TYP: fix some of the __hash__ methods (#47654)

Author: twoertwein

pandas/core/arrays/arrow/_arrow_utils.py

@@ -92,7 +92,7 @@ def __eq__(self, other):
  else:
  return NotImplemented
 
- def __hash__(self):
+ def __hash__(self) -> int:
  return hash((str(self), self.freq))
 
  def to_pandas_dtype(self):
@@ -158,7 +158,7 @@ def __eq__(self, other):
  else:
  return NotImplemented
 
- def __hash__(self):
+ def __hash__(self) -> int:
  return hash((str(self), str(self.subtype), self.inclusive))
 
  def to_pandas_dtype(self):

pandas/core/arrays/base.py

@@ -14,6 +14,7 @@
  TYPE_CHECKING,
  Any,
  Callable,
+ ClassVar,
  Iterator,
  Literal,
  Sequence,
@@ -1442,7 +1443,7 @@ def _reduce(self, name: str, *, skipna: bool = True, **kwargs):
  # https://github.com/python/typeshed/issues/2148#issuecomment-520783318
  # Incompatible types in assignment (expression has type "None", base class
  # "object" defined the type as "Callable[[object], int]")
- __hash__: None # type: ignore[assignment]
+ __hash__: ClassVar[None] # type: ignore[assignment]
 
  # ------------------------------------------------------------------------
  # Non-Optimized Default Methods; in the case of the private methods here,

pandas/core/arrays/sparse/dtype.py

@@ -99,7 +99,7 @@ def __init__(self, dtype: Dtype = np.float64, fill_value: Any = None) -> None:
  self._fill_value = fill_value
  self._check_fill_value()
 
- def __hash__(self):
+ def __hash__(self) -> int:
  # Python3 doesn't inherit __hash__ when a base class overrides
  # __eq__, so we explicitly do it here.
  return super().__hash__()

pandas/core/generic.py

@@ -13,6 +13,7 @@
  TYPE_CHECKING,
  Any,
  Callable,
+ ClassVar,
  Hashable,
  Literal,
  Mapping,
@@ -1882,7 +1883,7 @@ def _drop_labels_or_levels(self, keys, axis: int = 0):
  # https://github.com/python/typeshed/issues/2148#issuecomment-520783318
  # Incompatible types in assignment (expression has type "None", base class
  # "object" defined the type as "Callable[[object], int]")
- __hash__: None # type: ignore[assignment]
+ __hash__: ClassVar[None] # type: ignore[assignment]
 
  def __iter__(self):
  """

pandas/core/indexes/base.py

@@ -8,6 +8,7 @@
  TYPE_CHECKING,
  Any,
  Callable,
+ ClassVar,
  Hashable,
  Iterable,
  Literal,
@@ -5296,7 +5297,7 @@ def __contains__(self, key: Any) -> bool:
  # https://github.com/python/typeshed/issues/2148#issuecomment-520783318
  # Incompatible types in assignment (expression has type "None", base class
  # "object" defined the type as "Callable[[object], int]")
- __hash__: None # type: ignore[assignment]
+ __hash__: ClassVar[None] # type: ignore[assignment]
 
  @final
  def __setitem__(self, key, value):

pandas/core/indexes/frozen.py

@@ -89,7 +89,8 @@ def __mul__(self, other):
  def __reduce__(self):
  return type(self), (list(self),)
 
- def __hash__(self):
+ # error: Signature of "__hash__" incompatible with supertype "list"
+ def __hash__(self) -> int: # type: ignore[override]
  return hash(tuple(self))
 
  def _disabled(self, *args, **kwargs):