TYP: investigate/fix ignored mypy errors
In #37556 `# type: ignore` were added to silence mypy errors to be fixed 'later'. If an ignore is needed due to a error with the type checker, a comment with a reference to the mypy issue on the github mypy issue tracker should be included.

Further investigation or PRs welcome removing these ignores or adding comments with links to mypy issues if applicable. PRs should include 'xref #37715'

PRs could address just one error, a small handful of related errors or a complete module.

`grep -Ern "type: ?ignore" pandas/` currently gives 207 matches

<details>

```
pandas/tests/internals/test_internals.py:1258:            assert df._mgr.blocks[0].values is arr  # type:ignore[union-attr]
pandas/tests/indexes/object/test_indexing.py:73:            (pd.IndexSlice["b":"y":-1], ""),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:74:            (pd.IndexSlice["b"::-1], "b"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:75:            (pd.IndexSlice[:"b":-1], "yxdcb"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:76:            (pd.IndexSlice[:"y":-1], "y"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:77:            (pd.IndexSlice["y"::-1], "yxdcb"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:78:            (pd.IndexSlice["y"::-4], "yb"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:80:            (pd.IndexSlice[:"a":-1], "yxdcb"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:81:            (pd.IndexSlice[:"a":-2], "ydb"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:82:            (pd.IndexSlice["z"::-1], "yxdcb"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:83:            (pd.IndexSlice["z"::-3], "yc"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:84:            (pd.IndexSlice["m"::-1], "dcb"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:85:            (pd.IndexSlice[:"m":-1], "yx"),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:86:            (pd.IndexSlice["a":"a":-1], ""),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:87:            (pd.IndexSlice["z":"z":-1], ""),  # type: ignore[misc]
pandas/tests/indexes/object/test_indexing.py:88:            (pd.IndexSlice["m":"m":-1], ""),  # type: ignore[misc]
pandas/tests/frame/indexing/test_setitem.py:229:        + ["datetime64[ns, UTC]", "period[D]"],  # type: ignore[list-item]
pandas/tests/io/xml/test_xml.py:683:            filename, names="Col1, Col2, Col3", parser=parser  # type: ignore[arg-type]
pandas/conftest.py:330:    params=[pd.Index, pd.Series], ids=["index", "series"]  # type: ignore[list-item]
pandas/_testing/_io.py:98:            args = []  # type: ignore[assignment]
pandas/_testing/_io.py:219:                errno = getattr(err.reason, "errno", None)  # type: ignore[attr-defined]
pandas/_testing/__init__.py:574:        idx = idx_func(nentries)  # type: ignore[operator]
pandas/util/_decorators.py:93:    return wrapper  # type: ignore[return-value]
pandas/util/_decorators.py:341:        func.__signature__ = sig  # type: ignore[attr-defined]
pandas/util/_decorators.py:380:                    docstring._docstring_components  # type: ignore[union-attr]
pandas/util/_decorators.py:396:        decorated._docstring_components = (  # type: ignore[attr-defined]
pandas/core/generic.py:755:            new_values, *new_axes  # type: ignore[arg-type]
pandas/core/generic.py:4344:        return self.rename(**mapper)  # type: ignore[return-value, arg-type]
pandas/core/generic.py:4408:        return self.rename(**mapper)  # type: ignore[return-value, arg-type]
pandas/core/generic.py:10600:        cls.any = any  # type: ignore[assignment]
pandas/core/generic.py:10620:        cls.all = all  # type: ignore[assignment]
pandas/core/generic.py:10625:            NDFrame.mad.__doc__,  # type: ignore[arg-type]
pandas/core/generic.py:10638:        cls.mad = mad  # type: ignore[assignment]
pandas/core/generic.py:10661:        cls.sem = sem  # type: ignore[assignment]
pandas/core/generic.py:10683:        cls.var = var  # type: ignore[assignment]
pandas/core/generic.py:10706:        cls.std = std  # type: ignore[assignment]
pandas/core/generic.py:10721:        cls.cummin = cummin  # type: ignore[assignment]
pandas/core/generic.py:10736:        cls.cummax = cummax  # type: ignore[assignment]
pandas/core/generic.py:10751:        cls.cumsum = cumsum  # type: ignore[assignment]
pandas/core/generic.py:10766:        cls.cumprod = cumprod  # type: ignore[assignment]
pandas/core/generic.py:10793:        cls.sum = sum  # type: ignore[assignment]
pandas/core/generic.py:10819:        cls.prod = prod  # type: ignore[assignment]
pandas/core/generic.py:10836:        cls.mean = mean  # type: ignore[assignment]
pandas/core/generic.py:10852:        cls.skew = skew  # type: ignore[assignment]
pandas/core/generic.py:10871:        cls.kurt = kurt  # type: ignore[assignment]
pandas/core/generic.py:10890:        cls.median = median  # type: ignore[assignment]
pandas/core/generic.py:10908:        cls.max = max  # type: ignore[assignment]
pandas/core/generic.py:10926:        cls.min = min  # type: ignore[assignment]
pandas/core/generic.py:11049:        return self._inplace_method(other, type(self).__add__)  # type: ignore[operator]
pandas/core/generic.py:11052:        return self._inplace_method(other, type(self).__sub__)  # type: ignore[operator]
pandas/core/generic.py:11055:        return self._inplace_method(other, type(self).__mul__)  # type: ignore[operator]
pandas/core/generic.py:11059:            other, type(self).__truediv__  # type: ignore[operator]
pandas/core/generic.py:11064:            other, type(self).__floordiv__  # type: ignore[operator]
pandas/core/generic.py:11068:        return self._inplace_method(other, type(self).__mod__)  # type: ignore[operator]
pandas/core/generic.py:11071:        return self._inplace_method(other, type(self).__pow__)  # type: ignore[operator]
pandas/core/generic.py:11074:        return self._inplace_method(other, type(self).__and__)  # type: ignore[operator]
pandas/core/generic.py:11077:        return self._inplace_method(other, type(self).__or__)  # type: ignore[operator]
pandas/core/generic.py:11080:        return self._inplace_method(other, type(self).__xor__)  # type: ignore[operator]
pandas/core/dtypes/generic.py:43:    @classmethod  # type: ignore[misc]
pandas/core/dtypes/common.py:160:        return arr.astype("int64", copy=copy, casting="safe")  # type: ignore[call-arg]
pandas/core/dtypes/common.py:165:        return arr.astype("uint64", copy=copy, casting="safe")  # type: ignore[call-arg]
pandas/core/dtypes/cast.py:588:            dtype, fill_value, type(fill_value)  # type: ignore[arg-type]
pandas/core/dtypes/dtypes.py:680:            unit, tz = unit.unit, unit.tz  # type: ignore[attr-defined]
pandas/core/arrays/datetimelike.py:539:            other = self._scalar_type(other)  # type: ignore[call-arg]
pandas/core/arrays/datetimelike.py:590:            fill_value = self._scalar_type(fill_value)  # type: ignore[call-arg]
pandas/core/arrays/datetimelike.py:598:                new_fill = self._scalar_type(fill_value)  # type: ignore[call-arg]
pandas/core/arrays/datetimelike.py:660:            value = self._scalar_type(value)  # type: ignore[call-arg]
pandas/core/arrays/datetimelike.py:953:        return self._resolution_obj.attrname  # type: ignore[union-attr]
pandas/core/arrays/datetimelike.py:1777:                uniques = uniques[::-1]  # type: ignore[assignment]
pandas/core/arrays/string_.py:213:        self._dtype = StringDtype()  # type: ignore[assignment]
pandas/core/arrays/period.py:326:    @property  # type: ignore[misc]
pandas/core/arrays/boolean.py:81:    def type(self) -> Type:  # type: ignore[override]
pandas/core/arrays/interval.py:1350:    @property  # type: ignore[misc]
pandas/core/arrays/interval.py:1572:                left = self._combined.view("complex128")  # type:ignore[attr-defined]
pandas/core/arrays/floating.py:81:            [t.numpy_dtype for t in dtypes], []  # type: ignore[union-attr]
pandas/core/internals/array_manager.py:151:    def axes(self) -> List[Index]:  # type: ignore[override]
pandas/core/internals/array_manager.py:457:            if hasattr(arr, "tz") and arr.tz is None:  # type: ignore[union-attr]
pandas/core/internals/array_manager.py:459:                arr = arr._data  # type: ignore[union-attr]
pandas/core/internals/array_manager.py:462:                arr = arr._data  # type: ignore[union-attr]
pandas/core/series.py:669:    @Appender(base.IndexOpsMixin.array.__doc__)  # type: ignore[misc]
pandas/core/series.py:1097:        self._mgr = self._mgr.setitem(  # type: ignore[assignment]
pandas/core/apply.py:563:                    new_func[k] = [v]  # type:ignore[list-item]
pandas/core/nanops.py:1751:            result = type(values)._simple_new(  # type: ignore[attr-defined]
pandas/core/groupby/categorical.py:108:        return ci.set_categories(c.categories)  # type: ignore[attr-defined]
pandas/core/groupby/categorical.py:113:    return ci.add_categories(new_cats)  # type: ignore[attr-defined]
pandas/core/groupby/base.py:60:            subset = self.obj  # type: ignore[attr-defined]
pandas/core/groupby/base.py:69:            groupby = self._groupby[key]  # type: ignore[attr-defined]
pandas/core/groupby/base.py:72:            groupby = self._groupby  # type: ignore[attr-defined]
pandas/core/groupby/base.py:78:            subset, groupby=groupby, parent=self, **kwargs  # type: ignore[call-arg]
pandas/core/groupby/grouper.py:306:        self.grouper, _, self.obj = get_grouper(  # type: ignore[type-var]
pandas/core/groupby/grouper.py:393:        return self.grouper.groups  # type: ignore[union-attr]
pandas/core/indexes/datetimelike.py:85:    @staticmethod  # type: ignore[misc]
pandas/core/indexes/datetimelike.py:131:        DatetimeLikeArrayMixin._hasnans.fget  # type: ignore[attr-defined]
pandas/core/indexes/period.py:193:    @property  # type:ignore[misc]
pandas/core/indexes/period.py:200:    @property  # type:ignore[misc]
pandas/core/indexes/period.py:207:    @property  # type:ignore[misc]
pandas/core/indexes/category.py:347:            ("ordered", self.ordered),  # type: ignore[attr-defined]
pandas/core/indexes/base.py:6174:        name = index_like.name  # type: ignore[union-attr, attr-defined]
pandas/core/indexes/frozen.py:107:    __setitem__ = __setslice__ = _disabled  # type: ignore[assignment]
pandas/core/indexes/frozen.py:108:    __delitem__ = __delslice__ = _disabled  # type: ignore[assignment]
pandas/core/indexes/frozen.py:109:    pop = append = extend = _disabled  # type: ignore[assignment]
pandas/core/indexes/frozen.py:110:    remove = sort = insert = _disabled  # type: ignore[assignment]
pandas/core/indexes/multi.py:1479:            self._names[lev] = name  # type: ignore[has-type]
pandas/core/common.py:497:        return values  # type: ignore[return-value]
pandas/core/reshape/merge.py:1028:        join_names = []  # type: ignore[var-annotated]
pandas/core/ops/array_ops.py:372:        res_values = filler(res_values)  # type: ignore[operator]
pandas/core/base.py:118:            mem = self.memory_usage(deep=True)  # type: ignore[attr-defined]
pandas/core/base.py:229:            self.obj, ABCSeries  # type: ignore[attr-defined]
pandas/core/base.py:232:            return self.obj  # type: ignore[attr-defined]
pandas/core/base.py:235:            return self.obj[self._selection]  # type: ignore[attr-defined]
pandas/core/base.py:245:            self.obj, ABCDataFrame  # type: ignore[attr-defined]
pandas/core/base.py:248:            return self.obj.reindex(  # type: ignore[attr-defined]
pandas/core/base.py:253:        if len(self.exclusions) > 0:  # type: ignore[attr-defined]
pandas/core/base.py:256:            return self.obj.drop(self.exclusions, axis=1)  # type: ignore[attr-defined]
pandas/core/base.py:259:            return self.obj  # type: ignore[attr-defined]
pandas/core/base.py:268:                self.obj.columns.intersection(key)  # type: ignore[attr-defined]
pandas/core/base.py:272:                    set(key).difference(self.obj.columns)  # type: ignore[attr-defined]
pandas/core/base.py:279:            if key not in self.obj.columns:  # type: ignore[attr-defined]
pandas/core/base.py:285:            if key not in self.obj:  # type: ignore[attr-defined]
pandas/core/base.py:611:            return self.array.to_numpy(  # type: ignore[call-arg]
pandas/core/base.py:924:                self = cast("Categorical", self)  # type: ignore[assignment]
pandas/core/base.py:927:                return self._values.map(mapper)  # type: ignore[union-attr]
pandas/core/base.py:945:            values = self.astype(object)._values  # type: ignore[attr-defined]
pandas/core/base.py:1183:            return self.array.memory_usage(deep=deep)  # type: ignore[attr-defined]
pandas/core/base.py:1318:        return self[~duplicated]  # type: ignore[index]
pandas/core/frame.py:1219:            itertuple = collections.namedtuple(  # type: ignore[misc]
pandas/core/frame.py:1236:    def dot(self, other: Series) -> Series:  # type: ignore[misc]
pandas/core/frame.py:2339:            from pandas.io.stata import (  # type: ignore[no-redef]
pandas/core/frame.py:2344:            from pandas.io.stata import (  # type: ignore[no-redef]
pandas/core/frame.py:2357:        writer = statawriter(  # type: ignore[call-arg]
pandas/core/frame.py:4082:                        unique_dtype.type, tuple(dtypes_set)  # type: ignore[arg-type]
pandas/core/frame.py:5100:                arrays.append(col)  # type:ignore[arg-type]
pandas/core/frame.py:5144:    def reset_index(  # type: ignore[misc]
pandas/core/frame.py:5783:    def sort_values(  # type: ignore[override]
pandas/core/frame.py:6385:                right._mgr, array_op  # type: ignore[arg-type]
pandas/core/resample.py:142:        self.grouper = None  # type: ignore[assignment]
pandas/core/resample.py:465:                self.loffset,  # type: ignore[has-type]
pandas/core/resample.py:474:            result.index = result.index + self.loffset  # type: ignore[has-type]
pandas/core/resample.py:911:        return self._downsample("std", ddof=ddof)  # type: ignore[call-arg]
pandas/core/resample.py:929:        return self._downsample("var", ddof=ddof)  # type: ignore[call-arg]
pandas/core/resample.py:989:        return self._downsample("quantile", q=q, **kwargs)  # type: ignore[call-arg]
pandas/core/resample.py:1042:        super().__init__(None)  # type: ignore[call-arg]
pandas/core/resample.py:1109:            and len(self.grouper.binlabels) > len(ax)  # type: ignore[attr-defined]
pandas/core/config_init.py:332:        ip = get_ipython()  # type: ignore[name-defined]
pandas/core/computation/pytables.py:88:    @property  # type: ignore[misc]
pandas/core/computation/ops.py:89:        supr_new = super(Term, klass).__new__  # type: ignore[misc]
pandas/core/computation/ops.py:610:        operands = [op(env) for op in self.operands]  # type: ignore[operator]
pandas/core/computation/expr.py:677:                f"Invalid function call {node.func.id}"  # type: ignore[attr-defined]
pandas/core/computation/expr.py:701:                        "keyword error in function call "  # type: ignore[attr-defined]
pandas/core/computation/expressions.py:241:            return _evaluate(op, op_str, a, b)  # type: ignore[misc]
pandas/core/computation/scope.py:136:            self.scope = self.scope.new_child(  # type: ignore[assignment]
pandas/core/computation/scope.py:142:                self.scope = self.scope.new_child(  # type: ignore[assignment]
pandas/core/computation/scope.py:151:            resolvers += tuple(local_dict.resolvers.maps)  # type: ignore[has-type]
pandas/core/computation/scope.py:239:                mapping[new_key] = new_value  # type: ignore[index]
pandas/core/computation/scope.py:260:                self.scope = self.scope.new_child(d)  # type: ignore[assignment]
pandas/core/computation/scope.py:333:            + self.resolvers.maps  # type: ignore[operator]
pandas/core/computation/scope.py:334:            + self.scope.maps  # type: ignore[operator]
pandas/compat/pickle_compat.py:74:    def __new__(cls) -> Series:  # type: ignore[misc]
pandas/compat/pickle_compat.py:92:    def __new__(cls) -> DataFrame:  # type: ignore[misc]
pandas/compat/pickle_compat.py:191:class Unpickler(pkl._Unpickler):  # type: ignore[name-defined]
pandas/plotting/_matplotlib/core.py:608:                    self.legend_handles = reversed(  # type: ignore[assignment]
pandas/plotting/_matplotlib/core.py:614:                    self.legend_labels = reversed(  # type: ignore[assignment]
pandas/plotting/_matplotlib/core.py:708:                args = (x, y)  # type: ignore[assignment]
pandas/plotting/_matplotlib/core.py:1161:            plotf = self._plot  # type: ignore[assignment]
pandas/plotting/_matplotlib/core.py:1611:                blabels = None  # type: ignore[assignment]
pandas/plotting/_matplotlib/timeseries.py:68:            series.index = series.index.asfreq(  # type: ignore[attr-defined]
pandas/plotting/_matplotlib/timeseries.py:248:            weekdays = np.unique(index.dayofweek)  # type: ignore[attr-defined]
pandas/plotting/_misc.py:534:        self.__init__()  # type: ignore[misc]
pandas/io/formats/excel.py:632:                gen2 = (  # type: ignore[assignment]
pandas/io/formats/excel.py:838:            writer = ExcelWriter(  # type: ignore[abstract]
pandas/io/formats/printing.py:507:    return head, tail  # type: ignore[return-value]
pandas/io/formats/printing.py:532:        attrs.append(("dtype", f"'{obj.dtype}'"))  # type: ignore[attr-defined]
pandas/io/formats/printing.py:535:        attrs.append(("name", default_pprint(obj.name)))  # type: ignore[attr-defined]
pandas/io/formats/printing.py:538:        obj.names  # type: ignore[attr-defined]
pandas/io/formats/printing.py:541:        attrs.append(("names", default_pprint(obj.names)))  # type: ignore[attr-defined]
pandas/io/formats/console.py:73:        return __IPYTHON__ or check_main()  # type: ignore[name-defined]
pandas/io/formats/console.py:88:        ip = get_ipython()  # type: ignore[name-defined]
pandas/io/formats/style.py:1847:        class MyStyler(cls):  # type:ignore[valid-type,misc]
pandas/io/formats/csvs.py:252:                handles.handle,  # type: ignore[arg-type]
pandas/io/formats/xml.py:278:                handles.handle.write(xml_doc)  # type: ignore[arg-type]
pandas/io/formats/format.py:1384:                    float_format(value=v)  # type: ignore[operator,call-arg]
pandas/io/pytables.py:2362:        itemsize = dtype.itemsize  # type: ignore[attr-defined]
pandas/io/pytables.py:3440:        return dict(d1 + d2 + d3)  # type: ignore[operator]
pandas/io/pytables.py:4025:            blocks = list(mgr.blocks)  # type: ignore[union-attr]
pandas/io/pytables.py:4029:                blocks.extend(mgr.blocks)  # type: ignore[union-attr]
pandas/io/pickle.py:107:                pickle.dumps(obj, protocol=protocol)  # type: ignore[arg-type]
pandas/io/pickle.py:112:                obj, handles.handle, protocol=protocol  # type: ignore[arg-type]
pandas/io/pickle.py:207:                    return pickle.load(handles.handle)  # type: ignore[arg-type]
pandas/io/excel/_base.py:927:            for extension in cls.supported_extensions  # type: ignore[attr-defined]
pandas/io/excel/_base.py:1003:        zf = zipfile.ZipFile(stream)  # type: ignore[arg-type]
pandas/io/stata.py:914:        self.TYPE_MAP = list(range(251)) + list("bhlfd")  # type: ignore[arg-type]
pandas/io/stata.py:1094:            self.path_or_buf = BytesIO(handles.handle.read())  # type: ignore[arg-type]
pandas/io/stata.py:2211:            to_write.encode(self._encoding)  # type: ignore[arg-type]
pandas/io/stata.py:2218:        self.handles.handle.write(value)  # type: ignore[arg-type]
pandas/io/stata.py:2542:            self.handles.handle.write(bio.getvalue())  # type: ignore[arg-type]
pandas/io/json/_json.py:1045:            )  # type:ignore[misc]
pandas/io/common.py:518:    )  # type: ignore[operator]
pandas/io/common.py:628:                    fileobj=handle,  # type: ignore[arg-type]
pandas/io/common.py:636:                handle,  # type: ignore[arg-type]
pandas/io/common.py:693:            handle,  # type: ignore[arg-type]
pandas/io/common.py:731:class _BytesZipFile(zipfile.ZipFile, BytesIO):  # type: ignore[misc]
pandas/io/common.py:755:        super().__init__(file, mode, **kwargs_zip)  # type: ignore[arg-type]
pandas/io/common.py:852:        wrapped = cast(mmap.mmap, _MMapWrapper(handle))  # type: ignore[arg-type]
pandas/io/parsers/c_parser_wrapper.py:48:            self.handles.handle = self.handles.handle.mmap  # type: ignore[union-attr]
pandas/io/parsers/readers.py:976:        return mapping[engine](self.f, **self.options)  # type: ignore[call-arg]
pandas/io/parsers/python_parser.py:243:        self.data = reader  # type: ignore[assignment]
pandas/io/parsers/python_parser.py:301:            size = self.chunksize  # type: ignore[attr-defined]

```

</details>