TYP: move imports inside TYPE_CHECKING (#47968)

Author: twoertwein

pandas/core/arrays/period.py

@@ -77,7 +77,6 @@
 
 import pandas.core.algorithms as algos
 from pandas.core.arrays import datetimelike as dtl
-from pandas.core.arrays.base import ExtensionArray
 import pandas.core.common as com
 
 if TYPE_CHECKING:
@@ -91,6 +90,8 @@
         DatetimeArray,
         TimedeltaArray,
     )
+    from pandas.core.arrays.base import ExtensionArray
+
 
 BaseOffsetT = TypeVar("BaseOffsetT", bound=BaseOffset)
 

pandas/core/computation/engines.py

@@ -4,21 +4,24 @@
 from __future__ import annotations
 
 import abc
+from typing import TYPE_CHECKING
 
 from pandas.errors import NumExprClobberingError
 
 from pandas.core.computation.align import (
     align_terms,
     reconstruct_object,
 )
-from pandas.core.computation.expr import Expr
 from pandas.core.computation.ops import (
     MATHOPS,
     REDUCTIONS,
 )
 
 import pandas.io.formats.printing as printing
 
+if TYPE_CHECKING:
+    from pandas.core.computation.expr import Expr
+
 _ne_builtins = frozenset(MATHOPS + REDUCTIONS)
 
 

pandas/core/computation/eval.py

@@ -4,6 +4,7 @@
 from __future__ import annotations
 
 import tokenize
+from typing import TYPE_CHECKING
 import warnings
 
 from pandas._libs.lib import no_default
@@ -15,12 +16,14 @@
     PARSERS,
     Expr,
 )
-from pandas.core.computation.ops import BinOp
 from pandas.core.computation.parsing import tokenize_string
 from pandas.core.computation.scope import ensure_scope
 
 from pandas.io.formats.printing import pprint_thing
 
+if TYPE_CHECKING:
+    from pandas.core.computation.ops import BinOp
+
 
 def _check_engine(engine: str | None) -> str:
     """

pandas/core/computation/pytables.py

@@ -3,7 +3,10 @@
 
 import ast
 from functools import partial
-from typing import Any
+from typing import (
+    TYPE_CHECKING,
+    Any,
+)
 
 import numpy as np
 
@@ -12,7 +15,6 @@
     Timestamp,
 )
 from pandas._typing import npt
-from pandas.compat.chainmap import DeepChainMap
 from pandas.errors import UndefinedVariableError
 
 from pandas.core.dtypes.common import is_list_like
@@ -34,6 +36,9 @@
     pprint_thing_encoded,
 )
 
+if TYPE_CHECKING:
+    from pandas.compat.chainmap import DeepChainMap
+
 
 class PyTablesScope(_scope.Scope):
     __slots__ = ("queryables",)

pandas/core/groupby/categorical.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from typing import TYPE_CHECKING
+
 import numpy as np
 
 from pandas.core.algorithms import unique1d
@@ -8,7 +10,9 @@
     CategoricalDtype,
     recode_for_categories,
 )
-from pandas.core.indexes.api import CategoricalIndex
+
+if TYPE_CHECKING:
+    from pandas.core.indexes.api import CategoricalIndex
 
 
 def recode_for_groupby(

pandas/core/groupby/generic.py

@@ -11,6 +11,7 @@
 from functools import partial
 from textwrap import dedent
 from typing import (
+    TYPE_CHECKING,
     Any,
     Callable,
     Hashable,
@@ -72,7 +73,6 @@
 import pandas.core.common as com
 from pandas.core.construction import create_series_with_explicit_dtype
 from pandas.core.frame import DataFrame
-from pandas.core.generic import NDFrame
 from pandas.core.groupby import base
 from pandas.core.groupby.groupby import (
     GroupBy,
@@ -93,6 +93,9 @@
 
 from pandas.plotting import boxplot_frame_groupby
 
+if TYPE_CHECKING:
+    from pandas.core.generic import NDFrame
+
 # TODO(typing) the return value on this callable should be any *scalar*.
 AggScalar = Union[str, Callable[..., Any]]
 # TODO: validate types on ScalarResult and move to _typing

pandas/core/groupby/ops.py

@@ -10,6 +10,7 @@
 import collections
 import functools
 from typing import (
+    TYPE_CHECKING,
     Callable,
     Generic,
     Hashable,
@@ -77,7 +78,6 @@
 )
 from pandas.core.arrays.string_ import StringDtype
 from pandas.core.frame import DataFrame
-from pandas.core.generic import NDFrame
 from pandas.core.groupby import grouper
 from pandas.core.indexes.api import (
     CategoricalIndex,
@@ -95,6 +95,9 @@
     get_indexer_dict,
 )
 
+if TYPE_CHECKING:
+    from pandas.core.generic import NDFrame
+
 
 class WrappedCythonOp:
     """

pandas/core/indexes/extension.py

@@ -4,6 +4,7 @@
 from __future__ import annotations
 
 from typing import (
+    TYPE_CHECKING,
     Callable,
     TypeVar,
 )
@@ -21,10 +22,12 @@
 
 from pandas.core.dtypes.generic import ABCDataFrame
 
-from pandas.core.arrays import IntervalArray
-from pandas.core.arrays._mixins import NDArrayBackedExtensionArray
 from pandas.core.indexes.base import Index
 
+if TYPE_CHECKING:
+    from pandas.core.arrays import IntervalArray
+    from pandas.core.arrays._mixins import NDArrayBackedExtensionArray
+
 _T = TypeVar("_T", bound="NDArrayBackedExtensionIndex")
 _ExtensionIndexT = TypeVar("_ExtensionIndexT", bound="ExtensionIndex")
 

pandas/core/interchange/dataframe.py

@@ -3,11 +3,11 @@
 from collections import abc
 from typing import TYPE_CHECKING
 
-import pandas as pd
 from pandas.core.interchange.column import PandasColumn
 from pandas.core.interchange.dataframe_protocol import DataFrame as DataFrameXchg
 
 if TYPE_CHECKING:
+    import pandas as pd
     from pandas import Index
 
 

pandas/core/internals/blocks.py

@@ -98,7 +98,6 @@
     PeriodArray,
     TimedeltaArray,
 )
-from pandas.core.arrays._mixins import NDArrayBackedExtensionArray
 from pandas.core.arrays.sparse import SparseDtype
 from pandas.core.base import PandasObject
 import pandas.core.common as com
@@ -115,6 +114,7 @@
         Float64Index,
         Index,
     )
+    from pandas.core.arrays._mixins import NDArrayBackedExtensionArray
 
 # comparison is faster than is_object_dtype
 _dtype_obj = np.dtype("object")