REF (string): de-duplicate _str_contains (pandas-dev#59709)

* REF: de-duplicate _str_contains

* pyright ignore

Author: jbrockmendel

pandas/core/arrays/_arrow_string_mixins.py

@@ -190,3 +190,18 @@ def _str_istitle(self):
     def _str_isupper(self):
         result = pc.utf8_is_upper(self._pa_array)
         return self._convert_bool_result(result)
+
+    def _str_contains(
+        self, pat, case: bool = True, flags: int = 0, na=None, regex: bool = True
+    ):
+        if flags:
+            raise NotImplementedError(f"contains not implemented with {flags=}")
+
+        if regex:
+            pa_contains = pc.match_substring_regex
+        else:
+            pa_contains = pc.match_substring
+        result = pa_contains(self._pa_array, pat, ignore_case=not case)
+        if not isna(na):  # pyright: ignore [reportGeneralTypeIssues]
+            result = result.fill_null(na)
+        return self._convert_bool_result(result)

pandas/core/arrays/arrow/array.py

@@ -2322,21 +2322,6 @@ def _str_count(self, pat: str, flags: int = 0) -> Self:
             raise NotImplementedError(f"count not implemented with {flags=}")
         return type(self)(pc.count_substring_regex(self._pa_array, pat))
 
-    def _str_contains(
-        self, pat, case: bool = True, flags: int = 0, na=None, regex: bool = True
-    ) -> Self:
-        if flags:
-            raise NotImplementedError(f"contains not implemented with {flags=}")
-
-        if regex:
-            pa_contains = pc.match_substring_regex
-        else:
-            pa_contains = pc.match_substring
-        result = pa_contains(self._pa_array, pat, ignore_case=not case)
-        if not isna(na):
-            result = result.fill_null(na)
-        return type(self)(result)
-
     def _result_converter(self, result):
         return type(self)(result)
 

pandas/core/arrays/string_arrow.py

@@ -223,10 +223,8 @@ def insert(self, loc: int, item) -> ArrowStringArray:
             raise TypeError("Scalar must be NA or str")
         return super().insert(loc, item)
 
-    def _convert_bool_result(self, values, na=None):
+    def _convert_bool_result(self, values):
         if self.dtype.na_value is np.nan:
-            if not isna(na):
-                values = values.fill_null(bool(na))
             return ArrowExtensionArray(values).to_numpy(na_value=np.nan)
         return BooleanDtype().__from_arrow__(values)
 
@@ -304,11 +302,6 @@ def _str_contains(
                 fallback_performancewarning()
             return super()._str_contains(pat, case, flags, na, regex)
 
-        if regex:
-            result = pc.match_substring_regex(self._pa_array, pat, ignore_case=not case)
-        else:
-            result = pc.match_substring(self._pa_array, pat, ignore_case=not case)
-        result = self._convert_bool_result(result, na=na)
         if not isna(na):
             if not isinstance(na, bool):
                 # GH#59561
@@ -318,8 +311,9 @@ def _str_contains(
                     FutureWarning,
                     stacklevel=find_stack_level(),
                 )
-            result[isna(result)] = bool(na)
-        return result
+                na = bool(na)
+
+        return ArrowStringArrayMixin._str_contains(self, pat, case, flags, na, regex)
 
     def _str_replace(
         self,