pytest fixtures#
A particular useful thing in pytest are fixtures. These are default or custom values that can be passed as parameters to your tests.
For instance, pytest has by default a tmp_path fixture, which can directly be passed to your test:
from pathlib import Path
def test_something(tmp_path)
# save our file in a temporary folder created by pytest
save_something(tmp_path, name='myfile.txt')
# check that save_something worked
assert (tmp_path / 'myfile.txt').exists()
# do more checks about the correctness of the file
...
# we don't need to delete the file, pytest will take care of the folder!
This is really powerful!
You can also create your own fixtures:
@pytest.fixture
def unhappy_european_swallow():
return Swallow(species="european", cargo_weight=0.45)
def test_swallow_going_home(unhappy_european_swallow):
"""Test that unhappy European swallows are going home."""
assert unhappy_european_swallow.get_speed() < 0
The conftest.py file#
Your fixtures can be shared across multiple test files by simply defining them in a separate file called conftest.py:
File Structure
src/
└── pydev_tutorial/
├── __init__.py
└── swallow.py
tests/
├── __init__.py
├── conftest.py
└── test_swallow.py
updated: 2023-04-20
