fix implementation

Author: rhshadrach

pandas/io/pytables.py

@@ -5235,6 +5235,7 @@ def _unconvert_string_array(
         if isinstance(data[0], bytes):
             ser = Series(data, copy=False).str.decode(encoding, errors=errors)
             data = ser.to_numpy()
+            data.flags.writeable = True
         else:
             data = data.astype(dtype, copy=False).astype(object, copy=False)
 

pandas/tests/strings/test_strings.py

@@ -95,6 +95,7 @@ def test_repeat_with_null(any_string_dtype, arg, repeat):
 
 def test_empty_str_methods(any_string_dtype):
     empty_str = empty = Series(dtype=any_string_dtype)
+    empty_inferred_str = Series(dtype="str")
     if is_object_or_nan_string_dtype(any_string_dtype):
         empty_int = Series(dtype="int64")
         empty_bool = Series(dtype=bool)
@@ -154,7 +155,7 @@ def test_empty_str_methods(any_string_dtype):
     tm.assert_series_equal(empty_str, empty.str.rstrip())
     tm.assert_series_equal(empty_str, empty.str.wrap(42))
     tm.assert_series_equal(empty_str, empty.str.get(0))
-    tm.assert_series_equal(empty_object, empty_bytes.str.decode("ascii"))
+    tm.assert_series_equal(empty_inferred_str, empty_bytes.str.decode("ascii"))
     tm.assert_series_equal(empty_bytes, empty.str.encode("ascii"))
     # ismethods should always return boolean (GH 29624)
     tm.assert_series_equal(empty_bool, empty.str.isalnum())
@@ -596,7 +597,7 @@ def test_decode_errors_kwarg():
         ser.str.decode("cp1252")
 
     result = ser.str.decode("cp1252", "ignore")
-    expected = ser.map(lambda x: x.decode("cp1252", "ignore")).astype(object)
+    expected = ser.map(lambda x: x.decode("cp1252", "ignore")).astype("str")
     tm.assert_series_equal(result, expected)
 
 
@@ -751,5 +752,5 @@ def test_get_with_dict_label():
 def test_series_str_decode():
     # GH 22613
     result = Series([b"x", b"y"]).str.decode(encoding="UTF-8", errors="strict")
-    expected = Series(["x", "y"], dtype="object")
+    expected = Series(["x", "y"], dtype="str")
     tm.assert_series_equal(result, expected)