CLN: add typing for dtype arg in directories core/indexes and core/strings (GH38808)

pandas/core/indexes/category.py

@@ -7,7 +7,7 @@
 
 from pandas._libs import index as libindex
 from pandas._libs.lib import no_default
-from pandas._typing import ArrayLike, Label
+from pandas._typing import ArrayLike, Dtype, Label
 from pandas.util._decorators import Appender, doc
 
 from pandas.core.dtypes.common import (
@@ -180,7 +180,13 @@ def _engine_type(self):
     # Constructors
 
     def __new__(
-        cls, data=None, categories=None, ordered=None, dtype=None, copy=False, name=None
+        cls,
+        data=None,
+        categories=None,
+        ordered=None,
+        dtype: Optional[Dtype] = None,
+        copy=False,
+        name=None,
     ):
 
         name = maybe_extract_name(name, data, cls)

pandas/core/indexes/datetimes.py

@@ -14,7 +14,7 @@
     to_offset,
 )
 from pandas._libs.tslibs.offsets import prefix_mapping
-from pandas._typing import DtypeObj
+from pandas._typing import Dtype, DtypeObj
 from pandas.errors import InvalidIndexError
 from pandas.util._decorators import cache_readonly, doc
 
@@ -289,7 +289,7 @@ def __new__(
         ambiguous="raise",
         dayfirst=False,
         yearfirst=False,
-        dtype=None,
+        dtype: Optional[Dtype] = None,
         copy=False,
         name=None,
     ):

pandas/core/indexes/interval.py

@@ -11,7 +11,7 @@
 from pandas._libs import lib
 from pandas._libs.interval import Interval, IntervalMixin, IntervalTree
 from pandas._libs.tslibs import BaseOffset, Timedelta, Timestamp, to_offset
-from pandas._typing import DtypeObj, Label
+from pandas._typing import Dtype, DtypeObj, Label
 from pandas.errors import InvalidIndexError
 from pandas.util._decorators import Appender, cache_readonly
 from pandas.util._exceptions import rewrite_exception
@@ -192,7 +192,7 @@ def __new__(
         cls,
         data,
         closed=None,
-        dtype=None,
+        dtype: Optional[Dtype] = None,
         copy: bool = False,
         name=None,
         verify_integrity: bool = True,
@@ -249,7 +249,12 @@ def _simple_new(cls, array: IntervalArray, name: Label = None):
         }
     )
     def from_breaks(
-        cls, breaks, closed: str = "right", name=None, copy: bool = False, dtype=None
+        cls,
+        breaks,
+        closed: str = "right",
+        name=None,
+        copy: bool = False,
+        dtype: Optional[Dtype] = None,
     ):
         with rewrite_exception("IntervalArray", cls.__name__):
             array = IntervalArray.from_breaks(
@@ -281,7 +286,7 @@ def from_arrays(
         closed: str = "right",
         name=None,
         copy: bool = False,
-        dtype=None,
+        dtype: Optional[Dtype] = None,
     ):
         with rewrite_exception("IntervalArray", cls.__name__):
             array = IntervalArray.from_arrays(
@@ -307,7 +312,12 @@ def from_arrays(
         }
     )
     def from_tuples(
-        cls, data, closed: str = "right", name=None, copy: bool = False, dtype=None
+        cls,
+        data,
+        closed: str = "right",
+        name=None,
+        copy: bool = False,
+        dtype: Optional[Dtype] = None,
     ):
         with rewrite_exception("IntervalArray", cls.__name__):
             arr = IntervalArray.from_tuples(data, closed=closed, copy=copy, dtype=dtype)

pandas/core/indexes/numeric.py

@@ -1,4 +1,4 @@
-from typing import Any
+from typing import Any, Optional
 import warnings
 
 import numpy as np
@@ -45,7 +45,7 @@ class NumericIndex(Index):
     _is_numeric_dtype = True
     _can_hold_strings = False
 
-    def __new__(cls, data=None, dtype=None, copy=False, name=None):
+    def __new__(cls, data=None, dtype: Optional[Dtype] = None, copy=False, name=None):
         name = maybe_extract_name(name, data, cls)
 
         subarr = cls._ensure_array(data, dtype, copy)

pandas/core/indexes/period.py

@@ -1,13 +1,13 @@
 from datetime import datetime, timedelta
-from typing import Any
+from typing import Any, Optional
 import warnings
 
 import numpy as np
 
 from pandas._libs import index as libindex, lib
 from pandas._libs.tslibs import BaseOffset, Period, Resolution, Tick
 from pandas._libs.tslibs.parsing import DateParseError, parse_time_string
-from pandas._typing import DtypeObj
+from pandas._typing import Dtype, DtypeObj
 from pandas.errors import InvalidIndexError
 from pandas.util._decorators import cache_readonly, doc
 
@@ -190,7 +190,7 @@ def __new__(
         data=None,
         ordinal=None,
         freq=None,
-        dtype=None,
+        dtype: Optional[Dtype] = None,
         copy=False,
         name=None,
         **fields,

pandas/core/indexes/range.py

@@ -8,7 +8,7 @@
 
 from pandas._libs import index as libindex
 from pandas._libs.lib import no_default
-from pandas._typing import Label
+from pandas._typing import Dtype, Label
 from pandas.compat.numpy import function as nv
 from pandas.util._decorators import cache_readonly, doc
 
@@ -83,7 +83,13 @@ class RangeIndex(Int64Index):
     # Constructors
 
     def __new__(
-        cls, start=None, stop=None, step=None, dtype=None, copy=False, name=None
+        cls,
+        start=None,
+        stop=None,
+        step=None,
+        dtype: Optional[Dtype] = None,
+        copy=False,
+        name=None,
     ):
 
         cls._validate_dtype(dtype)
@@ -113,7 +119,9 @@ def __new__(
         return cls._simple_new(rng, name=name)
 
     @classmethod
-    def from_range(cls, data: range, name=None, dtype=None) -> "RangeIndex":
+    def from_range(
+        cls, data: range, name=None, dtype: Optional[Dtype] = None
+    ) -> "RangeIndex":
         """
         Create RangeIndex from a range object.
 
@@ -405,7 +413,7 @@ def _shallow_copy(self, values=None, name: Label = no_default):
         return result
 
     @doc(Int64Index.copy)
-    def copy(self, name=None, deep=False, dtype=None, names=None):
+    def copy(self, name=None, deep=False, dtype: Optional[Dtype] = None, names=None):
         name = self._validate_names(name=name, names=names, deep=deep)[0]
         new_index = self._shallow_copy(name=name)
 

pandas/core/strings/object_array.py

@@ -1,6 +1,6 @@
 import re
 import textwrap
-from typing import Pattern, Set, Union, cast
+from typing import Optional, Pattern, Set, Union, cast
 import unicodedata
 import warnings
 
@@ -9,7 +9,7 @@
 import pandas._libs.lib as lib
 import pandas._libs.missing as libmissing
 import pandas._libs.ops as libops
-from pandas._typing import Scalar
+from pandas._typing import NpDtype, Scalar
 
 from pandas.core.dtypes.common import is_re, is_scalar
 from pandas.core.dtypes.missing import isna
@@ -28,7 +28,7 @@ def __len__(self):
         # For typing, _str_map relies on the object being sized.
         raise NotImplementedError
 
-    def _str_map(self, f, na_value=None, dtype=None):
+    def _str_map(self, f, na_value=None, dtype: Optional[NpDtype] = None):
         """
         Map a callable over valid element of the array.