test for issue-pandas-dev#34529

Author: Veronur

pandas/tests/frame/test_apply.py

@@ -785,6 +785,13 @@ def non_reducing_function(val):
             df.applymap(func)
             assert values == df.a.to_list()
 
+    def test_apply_with_byte_string(self):  
+        #GH-34529
+        try:
+            df = pd.DataFrame(np.array([b'abcd', b'efgh']), columns=['col'])
+            df.apply(lambda x: x.astype('object'))
+        except OSError as err:
+            tm.external_error_raised(a)
 
 class TestInferOutputShape:
     # the user has supplied an opaque UDF where