '')}.{param.annotation.__name__}"
-            if param_type[0] == ".":
-                param_type = param_type[1:]
+    # a parameter for a function might have three basic elements: name, type hint, default value
+    # for example, it would be like (there are some whitespaces)
+    # age: int = 18 (if a param has no type hint, it would be like age=18)
+    parameter_str: str = str(param)
+    # see if there is type hint for given parameter
+    if ":" in parameter_str:
+        name, type_hint_and_default_value = parameter_str.split(":")
+        type_hint_and_default_value = type_hint_and_default_value.strip()
+        if "=" in type_hint_and_default_value:
+            type_hint, default_value = type_hint_and_default_value.split("=")
+            type_hint = type_hint.strip()
+            return type_hint, True
         else:
-            if False:
-                print(
-                    f"[ERROR] {param_type} for {param_name} of {func.__qualname__} in file {func.__code__.co_filename} has an invalid type"
-                )
-        if "ForwardRef" in param_type:
-            param_type = re.sub(r"ForwardRef\('([\w.]+)'\)", r"\1", param_type)
-        if "Optional" in param_type:
-            param_type = re.sub(r"Optional\[(.*?)\]", r"\1", param_type)
-            optional = True
+            type_hint = type_hint_and_default_value
+            type_hint = type_hint.strip()
+            if "Optional" in type_hint:
+                return type_hint, True
+            else:
+                return type_hint, False
     else:
-        param_type = ""
-
-    return param_type, optional
+        # if there is no type hint
+        # see if there is a default value
+        if "=" in parameter_str:
+            # keep this line for debugging, if necessary
+            name, default_value = parameter_str.split("=")
+            return "", True
+        else:
+            return "", False
 
 
 def _get_parameter_info(param_name, documented_params, source_args_dict, param_type, optional):