changes

Author: JustinZhengBC

pandas/_testing.py

@@ -1106,7 +1106,7 @@ def assert_series_equal(
     check_categorical : bool, default True
         Whether to compare internal Categorical exactly.
     check_category_order : bool, default True
-        Whether to compare category order internal Categoricals
+        Whether to compare category order of internal Categoricals
     obj : str, default 'Series'
         Specify object name being compared, internally used to show appropriate
         assertion message.

pandas/core/arrays/categorical.py

@@ -2412,9 +2412,6 @@ def isin(self, values):
         code_values = code_values[null_mask | (code_values >= 0)]
         return algorithms.isin(self.codes, code_values)
 
-    def replace_list(self, to_replace, value, inplace: bool = False):
-        return self.replace(to_replace, value, inplace)
-
     def replace(self, to_replace, value, inplace: bool = False):
         """
         Replaces all instances of one value with another
@@ -2445,12 +2442,7 @@ def replace(self, to_replace, value, inplace: bool = False):
         inplace = validate_bool_kwarg(inplace, "inplace")
         cat = self if inplace else self.copy()
         if is_list_like(to_replace):
-            if is_list_like(value):
-                if len(to_replace) != len(value):
-                    raise ValueError("to_replace and value must be same length!")
-                replace_dict = dict(zip(to_replace, value))
-            else:
-                replace_dict = {replace_value: value for replace_value in to_replace}
+            replace_dict = {replace_value: value for replace_value in to_replace}
         else:
             replace_dict = {to_replace: value}
         for replace_value, new_value in replace_dict.items():

pandas/tests/arrays/categorical/test_replace.py

@@ -5,25 +5,29 @@
 
 
 @pytest.mark.parametrize(
-    "to_replace,value,expected,check_types",
+    "to_replace,value,expected,check_types,check_categorical",
     [
         # one-to-one
-        (1, 2, [2, 2, 3], True),
-        (1, 4, [4, 2, 3], True),
-        (4, 1, [1, 2, 3], True),
-        (5, 6, [1, 2, 3], True),
+        (1, 2, [2, 2, 3], True, True),
+        (1, 4, [4, 2, 3], True, True),
+        (4, 1, [1, 2, 3], True, True),
+        (5, 6, [1, 2, 3], True, True),
         # many-to-one
-        ([1], 2, [2, 2, 3], True),
-        ([1, 2], 3, [3, 3, 3], True),
-        ([1, 2], 4, [4, 4, 3], True),
-        ((1, 2, 4), 5, [5, 5, 3], True),
-        ((5, 6), 2, [1, 2, 3], True),
+        ([1], 2, [2, 2, 3], True, True),
+        ([1, 2], 3, [3, 3, 3], True, True),
+        ([1, 2], 4, [4, 4, 3], True, True),
+        ((1, 2, 4), 5, [5, 5, 3], True, True),
+        ((5, 6), 2, [1, 2, 3], True, True),
         # many-to-many, handled outside of Categorical and results in separate dtype
-        ([1], [2], [2, 2, 3], False),
-        ([1, 4], [5, 2], [5, 2, 3], False),
+        ([1], [2], [2, 2, 3], False, False),
+        ([1, 4], [5, 2], [5, 2, 3], False, False),
+        # checking categorical causes categories to be sorted, which can crash on mixed dtypes
+        (3, "4", [1, 2, "4"], True, False),
+        ([1, 2, "3"], "5", ["5", "5", 3], True, False)
     ],
 )
-def test_replace(to_replace, value, expected, check_types):
+# GH 31720
+def test_replace(to_replace, value, expected, check_types, check_categorical):
     s = pd.Series([1, 2, 3], dtype="category")
     result = s.replace(to_replace, value)
     expected = pd.Series(expected, dtype="category")
@@ -32,13 +36,13 @@ def test_replace(to_replace, value, expected, check_types):
         expected,
         result,
         check_dtype=check_types,
-        check_categorical=check_types,
+        check_categorical=check_categorical,
         check_category_order=False,
     )
     tm.assert_series_equal(
         expected,
         s,
         check_dtype=check_types,
-        check_categorical=check_types,
+        check_categorical=check_categorical,
         check_category_order=False,
     )