[ArrowStringArray] PERF: small perf gain for object fallback (pandas-…

…dev#41338)
ricoyudog · May 6, 2021 · 4af3eed · 4af3eed
1 parent ae5fe34
commit 4af3eed
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/pandas/core/arrays/string_arrow.py b/pandas/core/arrays/string_arrow.py
@@ -792,7 +792,8 @@ def _str_map(self, f, na_value=None, dtype: Dtype | None = None):
             result = lib.map_infer_mask(
                 arr, f, mask.view("uint8"), convert=False, na_value=na_value
             )
-            return self._from_sequence(result)
+            result = pa.array(result, mask=mask, type=pa.string(), from_pandas=True)
+            return type(self)(result)
         else:
             # This is when the result type is object. We reach this when
             # -> We know the result type is truly object (e.g. .encode returns bytes