test: add str.isascii testcase

Author: ujex256

pandas/tests/strings/conftest.py

@@ -68,6 +68,7 @@
             "get_dummies",
             "isalnum",
             "isalpha",
+            "isascii",
             "isdecimal",
             "isdigit",
             "islower",
@@ -97,7 +98,6 @@
 )
 ids, _, _ = zip(*_any_string_method)  # use method name as fixture-id
 missing_methods = {f for f in dir(StringMethods) if not f.startswith("_")} - set(ids)
-
 # test that the above list captures all methods of StringMethods
 assert not missing_methods
 

pandas/tests/strings/test_strings.py

@@ -217,6 +217,19 @@ def test_ismethods(method, expected, any_string_dtype):
     assert list(result) == expected
 
 
+def test_isascii(any_string_dtype):
+    ser = Series(
+        ["a", "bb", "123", "あ", "\n", "", " ", "¼"],
+        dtype=any_string_dtype,
+    )
+    expected_dtype = "bool" if any_string_dtype in object_pyarrow_numpy else "boolean"
+    result = ser.str.isascii()
+    expected = Series(
+        [True, True, True, False, True, True, True, False], dtype=expected_dtype
+    )
+    tm.assert_series_equal(result, expected)
+
+
 @pytest.mark.parametrize(
     "method, expected",
     [