fix mypy errors

Signed-off-by: Anatoly Myachev <[email protected]>

modin/core/dataframe/pandas/dataframe/dataframe.py

@@ -57,6 +57,9 @@
         ProtocolDataframe,
     )
     from pandas._typing import npt
+    from modin.core.dataframe.pandas.partitioning.partition_manager import (
+        PandasDataframePartitionManager,
+    )
 
 from modin.logging import ClassLogger
 from modin.logging.config import LogLevel
@@ -95,7 +98,7 @@ class PandasDataframe(
         The data types for the dataframe columns.
     """
 
-    _partition_mgr_cls = None
+    _partition_mgr_cls: PandasDataframePartitionManager
     _query_compiler_cls = PandasQueryCompiler
     # These properties flag whether or not we are deferring the metadata synchronization
     _deferred_index = False
@@ -874,7 +877,7 @@ def synchronize_labels(self, axis=None):
         else:
             self._deferred_column = True
 
-    def _propagate_index_objs(self, axis=None):
+    def _propagate_index_objs(self, axis=None) -> None:
         """
         Synchronize labels by applying the index object for specific `axis` to the `self._partitions` lazily.
 

modin/distributed/dataframe/pandas/partitions.py

@@ -90,7 +90,7 @@ def unwrap_partitions(
             f"Only API Layer objects may be passed in here, got {type(api_layer_object)} instead."
         )
 
-    modin_frame = api_layer_object._query_compiler._modin_frame  # type: ignore[attr-defined]
+    modin_frame = api_layer_object._query_compiler._modin_frame
     modin_frame._propagate_index_objs(None)
     if axis is None:
 
@@ -122,7 +122,7 @@ def get_block(partition: PartitionUnionType) -> np.ndarray:
                 ]
 
         actual_engine = type(
-            api_layer_object._query_compiler._modin_frame._partitions[0][0]  # type: ignore[attr-defined]
+            api_layer_object._query_compiler._modin_frame._partitions[0][0]
         ).__name__
         if actual_engine in (
             "PandasOnRayDataframePartition",