REFACTOR-#7271: Remove instance_type attribute of axis partitions (#…

…7268)

Signed-off-by: Anatoly Myachev <anatoly.myachev@intel.com>

modin/core/dataframe/base/partitioning/axis_partition.py

@@ -14,7 +14,7 @@
 """Base class of an axis partition for a Modin Dataframe."""
 
 from abc import ABC, abstractmethod
-from typing import Any, Callable, Iterable, Optional, Tuple, Union
+from typing import Any, Callable, Iterable, Optional, Tuple, Type, Union
 
 from modin.logging import ClassLogger
 from modin.logging.config import LogLevel
@@ -95,8 +95,7 @@ def apply(
         pass
 
     # Child classes must have these in order to correctly subclass.
-    instance_type = None
-    partition_type = None
+    partition_type: Type
     _PARTITIONS_METADATA_LEN = 0
 
     def _wrap_partitions(
@@ -119,7 +118,6 @@ def _wrap_partitions(
             List of wrapped remote partition objects.
         """
         assert self.partition_type is not None
-        assert self.instance_type is not None  # type: ignore
 
         if extract_metadata is None:
             # If `_PARTITIONS_METADATA_LEN == 0` then the execution doesn't support metadata

modin/core/execution/dask/implementations/pandas_on_dask/partitioning/virtual_partition.py

@@ -14,7 +14,6 @@
 """Module houses classes responsible for storing a virtual partition and applying a function to it."""
 
 import pandas
-from distributed import Future
 from distributed.utils import get_ip
 
 from modin.core.dataframe.pandas.partitioning.axis_partition import (
@@ -51,7 +50,6 @@ class PandasOnDaskDataframeVirtualPartition(PandasDataframeAxisPartition):
     axis = None
     _PARTITIONS_METADATA_LEN = 3  # (length, width, ip)
     partition_type = PandasOnDaskDataframePartition
-    instance_type = Future
 
     @property
     def list_of_ips(self):

modin/core/execution/python/implementations/pandas_on_python/partitioning/virtual_partition.py

@@ -13,8 +13,6 @@
 
 """The module defines interface for a virtual partition with pandas storage format and python engine."""
 
-import pandas
-
 from modin.core.dataframe.pandas.partitioning.axis_partition import (
     PandasDataframeAxisPartition,
 )
@@ -48,7 +46,6 @@ class PandasOnPythonDataframeAxisPartition(PandasDataframeAxisPartition):
     """
 
     partition_type = PandasOnPythonDataframePartition
-    instance_type = pandas.DataFrame
 
 
 @_inherit_docstrings(PandasOnPythonDataframeAxisPartition.__init__)

modin/core/execution/ray/implementations/cudf_on_ray/partitioning/axis_partition.py

@@ -13,8 +13,6 @@
 
 """Module houses classes of axis partitions implemented using Ray and cuDF."""
 
-import cudf
-
 from modin.core.execution.ray.common import RayWrapper
 
 from .partition import cuDFOnRayDataframePartition
@@ -34,7 +32,6 @@ def __init__(self, partitions):
         self.partitions = [obj for obj in partitions]
 
     partition_type = cuDFOnRayDataframePartition
-    instance_type = cudf.DataFrame
 
 
 class cuDFOnRayDataframeColumnPartition(cuDFOnRayDataframeAxisPartition):

modin/core/execution/ray/implementations/pandas_on_ray/partitioning/virtual_partition.py

@@ -51,7 +51,6 @@ class PandasOnRayDataframeVirtualPartition(PandasDataframeAxisPartition):
 
     _PARTITIONS_METADATA_LEN = 3  # (length, width, ip)
     partition_type = PandasOnRayDataframePartition
-    instance_type = ray.ObjectRef
     axis = None
 
     # these variables are intentionally initialized at runtime (see #6023)

modin/core/execution/unidist/implementations/pandas_on_unidist/partitioning/virtual_partition.py

@@ -52,7 +52,6 @@ class PandasOnUnidistDataframeVirtualPartition(PandasDataframeAxisPartition):
 
     _PARTITIONS_METADATA_LEN = 3  # (length, width, ip)
     partition_type = PandasOnUnidistDataframePartition
-    instance_type = unidist.core.base.object_ref.ObjectRef
     axis = None
 
     # these variables are intentionally initialized at runtime (see #6023)