REF (string): rename result converter methods (#59626)

Author: jbrockmendel

pandas/core/arrays/_arrow_string_mixins.py

@@ -23,6 +23,14 @@ class ArrowStringArrayMixin:
     def __init__(self, *args, **kwargs) -> None:
         raise NotImplementedError
 
+    def _convert_bool_result(self, result):
+        # Convert a bool-dtype result to the appropriate result type
+        raise NotImplementedError
+
+    def _convert_int_result(self, result):
+        # Convert an integer-dtype result to the appropriate result type
+        raise NotImplementedError
+
     def _str_pad(
         self,
         width: int,

pandas/core/arrays/arrow/array.py

@@ -2311,6 +2311,12 @@ def _apply_elementwise(self, func: Callable) -> list[list[Any]]:
             for chunk in self._pa_array.iterchunks()
         ]
 
+    def _convert_bool_result(self, result):
+        return type(self)(result)
+
+    def _convert_int_result(self, result):
+        return type(self)(result)
+
     def _str_count(self, pat: str, flags: int = 0) -> Self:
         if flags:
             raise NotImplementedError(f"count not implemented with {flags=}")

pandas/core/arrays/string_arrow.py

@@ -221,7 +221,7 @@ def insert(self, loc: int, item) -> ArrowStringArray:
             raise TypeError("Scalar must be NA or str")
         return super().insert(loc, item)
 
-    def _result_converter(self, values, na=None):
+    def _convert_bool_result(self, values, na=None):
         if self.dtype.na_value is np.nan:
             if not isna(na):
                 values = values.fill_null(bool(na))
@@ -293,7 +293,7 @@ def _str_contains(
             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._result_converter(result, na=na)
+        result = self._convert_bool_result(result, na=na)
         if not isna(na):
             result[isna(result)] = bool(na)
         return result
@@ -315,7 +315,7 @@ def _str_startswith(self, pat: str | tuple[str, ...], na: Scalar | None = None):
                     result = pc.or_(result, pc.starts_with(self._pa_array, pattern=p))
         if not isna(na):
             result = result.fill_null(na)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_endswith(self, pat: str | tuple[str, ...], na: Scalar | None = None):
         if isinstance(pat, str):
@@ -334,7 +334,7 @@ def _str_endswith(self, pat: str | tuple[str, ...], na: Scalar | None = None):
                     result = pc.or_(result, pc.ends_with(self._pa_array, pattern=p))
         if not isna(na):
             result = result.fill_null(na)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_replace(
         self,
@@ -387,43 +387,43 @@ def _str_slice(
 
     def _str_isalnum(self):
         result = pc.utf8_is_alnum(self._pa_array)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_isalpha(self):
         result = pc.utf8_is_alpha(self._pa_array)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_isdecimal(self):
         result = pc.utf8_is_decimal(self._pa_array)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_isdigit(self):
         result = pc.utf8_is_digit(self._pa_array)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_islower(self):
         result = pc.utf8_is_lower(self._pa_array)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_isnumeric(self):
         result = pc.utf8_is_numeric(self._pa_array)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_isspace(self):
         result = pc.utf8_is_space(self._pa_array)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_istitle(self):
         result = pc.utf8_is_title(self._pa_array)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_isupper(self):
         result = pc.utf8_is_upper(self._pa_array)
-        return self._result_converter(result)
+        return self._convert_bool_result(result)
 
     def _str_len(self):
         result = pc.utf8_length(self._pa_array)
-        return self._convert_int_dtype(result)
+        return self._convert_int_result(result)
 
     def _str_lower(self) -> Self:
         return type(self)(pc.utf8_lower(self._pa_array))
@@ -470,7 +470,7 @@ def _str_count(self, pat: str, flags: int = 0):
         if flags:
             return super()._str_count(pat, flags)
         result = pc.count_substring_regex(self._pa_array, pat)
-        return self._convert_int_dtype(result)
+        return self._convert_int_result(result)
 
     def _str_find(self, sub: str, start: int = 0, end: int | None = None):
         if start != 0 and end is not None:
@@ -484,7 +484,7 @@ def _str_find(self, sub: str, start: int = 0, end: int | None = None):
             result = pc.find_substring(slices, sub)
         else:
             return super()._str_find(sub, start, end)
-        return self._convert_int_dtype(result)
+        return self._convert_int_result(result)
 
     def _str_get_dummies(self, sep: str = "|"):
         dummies_pa, labels = ArrowExtensionArray(self._pa_array)._str_get_dummies(sep)
@@ -493,7 +493,7 @@ def _str_get_dummies(self, sep: str = "|"):
         dummies = np.vstack(dummies_pa.to_numpy())
         return dummies.astype(np.int64, copy=False), labels
 
-    def _convert_int_dtype(self, result):
+    def _convert_int_result(self, result):
         if self.dtype.na_value is np.nan:
             if isinstance(result, pa.Array):
                 result = result.to_numpy(zero_copy_only=False)
@@ -520,7 +520,7 @@ def _reduce(
 
         result = self._reduce_calc(name, skipna=skipna, keepdims=keepdims, **kwargs)
         if name in ("argmin", "argmax") and isinstance(result, pa.Array):
-            return self._convert_int_dtype(result)
+            return self._convert_int_result(result)
         elif isinstance(result, pa.Array):
             return type(self)(result)
         else:
@@ -538,7 +538,7 @@ def _rank(
         """
         See Series.rank.__doc__.
         """
-        return self._convert_int_dtype(
+        return self._convert_int_result(
             self._rank_calc(
                 axis=axis,
                 method=method,