Caching doesn't work that way. Refactor with copy arg in get_type_map

Author: rly

src/pynwb/__init__.py

@@ -101,19 +101,28 @@ def __get_resources() -> dict:
 @docval({'name': 'extensions', 'type': (str, TypeMap, list),
          'doc': 'a path to a namespace, a TypeMap, or a list consisting of paths to namespaces and TypeMaps',
          'default': None},
+        {
+            'name': 'copy', 'type': bool,
+            'doc': 'Whether to return a deepcopy of the TypeMap. '
+            'If False, a direct reference may be returned (use with caution).',
+            'default': True
+        },
         returns="TypeMap loaded for the given extension or NWB core namespace", rtype=tuple,
         is_method=False)
 def get_type_map(**kwargs):
     '''
     Get the TypeMap for the given extensions. If no extensions are provided,
     return the TypeMap for the core namespace
     '''
-    extensions = getargs('extensions', kwargs)
+    extensions, copy_map = getargs('extensions', 'copy', kwargs)
     type_map = None
     if extensions is None:
-        type_map = deepcopy(__TYPE_MAP)
+        if copy_map:
+            type_map = deepcopy(__TYPE_MAP)
+        else:
+            type_map = __TYPE_MAP
     else:
-        warnings.warn("The 'extensions' argument is deprecated and will be removed in HDMF 5.0", DeprecationWarning)
+        warn("The 'extensions' argument is deprecated and will be removed in HDMF 5.0", DeprecationWarning)
         if isinstance(extensions, TypeMap):
             type_map = extensions
         else:

src/pynwb/core.py

@@ -32,8 +32,6 @@ class NWBMixin(AbstractContainer):
 
     __nwbfields__ = tuple()
 
-    __type_map = None
-
     @docval({'name': 'neurodata_type', 'type': str, 'doc': 'the data_type to search for', 'default': None})
     def get_ancestor(self, **kwargs):
         """
@@ -63,11 +61,7 @@ def _error_on_new_pass_on_construct(self, error_msg: str):
             raise ValueError(error_msg)
 
     def _get_type_map(self):
-        # Cache the type map to avoid repeated calls to get_type_map()
-        if self.__type_map is None:
-            self.__type_map = get_type_map()
-
-        return self.__type_map
+        return get_type_map(copy=False)
 
     @property
     def data_type(self):