refactor to simplify

Author: willmcgugan

src/textual/app.py

@@ -3698,6 +3698,13 @@ def action_help_quit(self) -> None:
                 )
                 return
 
+    @classmethod
+    def _normalize_keymap(cls, keymap: Keymap) -> Keymap:
+        """Normalizes the keys in a keymap, so they use long form, i.e. "question_mark" rather than "?"."""
+        return {
+            binding_id: _normalize_key_list(keys) for binding_id, keys in keymap.items()
+        }
+
     def set_keymap(self, keymap: Keymap) -> None:
         """Set the keymap, a mapping of binding IDs to key strings.
 
@@ -3711,9 +3718,7 @@ def set_keymap(self, keymap: Keymap) -> None:
             keymap: A mapping of binding IDs to key strings.
         """
 
-        self._keymap = {
-            binding_id: _normalize_key_list(keys) for binding_id, keys in keymap.items()
-        }
+        self._keymap = self._normalize_keymap(keymap)
         self.refresh_bindings()
 
     def update_keymap(self, keymap: Keymap) -> None:
@@ -3725,10 +3730,8 @@ def update_keymap(self, keymap: Keymap) -> None:
         Args:
             keymap: A mapping of binding IDs to key strings.
         """
-        keymap = {
-            binding_id: _normalize_key_list(keys) for binding_id, keys in keymap.items()
-        }
-        self._keymap = {**self._keymap, **keymap}
+
+        self._keymap = {**self._keymap, **self._normalize_keymap(keymap)}
         self.refresh_bindings()
 
     def handle_bindings_clash(