What are markers in pytest?

In pytest, markers are a way to label tests for grouping, filtering, or changing behavior during execution.

Main uses of markers:

• Grouping tests: for example, marking tests as "slow", "database", "api" and running only specific groups.
• Skipping tests: using the @pytest.mark.skip or @pytest.mark.skipif marker to skip tests under certain conditions.
• Parameterization: although there is a separate mechanism for parameterization, markers can be used for additional logic.

Example of using a marker:

import pytest

@pytest.mark.slow
def test_heavy_computation():
    # a test that takes a lot of time
    assert True

@pytest.mark.skipif(condition, reason="Reason")
def test_skip_example():
    assert False

To run tests with a specific marker, use the command line option:

pytest -m slow

Markers help organize tests and manage their execution in large projects.