GH1226 PR Feedback

Author: loicdiridollou

pandas-stubs/io/formats/style.pyi

@@ -72,7 +72,10 @@ class Styler(StylerRenderer):
     ) -> None: ...
     def concat(self, other: Styler) -> Styler: ...
     def map(
-        self, func: Callable[[Scalar], str], subset: Subset | None = ..., **kwargs: dict[str, Any]
+        self,
+        func: Callable[[Scalar], str | None],
+        subset: Subset | None = ...,
+        **kwargs: dict[str, Any],
     ) -> Styler: ...
     def set_tooltips(
         self,

tests/test_styler.py

@@ -238,6 +238,11 @@ def test_styler_map() -> None:
     """Test type returned with Styler.map GH1226."""
     df = DataFrame(data={"col1": [1, -2], "col2": [-3, 4]})
     check(
-        assert_type(df.style.map(lambda v: "color: red;" if v < 0 else None), Styler),
+        assert_type(
+            df.style.map(
+                lambda v: "color: red;" if isinstance(v, float) and v < 0 else None
+            ),
+            Styler,
+        ),
         Styler,
     )