typing

src/ifcopenshell-python/ifcopenshell/entity_instance.py

@@ -26,7 +26,7 @@ import operator
 import subprocess
 import sys
 import time
-from typing import Union, Any, TypeVar, overload, TYPE_CHECKING
+from typing import Union, Any, TypeVar, overload, TYPE_CHECKING, cast, NoReturn
 from collections.abc import Callable, Sequence
 
 from . import ifcopenshell_wrapper
@@ -64,17 +64,20 @@ def set_unsupported_attribute(*args):
 # done for each invocation of __setitem__. Now this
 # mapping is built once during initialization of the
 # module.
-_method_dict = {}
+MethodList = list[Callable[[ifcopenshell_wrapper.entity_instance, int, Any], Union[None, NoReturn]]]
+"""List of setter methods for class attributes."""
+_method_dict: dict[str, MethodList] = {}
+"""Mapping of entity classes (e.g. 'IFC4.IfcWall') to MethodLists."""
 
 
 def register_schema_attributes(schema: ifcopenshell_wrapper.schema_definition) -> None:
     for decl in schema.declarations():
-        decl: ifcopenshell_wrapper.declaration
         if hasattr(decl, "argument_types"):
             fq_name = ".".join((schema.name(), decl.name()))
 
             # get type strings as reported by IfcOpenShell C++
             type_strs = decl.argument_types()
+            type_strs = cast(Sequence[str], type_strs)
 
             # convert case for setter function
             type_strs = [x.title().replace(" ", "") for x in type_strs]

src/ifcopenshell-python/ifcopenshell/ifcopenshell_wrapper.pyi

@@ -16,6 +16,7 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
+import ifcopenshell
 from typing import Any, Union, Literal
 
 # `std::vector<xxx>` usually translated to `tuple[xxx, ...]`.
@@ -775,6 +776,9 @@ class entity(declaration):
     def supertype(self) -> Union[entity, None]: ...
 
 class entity_instance:
+    file: ifcopenshell.file
+    """Reference to IFC file to prevent it's garbage collection, if entity is still used."""
+
     file_: Any
     id_: Any
     def data(self, *args): ...

src/ifcopenshell-python/ifcopenshell/util/cost.py

@@ -282,9 +282,10 @@ def get_cost_values(cost_item: ifcopenshell.entity_instance) -> list[dict[str, s
 
 
 def get_cost_schedule_types(file: ifcopenshell.file) -> list[dict[str, str]]:
-    schema: ifcopenshell_wrapper.schema_definition = ifcopenshell_wrapper.schema_by_name(file.schema_identifier)
+    schema = ifcopenshell_wrapper.schema_by_name(file.schema_identifier)
     results = []
-    declaration = schema.declaration_by_name("IfcCostSchedule")
+    declaration = schema.declaration_by_name("IfcCostSchedule").as_entity()
+    assert declaration
     version = file.schema_identifier
     for attribute in declaration.attributes():
         if attribute.name() == "PredefinedType":

src/ifcopenshell-python/ifcopenshell/util/schema.py

@@ -136,8 +136,8 @@ def get_subtypes(
         [<entity IfcFlowSegment>, <entity IfcCableCarrierSegment>, ..., <entity IfcPipeSegment>]
     """
 
-    def get_classes(decl):
-        results = []
+    def get_classes(decl: ifcopenshell_wrapper.entity) -> list[ifcopenshell_wrapper.entity]:
+        results: list[ifcopenshell_wrapper.entity] = []
         if not decl.is_abstract():
             results.append(decl)
         for subtype in decl.subtypes():
@@ -172,7 +172,7 @@ def reassign_class(
     if not ifc_file:
         ifc_file = element.file
 
-    schema: ifcopenshell_wrapper.schema_definition = ifcopenshell_wrapper.schema_by_name(ifc_file.schema_identifier)
+    schema = ifcopenshell_wrapper.schema_by_name(ifc_file.schema_identifier)
     try:
         declaration = schema.declaration_by_name(new_class)
     except RuntimeError:

src/ifcopenshell-python/ifcopenshell/util/unit.py

@@ -815,12 +815,13 @@ def iter_element_and_attributes_per_type(ifc_file: ifcopenshell.file, attr_type_
     None,
     None,
 ]:
-    schema: ifcopenshell_wrapper.schema_definition = ifcopenshell_wrapper.schema_by_name(ifc_file.schema_identifier)
+    schema = ifcopenshell_wrapper.schema_by_name(ifc_file.schema_identifier)
 
     for element in ifc_file:
-        entity = schema.declaration_by_name(element.is_a())
+        entity = schema.declaration_by_name(element.is_a()).as_entity()
+        assert entity
         attrs = entity.all_attributes()
-        attrs_derived: tuple[bool, ...] = entity.derived()
+        attrs_derived = entity.derived()
         for attr, val, is_derived in zip(attrs, list(element), attrs_derived):
             if is_derived:
                 continue