fix: annotate umap weighted edges for mypy

Author: lmeyerov

CHANGELOG.md

@@ -8,6 +8,9 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ## [Development]
 <!-- Do Not Erase This Section - Used for tracking unreleased changes -->
 
+### Fixed
+- **Mypy**: Declare UMAP mixin weighted-edge DataFrame attributes for type checking.
+
 ## [0.50.5 - 2026-01-25]
 
 ### Fixed

graphistry/umap_utils.py

@@ -26,14 +26,18 @@
 
 logger = setup_logger(__name__)
 
+DataFrameLike = Union[pd.DataFrame, Any]
+
 if TYPE_CHECKING:
-    MIXIN_BASE = FeatureMixin
+    class _UMAPMixinBase(FeatureMixin):
+        _weighted_edges_df: Optional[DataFrameLike]
+        _weighted_edges_df_from_nodes: Optional[DataFrameLike]
+        _weighted_edges_df_from_edges: Optional[DataFrameLike]
+
+    MIXIN_BASE = _UMAPMixinBase
 else:
     MIXIN_BASE = object
 
-
-DataFrameLike = Union[pd.DataFrame, Any]
-
 # Error message for empty feature matrix
 _EMPTY_FEATURES_ERROR_MSG = (
     "UMAP requires at least one numeric feature column, but received empty feature matrix. "