BUG: fix kwargs in Styler.where (#40845)

Author: attack68

doc/source/whatsnew/v1.3.0.rst

@@ -831,6 +831,7 @@ Other
 - Bug in :meth:`Styler.background_gradient` where text-color was not determined correctly (:issue:`39888`)
 - Bug in :class:`Styler` where multiple elements in CSS-selectors were not correctly added to ``table_styles`` (:issue:`39942`)
 - Bug in :class:`.Styler` where copying from Jupyter dropped top left cell and misaligned headers (:issue:`12147`)
+- Bug in :class:`.Styler.where` where ``kwargs`` were not passed to the applicable callable (:issue:`40845`)
 - Bug in :meth:`DataFrame.equals`, :meth:`Series.equals`, :meth:`Index.equals` with object-dtype containing ``np.datetime64("NaT")`` or ``np.timedelta64("NaT")`` (:issue:`39650`)
 - Bug in :func:`pandas.util.show_versions` where console JSON output was not proper JSON (:issue:`39701`)
 - Bug in :meth:`DataFrame.convert_dtypes` incorrectly raised ValueError when called on an empty DataFrame (:issue:`40393`)

pandas/io/formats/style.py

@@ -1086,7 +1086,8 @@ def where(
         Parameters
         ----------
         cond : callable
-            ``cond`` should take a scalar and return a boolean.
+            ``cond`` should take a scalar, and optional keyword arguments, and return
+            a boolean.
         value : str
             Applied when ``cond`` returns true.
         other : str
@@ -1117,7 +1118,8 @@ def where(
             other = ""
 
         return self.applymap(
-            lambda val: value if cond(val) else other, subset=subset, **kwargs
+            lambda val: value if cond(val, **kwargs) else other,
+            subset=subset,
         )
 
     def set_precision(self, precision: int) -> Styler:

pandas/tests/io/formats/style/test_style.py

@@ -557,6 +557,21 @@ def g(x):
             expected = self.df.style.applymap(g, subset=slice_)._compute().ctx
             assert result == expected
 
+    def test_where_kwargs(self):
+        df = DataFrame([[1, 2], [3, 4]])
+
+        def f(x, val):
+            return x > val
+
+        result = df.style.where(f, "color:green;", "color:red;", val=2)._compute().ctx
+        expected = {
+            (0, 0): [("color", "red")],
+            (0, 1): [("color", "red")],
+            (1, 0): [("color", "green")],
+            (1, 1): [("color", "green")],
+        }
+        assert result == expected
+
     def test_empty(self):
         df = DataFrame({"A": [1, 0]})
         s = df.style