Pytest - passing test for the Fibonacci function

from fibonacci import fib


def test_fib():
    assert fib(7)  == 8
    assert fib(10) == 34
    assert fib(42) == 165580141

We can run the tests in two different ways. The regular would be to type in pytest and the name of the test file. In some setups this might not work and then we can also run python -m pytest and the name of the test file.

pytest test_fibonacci_with_pytest.py
python -m pytest test_fibonacci_with_pytest.py

============================= test session starts ==============================
platform linux -- Python 3.13.7, pytest-9.0.2, pluggy-1.6.0
rootdir: /home/gabor/github/code-maven.com/python.code-maven.com
configfile: pyproject.toml
plugins: anyio-4.12.0, cov-7.0.0
collected 1 item

test_fibonacci_with_pytest.py .                                          [100%]

============================== 1 passed in 0.05s ===============================

The top of the output shows some information about the environment, (version numbers, plugins) then “collected” tells us how many test-cases were found by pytest. Each test function is one test case.

Then we see the name of the test file and a single dot indicating that there was one test-case and it was successful.

After the test run we could also see the exit code of the program by typing in echo $? on Linux or Mac or echo %ERRORLEVEL% on Windows.

$ echo $?
0

> echo %ERRORLEVEL%
0