fix: test_pandas_column_datatype data type

Author: NguyenHoangSon96

tests/test_FluxCSVParser.py

@@ -256,12 +256,12 @@ def test_pandas_column_datatype(self):
         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)
+        self.assertEqual('str', df.dtypes['_measurement'].name)
+        self.assertEqual('str', df.dtypes['host'].name)
+        self.assertEqual('str', df.dtypes['region'].name)
         self.assertEqual('int64', df.dtypes['value1'].name)
         self.assertEqual('int64', df.dtypes['value2'].name)
-        self.assertEqual('object', df.dtypes['value3'].name)
+        self.assertEqual('str', df.dtypes['value3'].name)
         self.assertEqual('bool', df.dtypes['value4'].name)
         self.assertEqual('float64', df.dtypes['value5'].name)