move specific test to tests/arrays

Author: kotamatsuoka

pandas/tests/arrays/string_/test_string.py

@@ -277,3 +277,12 @@ def test_value_counts_na():
     result = arr.value_counts(dropna=True)
     expected = pd.Series([2, 1], index=["a", "b"], dtype="Int64")
     tm.assert_series_equal(result, expected)
+
+
+def test_memory_usage():
+    # GH 33963
+    series = pd.Series(['a', 'b', 'c'], dtype="string")
+
+    assert (
+        0 < series.nbytes <= series.memory_usage() < series.memory_usage(deep=True)
+    )

pandas/tests/extension/test_string.py

@@ -85,14 +85,6 @@ class TestMethods(base.BaseMethodsTests):
     def test_value_counts(self, all_data, dropna):
         return super().test_value_counts(all_data, dropna)
 
-    def test_memory_usage(self, data):
-        # GH 33963
-        series = pd.Series(data, dtype="string")
-
-        assert (
-            0 < series.nbytes <= series.memory_usage() < series.memory_usage(deep=True)
-        )
-
 
 class TestCasting(base.BaseCastingTests):
     pass