Could you explain what is meant by a fixture in the pytest library?

In pytest, a fixture is a special function that prepares the test environment and provides tests with necessary data or objects. Fixtures help avoid code duplication and enable reuse of setup.

For example, a fixture can create a database connection, start a server, or generate test data, and then automatically clean up resources after the test.

Example of a fixture:

import pytest

@pytest.fixture
def sample_list():
    return [1, 2, 3]


def test_sum(sample_list):
    assert sum(sample_list) == 6

Here, sample_list is a fixture that is passed to the test as a parameter.