TYP: Upgrade mypy to 0.981

doc/source/whatsnew/v1.6.0.rst

@@ -96,7 +96,7 @@ If installed, we now require:
 +-----------------+-----------------+----------+---------+
 | Package         | Minimum Version | Required | Changed |
 +=================+=================+==========+=========+
-|                 |                 |    X     |    X    |
+| mypy (dev)      | 0.981           |          |    X    |
 +-----------------+-----------------+----------+---------+
 
 For `optional libraries <https://pandas.pydata.org/docs/getting_started/install.html>`_ the general recommendation is to use the latest version.

environment.yml

@@ -89,7 +89,7 @@ dependencies:
   - flake8=5.0.4
   - flake8-bugbear=22.7.1 # used by flake8, find likely bugs
   - isort>=5.2.1  # check that imports are in the right order
-  - mypy=0.971
+  - mypy=0.981
   - pre-commit>=2.15.0
   - pycodestyle  # used by flake8
   - pyupgrade

pandas/core/apply.py

@@ -507,8 +507,12 @@ def agg_dict_like(self) -> DataFrame | Series:
                 keys_to_use = ktu
 
             axis = 0 if isinstance(obj, ABCSeries) else 1
+            # error: Key expression in dictionary comprehension has incompatible type
+            # "Hashable"; expected type "NDFrame"  [misc]
             result = concat(
-                {k: results[k] for k in keys_to_use}, axis=axis, keys=keys_to_use
+                {k: results[k] for k in keys_to_use},  # type: ignore[misc]
+                axis=axis,
+                keys=keys_to_use,
             )
         elif any(is_ndframe):
             # There is a mix of NDFrames and scalars

pandas/core/arrays/interval.py

@@ -1400,9 +1400,7 @@ def set_closed(self: IntervalArrayT, closed: IntervalClosedType) -> IntervalArra
         either monotonic increasing or monotonic decreasing.
         """
 
-    # https://github.com/python/mypy/issues/1362
-    # Mypy does not support decorated properties
-    @property  # type: ignore[misc]
+    @property
     @Appender(
         _interval_shared_docs["is_non_overlapping_monotonic"] % _shared_docs_kwargs
     )

pandas/core/computation/scope.py

@@ -318,13 +318,5 @@ def full_scope(self) -> DeepChainMap:
         vars : DeepChainMap
             All variables in this scope.
         """
-        # error: Unsupported operand types for + ("List[Dict[Any, Any]]" and
-        # "List[Mapping[Any, Any]]")
-        # error: Unsupported operand types for + ("List[Dict[Any, Any]]" and
-        # "List[Mapping[str, Any]]")
-        maps = (
-            [self.temps]
-            + self.resolvers.maps  # type: ignore[operator]
-            + self.scope.maps  # type: ignore[operator]
-        )
+        maps = [self.temps] + self.resolvers.maps + self.scope.maps
         return DeepChainMap(*maps)

pandas/core/generic.py

@@ -4520,6 +4520,7 @@ def drop(
 
         if inplace:
             self._update_inplace(obj)
+            return None
         else:
             return obj
 
@@ -6953,10 +6954,7 @@ def fillna(
 
                     result = self.T.fillna(value=value, limit=limit).T
 
-                    # error: Incompatible types in assignment (expression has type
-                    # "NDFrameT", variable has type "Union[ArrayManager,
-                    # SingleArrayManager, BlockManager, SingleBlockManager]")
-                    new_data = result  # type: ignore[assignment]
+                    new_data = result
                 else:
 
                     new_data = self._mgr.fillna(

pandas/core/groupby/generic.py

@@ -687,17 +687,8 @@ def value_counts(
 
         # multi-index components
         codes = self.grouper.reconstructed_codes
-        # error: Incompatible types in assignment (expression has type
-        # "List[ndarray[Any, dtype[_SCT]]]",
-        # variable has type "List[ndarray[Any, dtype[signedinteger[Any]]]]")
-        codes = [  # type: ignore[assignment]
-            rep(level_codes) for level_codes in codes
-        ] + [llab(lab, inc)]
-        # error: List item 0 has incompatible type "Union[ndarray[Any, Any], Index]";
-        # expected "Index"
-        levels = [ping.group_index for ping in self.grouper.groupings] + [
-            lev  # type: ignore[list-item]
-        ]
+        codes = [rep(level_codes) for level_codes in codes] + [llab(lab, inc)]
+        levels = [ping.group_index for ping in self.grouper.groupings] + [lev]
 
         if dropna:
             mask = codes[-1] != -1
@@ -905,8 +896,7 @@ def tshift(self, periods: int = 1, freq=None) -> Series:
         result = self._op_via_apply("tshift", periods=periods, freq=freq)
         return result
 
-    # Decorated property not supported - https://github.com/python/mypy/issues/1362
-    @property  # type: ignore[misc]
+    @property
     @doc(Series.plot.__doc__)
     def plot(self):
         result = GroupByPlot(self)
@@ -965,15 +955,13 @@ def cov(
         )
         return result
 
-    # Decorated property not supported - https://github.com/python/mypy/issues/1362
-    @property  # type: ignore[misc]
+    @property
     @doc(Series.is_monotonic_increasing.__doc__)
     def is_monotonic_increasing(self) -> Series:
         result = self._op_via_apply("is_monotonic_increasing")
         return result
 
-    # Decorated property not supported - https://github.com/python/mypy/issues/1362
-    @property  # type: ignore[misc]
+    @property
     @doc(Series.is_monotonic_decreasing.__doc__)
     def is_monotonic_decreasing(self) -> Series:
         result = self._op_via_apply("is_monotonic_decreasing")
@@ -1012,8 +1000,7 @@ def hist(
         )
         return result
 
-    # Decorated property not supported - https://github.com/python/mypy/issues/1362
-    @property  # type: ignore[misc]
+    @property
     @doc(Series.dtype.__doc__)
     def dtype(self) -> Series:
         result = self._op_via_apply("dtype")
@@ -2336,7 +2323,7 @@ def tshift(self, periods: int = 1, freq=None, axis: Axis = 0) -> DataFrame:
         result = self._op_via_apply("tshift", periods=periods, freq=freq, axis=axis)
         return result
 
-    @property  # type: ignore[misc]
+    @property
     @doc(DataFrame.plot.__doc__)
     def plot(self) -> GroupByPlot:
         result = GroupByPlot(self)
@@ -2407,8 +2394,7 @@ def hist(
         )
         return result
 
-    # Decorated property not supported - https://github.com/python/mypy/issues/1362
-    @property  # type: ignore[misc]
+    @property
     @doc(DataFrame.dtypes.__doc__)
     def dtypes(self) -> Series:
         result = self._op_via_apply("dtypes")

pandas/core/indexes/base.py

@@ -5171,9 +5171,7 @@ def values(self) -> ArrayLike:
         """
         return self._data
 
-    # error: Decorated property not supported
-    # https://github.com/python/mypy/issues/1362
-    @cache_readonly  # type: ignore[misc]
+    @cache_readonly
     @doc(IndexOpsMixin.array)
     def array(self) -> ExtensionArray:
         array = self._data

pandas/core/indexes/frozen.py

@@ -65,7 +65,10 @@ def difference(self, other) -> FrozenList:
         return type(self)(temp)
 
     # TODO: Consider deprecating these in favor of `union` (xref gh-15506)
-    __add__ = __iadd__ = union
+    # error: Incompatible types in assignment (expression has type
+    # "Callable[[FrozenList, Any], FrozenList]", base class "list" defined the
+    # type as overloaded function)
+    __add__ = __iadd__ = union  # type: ignore[assignment]
 
     def __getitem__(self, n):
         if isinstance(n, slice):

pandas/core/indexes/numeric.py

@@ -213,8 +213,7 @@ def _ensure_dtype(cls, dtype: Dtype | None) -> np.dtype | None:
     # ----------------------------------------------------------------
     # Indexing Methods
 
-    # error: Decorated property not supported
-    @cache_readonly  # type: ignore[misc]
+    @cache_readonly
     @doc(Index._should_fallback_to_positional)
     def _should_fallback_to_positional(self) -> bool:
         return False

pandas/core/indexes/period.py

@@ -191,23 +191,17 @@ def to_timestamp(self, freq=None, how: str = "start") -> DatetimeIndex:
         arr = self._data.to_timestamp(freq, how)
         return DatetimeIndex._simple_new(arr, name=self.name)
 
-    # https://github.com/python/mypy/issues/1362
-    # error: Decorated property not supported
-    @property  # type: ignore[misc]
+    @property
     @doc(PeriodArray.hour.fget)
     def hour(self) -> Int64Index:
         return Int64Index(self._data.hour, name=self.name)
 
-    # https://github.com/python/mypy/issues/1362
-    # error: Decorated property not supported
-    @property  # type: ignore[misc]
+    @property
     @doc(PeriodArray.minute.fget)
     def minute(self) -> Int64Index:
         return Int64Index(self._data.minute, name=self.name)
 
-    # https://github.com/python/mypy/issues/1362
-    # error: Decorated property not supported
-    @property  # type: ignore[misc]
+    @property
     @doc(PeriodArray.second.fget)
     def second(self) -> Int64Index:
         return Int64Index(self._data.second, name=self.name)

pandas/core/reshape/merge.py

@@ -1725,7 +1725,8 @@ def _convert_to_multiindex(index: Index) -> MultiIndex:
         else:
             restore_codes = algos.take_nd(codes, indexer, fill_value=-1)
 
-        join_levels = join_levels + [restore_levels]
+        # error: Cannot determine type of "__add__"
+        join_levels = join_levels + [restore_levels]  # type: ignore[has-type]
         join_codes = join_codes + [restore_codes]
         join_names = join_names + [dropped_level_name]
 

pandas/core/reshape/reshape.py

@@ -316,7 +316,10 @@ def get_new_columns(self, value_columns: Index | None):
         new_levels: FrozenList | list[Index]
 
         if isinstance(value_columns, MultiIndex):
-            new_levels = value_columns.levels + (self.removed_level_full,)
+            # error: Cannot determine type of "__add__"  [has-type]
+            new_levels = value_columns.levels + (  # type: ignore[has-type]
+                self.removed_level_full,
+            )
             new_names = value_columns.names + (self.removed_name,)
 
             new_codes = [lab.take(propagator) for lab in value_columns.codes]

pandas/io/common.py

@@ -574,9 +574,7 @@ def infer_compression(
     if compression in _supported_compressions:
         return compression
 
-    # https://github.com/python/mypy/issues/5492
-    # Unsupported operand types for + ("List[Optional[str]]" and "List[str]")
-    valid = ["infer", None] + sorted(_supported_compressions)  # type: ignore[operator]
+    valid = ["infer", None] + sorted(_supported_compressions)
     msg = (
         f"Unrecognized compression type: {compression}\n"
         f"Valid compression types are {valid}"

pandas/io/pytables.py

@@ -3481,9 +3481,7 @@ def queryables(self) -> dict[str, Any]:
             (v.cname, v) for v in self.values_axes if v.name in set(self.data_columns)
         ]
 
-        # error: Unsupported operand types for + ("List[Tuple[str, IndexCol]]" and
-        # "List[Tuple[str, None]]")
-        return dict(d1 + d2 + d3)  # type: ignore[operator]
+        return dict(d1 + d2 + d3)
 
     def index_cols(self):
         """return a list of my index cols"""

pandas/tests/frame/indexing/test_setitem.py

@@ -260,9 +260,7 @@ def test_setitem_extension_types(self, obj, dtype):
             # property would require instantiation
             if not isinstance(dtype.name, property)
         ]
-        # mypy doesn't allow adding lists of different types
-        # https://github.com/python/mypy/issues/5492
-        + ["datetime64[ns, UTC]", "period[D]"],  # type: ignore[list-item]
+        + ["datetime64[ns, UTC]", "period[D]"],
     )
     def test_setitem_with_ea_name(self, ea_name):
         # GH 38386

pandas/tests/resample/test_datetime_index.py

@@ -1300,7 +1300,7 @@ def test_resample_consistency():
 dates2: List[DatetimeNaTType] = (
     dates1[:2] + [pd.NaT] + dates1[2:4] + [pd.NaT] + dates1[4:]
 )
-dates3 = [pd.NaT] + dates1 + [pd.NaT]  # type: ignore[operator]
+dates3 = [pd.NaT] + dates1 + [pd.NaT]
 
 
 @pytest.mark.parametrize("dates", [dates1, dates2, dates3])

pandas/tests/tools/test_to_datetime.py

@@ -1086,11 +1086,11 @@ def test_convert_object_to_datetime_with_cache(
         ("input", "expected"),
         (
             (
-                Series([NaT] * 20 + [None] * 20, dtype="object"),  # type: ignore[list-item] # noqa: E501
+                Series([NaT] * 20 + [None] * 20, dtype="object"),
                 Series([NaT] * 40, dtype="datetime64[ns]"),
             ),
             (
-                Series([NaT] * 60 + [None] * 60, dtype="object"),  # type: ignore[list-item] # noqa: E501
+                Series([NaT] * 60 + [None] * 60, dtype="object"),
                 Series([NaT] * 120, dtype="datetime64[ns]"),
             ),
             (Series([None] * 20), Series([NaT] * 20, dtype="datetime64[ns]")),

requirements-dev.txt

@@ -68,7 +68,7 @@ cpplint
 flake8==5.0.4
 flake8-bugbear==22.7.1
 isort>=5.2.1
-mypy==0.971
+mypy==0.981
 pre-commit>=2.15.0
 pycodestyle
 pyupgrade