Changed to string

Author: shubham11941140

pandas/tests/frame/methods/test_replace.py

@@ -1512,7 +1512,7 @@ def test_replace_regex_dtype_frame(self, regex):
         result_df1 = df1.replace(to_replace="0", value=1, regex=regex)
         tm.assert_frame_equal(result_df1, expected_df1)
 
-        df2 = DataFrame({"A": ["0"], "B": [np.NaN]})
-        expected_df2 = DataFrame({"A": [1], "B": [np.NaN]})
+        df2 = DataFrame({"A": ["0"], "B": ["1"]})
+        expected_df2 = DataFrame({"A": [1], "B": ["1"]})
         result_df2 = df2.replace(to_replace="0", value=1, regex=regex)
         tm.assert_frame_equal(result_df2, expected_df2)