pytest how not to exit the for loop after first item assert fails

Question

I am new to python and pytest. I am trying to assert 2 lists of data. As the first data in the list is not matched, the assertion fails at that point and do not proceed for the next item. However I don't want my execution to stop , but complete the loop and capture the overall assertion results. Can someone help me how to achieve it?

code

def test_compare_database():
        records_src = [(1,James,smith,123),(2,Granpa,smith,124),(3,Linda,smith,123)]
        records_trg = [(1,James,smith,111),(2,Granpa,ron,124),(3,Linda,smith,123)]
        for a, b in zip(records_src, records_trg):
            assert a == b

Output:The first item in the list comparison is failed which is correct. But it stops at that. I would want the whole for loop to run and capture the failed results.

============================= test session starts =============================
collecting ... collected 1 item

main_test.py::test_compare_database FAILED  
def test_compare_database():
            records_src = [(1,James,smith,123),(2,Granpa,smith,124),(3,Linda,smith,123)]
            records_trg = [(1,James,smith,111),(2,Granpa,ron,124),(3,Linda,smith,123)]
            for a, b in zip(records_src, records_trg):
>               assert a == b
E      AssertionError: assert (1,
 'James',
 'Smith',
 123,)
  != (1,
 'James',
 'Smith',
 111,)

Answer 1

You can use parametrized test to create multiple tests based on the data, so each pair of tuples will be asserted separately in a different test

def data_source():
    records_src = [(1, 'James', 'smith', 123), (2, 'Granpa', 'smith', 124), (3, 'Linda', 'smith', 123)]
    records_trg = [(1, 'James', 'smith', 111), (2, 'Granpa', 'ron', 124), (3, 'Linda', 'smith', 123)]
    for a, b in zip(records_src, records_trg):
        yield a, b


@pytest.mark.parametrize('a, b', data_source())
def test_compare_database(a, b):
    assert a == b

Console output:

main_test.py::test_compare_database[a0-b0] FAILED                     [ 33%]
Tests\main_test.py:33 (test_compare_database[a0-b0])
(1, 'James', 'smith', 123) != (1, 'James', 'smith', 111)

Expected :(1, 'James', 'smith', 111)
Actual   :(1, 'James', 'smith', 123)
<Click to see difference>

a = (1, 'James', 'smith', 123), b = (1, 'James', 'smith', 111)

    @pytest.mark.parametrize('a, b', data_source())
    def test_compare_database(a, b):
>       assert a == b
E       AssertionError: assert (1, 'James', 'smith', 123) == (1, 'James', 'smith', 111)

main_test.py:36: AssertionError
FAILED                     [ 66%]
Tests\main_test.py:33 (test_compare_database[a1-b1])
(2, 'Granpa', 'smith', 124) != (2, 'Granpa', 'ron', 124)

Expected :(2, 'Granpa', 'ron', 124)
Actual   :(2, 'Granpa', 'smith', 124)
<Click to see difference>

a = (2, 'Granpa', 'smith', 124), b = (2, 'Granpa', 'ron', 124)

    @pytest.mark.parametrize('a, b', data_source())
    def test_compare_database(a, b):
>       assert a == b
E       AssertionError: assert (2, 'Granpa', 'smith', 124) == (2, 'Granpa', 'ron', 124)

main_test.py:36: AssertionError
PASSED                     [100%]