assertEqual compare json objects raise error because of 'quote' in Python

Question

I have a function which converts a dataframe to a json object

def convert_to_json(dataframe):
   
    output_json = json.dumps({"XYZ": dataframe.to_dict('records')}, default=str)

    return output_json

Then in my unit test:

    def test_convert_to_json(self):
       test_data = {
            'col_2': ['2018-03-02', '2018-03-01'],
            'col_3': ['12345678', '12345678'],
            'col_4': [31, 31],
            'col_5': [0.035133, 0.035133]
          }
       test_df = pd.DataFrame(test_data)
       test_json = xxx.convert_to_json(self.test_df)
       
       expected_json = {"XYZ": [{"col_2": "2018-03-02", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}, {"col_2": "2018-03-01", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}]}
        
       self.assertEqual(test_json, expected_json)

This test failed because of the quote:

Ran 1 test in 0.008s

FAILED (failures=1)


{'XYZ': [{'col_2': '2018-03-02',
                                 'col_3': '12345678',
                                 'col_4': 31,
                                 'col_5': 0.035133},
                                {'col_2': '2018-03-01',
                                 'col_3': '12345678',
                                 'col_4': 31,
                                 'col_5': 0.035133}]} != {"XYZ": [{"col_2": "2018-03-02", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}, {"col_2": "2018-03-01", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}]}

However, if I print out the value for test_json and expected_json, they both use double quotes:

{"XYZ": [{"col_2": "2018-03-02", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}, {"col_2": "2018-03-01", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}]}

{"XYZ": [{"col_2": "2018-03-02", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}, {"col_2": "2018-03-01", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}]}

I'm new to unit test, very confused about the code behavior, can someone help please? Thanks.

Answer 1

As @khelwood mentioned, you are comparing a string and a dict. I would suggest you to change the expected_json variable to string (do it only if that is really what you are expecting to get from the tested function, of course).

Try this:

expected_json = '{"XYZ": [{"col_2": "2018-03-02", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}, {"col_2": "2018-03-01", "col_3": "12345678", "col_4": 31, "col_5": 0.035133}]}'

(Note the single quotes surrounding the value)