Try adapt 'unicode' fixture

Author: h-vetinari

pandas/tests/test_strings.py

@@ -85,7 +85,7 @@ def all_string_methods(request):
 
 _all_allowed_skipna_inferred_dtypes = [
     ('string', ['a', np.nan, 'c']),
-    ('unicode' if not PY3 else 'string', ['á', np.nan, 'c']),
+    ('unicode' if not PY3 else 'string', [u('a'), np.nan, u('c')]),
     ('bytes' if PY3 else 'string', [b'a', np.nan, b'c']),
     ('empty', [np.nan, np.nan, np.nan]),
     ('mixed-integer', ['a', np.nan, 2]),