Fix incorrect typing of optional default values

astroid/brain/brain_re.py

@@ -1,5 +1,7 @@
 # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
 # For details: https://github.com/PyCQA/astroid/blob/main/LICENSE
+from typing import Optional
+
 from astroid import context, inference_tip, nodes
 from astroid.brain.helpers import register_module_extender
 from astroid.builder import extract_node, parse
@@ -64,7 +66,9 @@ def _looks_like_pattern_or_match(node: nodes.Call) -> bool:
     )
 
 
-def infer_pattern_match(node: nodes.Call, ctx: context.InferenceContext = None):
+def infer_pattern_match(
+    node: nodes.Call, ctx: Optional[context.InferenceContext] = None
+):
     """Infer re.Pattern and re.Match as classes. For PY39+ add `__class_getitem__`."""
     class_def = nodes.ClassDef(
         name=node.parent.targets[0].name,

astroid/builder.py

@@ -25,7 +25,7 @@
 import textwrap
 import types
 from tokenize import detect_encoding
-from typing import List, Union
+from typing import List, Optional, Union
 
 from astroid import bases, modutils, nodes, raw_building, rebuilder, util
 from astroid._ast import get_parser_module
@@ -82,7 +82,7 @@ def __init__(self, manager=None, apply_transforms=True):
         self._apply_transforms = apply_transforms
 
     def module_build(
-        self, module: types.ModuleType, modname: str = None
+        self, module: types.ModuleType, modname: Optional[str] = None
     ) -> nodes.Module:
         """Build an astroid from a living module instance."""
         node = None

astroid/manager.py

@@ -32,7 +32,7 @@
 import os
 import types
 import zipimport
-from typing import TYPE_CHECKING, ClassVar, List
+from typing import TYPE_CHECKING, ClassVar, List, Optional
 
 from astroid.exceptions import AstroidBuildingError, AstroidImportError
 from astroid.interpreter._import import spec
@@ -268,7 +268,7 @@ def file_from_module_name(self, modname, contextfile):
             raise value.with_traceback(None)
         return value
 
-    def ast_from_module(self, module: types.ModuleType, modname: str = None):
+    def ast_from_module(self, module: types.ModuleType, modname: Optional[str] = None):
         """given an imported module, return the astroid object"""
         modname = modname or module.__name__
         if modname in self.astroid_cache:

astroid/raw_building.py

@@ -106,7 +106,7 @@ def attach_import_node(node, modname, membername):
     _attach_local_node(node, from_node, membername)
 
 
-def build_module(name: str, doc: str = None) -> nodes.Module:
+def build_module(name: str, doc: Optional[str] = None) -> nodes.Module:
     """create and initialize an astroid Module node"""
     node = nodes.Module(name, doc, pure_python=False)
     node.package = False
@@ -304,7 +304,10 @@ def __init__(self, manager_instance=None):
         self._module = None
 
     def inspect_build(
-        self, module: types.ModuleType, modname: str = None, path: str = None
+        self,
+        module: types.ModuleType,
+        modname: Optional[str] = None,
+        path: Optional[str] = None,
     ) -> nodes.Module:
         """build astroid from a living module (i.e. using inspect)
         this is used when there is no python source code available (either