MAINT: Apply ruff rule RUF013

RUF013 PEP 484 prohibits implicit `Optional`

Author: DimitriPapadopoulos

numpy/core/_utils.py

@@ -1,7 +1,8 @@
 import warnings
+from typing import Optional
 
 
-def _raise_warning(attr: str, submodule: str = None) -> None:
+def _raise_warning(attr: str, submodule: Optional[str] = None) -> None:
     new_module = "numpy._core"
     old_module = "numpy.core"
     if submodule is not None:

numpy/lib/_function_base_impl.py

@@ -30,6 +30,7 @@
 
 # needed in this module for compatibility
 from numpy.lib._histograms_impl import histogram, histogramdd  # noqa: F401
+from typing import Optional
 
 
 array_function_dispatch = functools.partial(
@@ -4665,7 +4666,7 @@ def _quantile_ureduce_func(
         a: np.array,
         q: np.array,
         weights: np.array,
-        axis: int = None,
+        axis: Optional[int] = None,
         out=None,
         overwrite_input: bool = False,
         method="linear",

numpy/lib/_nanfunctions_impl.py

@@ -27,6 +27,7 @@
 from numpy.lib import _function_base_impl as fnb
 from numpy.lib._function_base_impl import _weights_are_valid
 from numpy._core import overrides
+from typing import Optional
 
 
 array_function_dispatch = functools.partial(
@@ -1662,7 +1663,7 @@ def _nanquantile_ureduce_func(
         a: np.array,
         q: np.array,
         weights: np.array,
-        axis: int = None,
+        axis: Optional[int] = None,
         out=None,
         overwrite_input: bool = False,
         method="linear",