TYP: scipy-stubs (#62331)

Author: jorenham

environment.yml

@@ -91,6 +91,9 @@ dependencies:
   - sphinx
   - sphinx-design
   - sphinx-copybutton
+
+  # static typing
+  - scipy-stubs
   - types-python-dateutil
   - types-PyMySQL
   - types-pytz

pandas/core/missing.py

@@ -45,6 +45,7 @@
 )
 
 if TYPE_CHECKING:
+    from collections.abc import Callable
     from typing import TypeAlias
 
     from pandas import Index
@@ -548,7 +549,7 @@ def _interpolate_scipy_wrapper(
     new_x = np.asarray(new_x)
 
     # ignores some kwargs that could be passed along.
-    alt_methods = {
+    alt_methods: dict[str, Callable[..., np.ndarray]] = {
         "barycentric": interpolate.barycentric_interpolate,
         "krogh": interpolate.krogh_interpolate,
         "from_derivatives": _from_derivatives,
@@ -566,6 +567,7 @@ def _interpolate_scipy_wrapper(
         "cubic",
         "polynomial",
     ]
+    terp: Callable[..., np.ndarray] | None
     if method in interp1d_methods:
         if method == "polynomial":
             kind = order

pandas/plotting/_matplotlib/hist.py

@@ -260,7 +260,7 @@ def _get_ind(y: np.ndarray, ind):
 
     @classmethod
     # error: Signature of "_plot" incompatible with supertype "MPLPlot"
-    def _plot(  #  type: ignore[override]
+    def _plot(  # type: ignore[override]
         cls,
         ax: Axes,
         y: np.ndarray,
@@ -277,6 +277,8 @@ def _plot(  #  type: ignore[override]
         y = remove_na_arraylike(y)
         gkde = gaussian_kde(y, bw_method=bw_method, weights=weights)
 
+        # gaussian_kde.evaluate(None) raises TypeError, so pyright requires this check
+        assert ind is not None
         y = gkde.evaluate(ind)
         lines = MPLPlot._plot(ax, ind, y, style=style, **kwds)
         return lines

requirements-dev.txt

@@ -66,6 +66,7 @@ pytest-cython
 sphinx
 sphinx-design
 sphinx-copybutton
+scipy-stubs
 types-python-dateutil
 types-PyMySQL
 types-pytz