fix: test_pandas_column_datatype data type

Author: NguyenHoangSon96

tests/test_FluxCSVParser.py

@@ -251,11 +251,11 @@ def test_pandas_column_datatype(self):
                              response_metadata_mode=FluxResponseMetadataMode.full)
         df = list(parser.generator())[0]
         self.assertEqual(13, df.dtypes.__len__())
-        self.assertEqual('object', df.dtypes['result'].name)
+        self.assertEqual('str', df.dtypes['result'].name)
         self.assertEqual('int64', df.dtypes['table'].name)
-        self.assertIn('datetime64[ns,', df.dtypes['_start'].name)
-        self.assertIn('datetime64[ns,', df.dtypes['_stop'].name)
-        self.assertEqual('object', df.dtypes['_field'].name)
+        self.assertIn('datetime64[us,', df.dtypes['_start'].name)
+        self.assertIn('datetime64[us,', df.dtypes['_stop'].name)
+        self.assertEqual('str', df.dtypes['_field'].name)
         self.assertEqual('object', df.dtypes['_measurement'].name)
         self.assertEqual('object', df.dtypes['host'].name)
         self.assertEqual('object', df.dtypes['region'].name)