How to compare and test specific key in list of dictionaries using Python and Pytest

Question

I have a list of dictionary items and i want to compare specific keys in the list of dictionaries.I am trying the following code and it is working fine, but i see duplication of code . Is there anyway i can optimize the code .

My data structure is as follows

[{
        "title": "x86_64",
        "type": "info",
        "list_type": ["2016-9131", "2016-9147", "2016-9444"]

    }, {
        "title": "x_64",
        "type": "info",
        "list_type": ["2036-9131", "2026-9147", "2046-9444"],
    }
]

python code below

import json,pytest

with open('expected_resuts.json') as expected_result:
    expected_results=json.load(expected_result)

with open('actual_results.json') as actual_result:
    actual_results=json.load(actual_result)

expected_title_list=[]
expected_title_list=[]
expected_name=[]
actual_name=[]

for item in expected_results:
    expected_title_list.append(item['title'])

for item in actual_results:
    expected_title_list.append(item['title'])

for item in expected_results:
    expected_name.append(item['type'])

for item in actual_results:
    actual_name.append(item['type'])


def test_title_list():
    assert expected_title_list==expected_title_list

def test_name():
    assert actual_name==expected_name

Answer 1

You could improve it quite a lot just by using list comprehensions. You could also move variables like expected_vpk_list inside the test that needs it (to avoid creating too many global variables). Example below:

import json, pytest

with open('expected_results.json') as expected_result:
    expected_results = json.load(expected_result)

with open('actual_results.json') as actual_result:
    actual_results = json.load(actual_result)

def test_vpk_list():
    expected_vpk_list = [result['vpk'] for result in expected_results]
    actual_vpk_list = [result['vpk'] for result in actual_results]
    assert actual_vpk_list == expected_vpk_list

def test_patch_title():
    expected_patch_title = [result['patchTitle'] for result in expected_results]
    actual_patch_title = [result['patchTitle'] for result in actual_results]
    assert actual_patch_title == expected_patch_title

---

UPDATE: These tests can be merged by using parametrize as shown below:

@pytest.mark.parametrize('key', [
    'vpk',
    'patchTitle',
])
def test_key_from_results(key):
    expected_values = [result[key] for result in expected_results]
    actual_values = [result[key] for result in actual_results]
    assert expected_values == actual_values