Fix: DataFrame.replace incompatible with type "dict[str, dict[int, int]]" (pandas-dev#1164)

* add failing test

* fix

* use HashableT3 for value/regex

Author: MarcoGorelli

pandas-stubs/_typing.pyi

@@ -740,7 +740,7 @@ ReplaceValue: TypeAlias = (
     | Pattern
     | NAType
     | Sequence[Scalar | Pattern]
-    | Mapping[Hashable, Scalar]
+    | Mapping[HashableT, ScalarT]
     | Series[Any]
     | None
 )

pandas-stubs/core/frame.pyi

@@ -92,6 +92,7 @@ from pandas._typing import (
     HashableT,
     HashableT1,
     HashableT2,
+    HashableT3,
     IgnoreRaise,
     IndexingInt,
     IndexLabel,
@@ -797,20 +798,20 @@ class DataFrame(NDFrame, OpsMixin, _GetItemHack):
     @overload
     def replace(
         self,
-        to_replace: ReplaceValue | Mapping[Hashable, ReplaceValue] = ...,
-        value: ReplaceValue | Mapping[Hashable, ReplaceValue] = ...,
+        to_replace: ReplaceValue | Mapping[HashableT2, ReplaceValue] = ...,
+        value: ReplaceValue | Mapping[HashableT3, ReplaceValue] = ...,
         *,
         inplace: Literal[True],
-        regex: ReplaceValue | Mapping[Hashable, ReplaceValue] = ...,
+        regex: ReplaceValue | Mapping[HashableT3, ReplaceValue] = ...,
     ) -> None: ...
     @overload
     def replace(
         self,
-        to_replace: ReplaceValue | Mapping[Hashable, ReplaceValue] = ...,
-        value: ReplaceValue | Mapping[Hashable, ReplaceValue] = ...,
+        to_replace: ReplaceValue | Mapping[HashableT2, ReplaceValue] = ...,
+        value: ReplaceValue | Mapping[HashableT3, ReplaceValue] = ...,
         *,
         inplace: Literal[False] = ...,
-        regex: ReplaceValue | Mapping[Hashable, ReplaceValue] = ...,
+        regex: ReplaceValue | Mapping[HashableT3, ReplaceValue] = ...,
     ) -> Self: ...
     def shift(
         self,

tests/test_frame.py

@@ -2574,8 +2574,10 @@ def test_types_replace() -> None:
 
 
 def test_dataframe_replace() -> None:
-    df = pd.DataFrame({"col1": ["a", "ab", "ba"]})
+    df = pd.DataFrame({"col1": ["a", "ab", "ba"], "col2": [0, 1, 2]})
     pattern = re.compile(r"^a.*")
+    replace_dict_scalar = {0: 1}
+    replace_dict_per_column = {"col2": {0: 1}}
     check(assert_type(df.replace("a", "x"), pd.DataFrame), pd.DataFrame)
     check(assert_type(df.replace(pattern, "x"), pd.DataFrame), pd.DataFrame)
     check(assert_type(df.replace("a", "x", regex=True), pd.DataFrame), pd.DataFrame)
@@ -2592,6 +2594,7 @@ def test_dataframe_replace() -> None:
     )
 
     check(assert_type(df.replace({"a": "x"}), pd.DataFrame), pd.DataFrame)
+    check(assert_type(df.replace(replace_dict_scalar), pd.DataFrame), pd.DataFrame)
     check(assert_type(df.replace({pattern: "x"}), pd.DataFrame), pd.DataFrame)
     check(assert_type(df.replace(pd.Series({"a": "x"})), pd.DataFrame), pd.DataFrame)
     check(assert_type(df.replace(regex={"a": "x"}), pd.DataFrame), pd.DataFrame)
@@ -2670,6 +2673,7 @@ def test_dataframe_replace() -> None:
     )
 
     check(assert_type(df.replace({"col1": {"a": "x"}}), pd.DataFrame), pd.DataFrame)
+    check(assert_type(df.replace(replace_dict_per_column), pd.DataFrame), pd.DataFrame)
     check(assert_type(df.replace({"col1": {pattern: "x"}}), pd.DataFrame), pd.DataFrame)
     check(
         assert_type(df.replace({"col1": pd.Series({"a": "x"})}), pd.DataFrame),

tests/test_series.py

@@ -1448,12 +1448,17 @@ def test_types_replace() -> None:
 def test_series_replace() -> None:
     s: pd.Series[str] = pd.DataFrame({"col1": ["a", "ab", "ba"]})["col1"]
     pattern = re.compile(r"^a.*")
+    replace_dict = {"a": "b"}
     check(assert_type(s.replace("a", "x"), "pd.Series[str]"), pd.Series)
     check(assert_type(s.replace(pattern, "x"), "pd.Series[str]"), pd.Series)
     check(
         assert_type(s.replace({"a": "z"}), "pd.Series[str]"),
         pd.Series,
     )
+    check(
+        assert_type(s.replace(replace_dict), "pd.Series[str]"),
+        pd.Series,
+    )
     check(
         assert_type(s.replace(pd.Series({"a": "z"})), "pd.Series[str]"),
         pd.Series,