This will invoke the Python debugger on every failure (or KeyboardInterrupt). Often you might only want to do this for the first failing test to understand a certain failure situation: pytest -x --pdb # drop to PDB on first failure, then end test session pytest --pdb --maxfail=3 # drop to PDB for first three failures

Thanks to pytest’s detailed assertion introspection, you can simply use plain assert statements. See getting-started for more examples. Detailed info on failing assert statements (no need to remember self.assert* names) Auto-discovery of test modules and functions · Modular fixtures for managing small or parametrized long-lived test resources · Can run unittest (or trial) test suites out of the box · Python 3.10+ or PyPy3 ·

$ pytest =========================== test session starts ============================ platform linux -- Python 3.x.y, pytest-9.x.y, pluggy-1.x.y rootdir: /home/sweet/project collected 1 item test_sample.py F [100%] ================================= FAILURES ================================= _______________________________ test_answer ________________________________ def test_answer(): > assert inc(3) == 5 E assert 4 == 5 E + where 4 = inc(3) test_sample.py:6: AssertionError ========================= short test summary info ========================== FAILED test_sample.py::test_answer - assert 4 == 5 ============================ 1 failed in 0.12s =============================

December 8, 2024 - To start using pytest, install ... with Python, such as less boilerplate code, more readable output, and a rich plugin ecosystem. By the end of this tutorial, you’ll understand that: Using pytest requires installing it with pip in a virtual environment to set up the pytest command. pytest allows for less code, easier readability, and more features compared to unittest. Managing test dependencies ...

Managing loading of plugins · Early loading plugins · Disabling plugins · Other ways of calling pytest · Calling pytest through python -m pytest ·

pytest linux command man page: Python testing framework with fixtures and plugins

pytest import mechanisms and sys.path/PYTHONPATH · Typing in pytest · CI Pipelines · Flaky tests · Examples and customization tricks · Demo of Python failure reports with pytest · Basic patterns and examples · Parametrizing tests · Working with custom markers ·

New in version 2.0. If you use Python-2.5 or later you can invoke testing through the Python interpreter from the command line: python -m pytest [...] This is equivalent to invoking the command line script py.test [...] directly.

March 30, 2020 - About Manpages · FAQ · Service Information · / testing / python-pytest / pytest(1) links · language-indep link · package tracker · raw man page · table of contents · NAME · CALLING PYTEST THROUGH PYTHON -M PYTEST · POSSIBLE EXIT CODES · GETTING HELP ON VERSION, OPTION NAMES, ENVIRONMENT VARIABLES ·

$ pytest =========================== test session starts ============================ platform linux -- Python 3.x.y, pytest-9.x.y, pluggy-1.x.y rootdir: /home/sweet/project collected 1 item test_sample.py F [100%] ================================= FAILURES ================================= _______________________________ test_answer ________________________________ def test_answer(): > assert func(3) == 5 E assert 4 == 5 E + where 4 = func(3) test_sample.py:6: AssertionError ========================= short test summary info ========================== FAILED test_sample.py::test_answer - assert 4 == 5 ============================ 1 failed in 0.12s =============================

pytest import mechanisms and sys.path/PYTHONPATH · Import modes · prepend and append import modes scenarios · Invoking pytest versus python -m pytest · Examples and customization tricks · Demo of Python failure reports with pytest · Basic patterns and examples ·

January 26, 2018 - $ pytest test_analytics.py ========================== test session starts =========================== platform linux2 -- Python 2.7.11, pytest-2.9.1, py-1.4.31, pluggy-0.3.1 collected 1 items test_analytics.py F ================================ FAILURES ================================ ________________________________ test_sum ________________________________ def test_fastsum(): > assert analytics.fastsum([1, 2, 3]) == 7 E assert 6 == 7 E + where 6 = analytics.fastsum([1, 2, 3]) test_analytics.py:4: AssertionError ========================= 1 failed in 0.01 seconds ======================

Managing loading of plugins · Early loading plugins · Disabling plugins · Other ways of calling pytest · Calling pytest through python -m pytest · Calling pytest from Python code · Documentation overview · Previous: Get Started · Next: How to write and report assertions in tests ·

Pytest while the test is getting executed, will see the fixture name as input parameter. It then executes the fixture function and the returned value is stored to the input parameter, which can be used by the test. ... ============================ test session starts ================================ platform win32 -- Python 3.14.2, pytest-9.0.2, pluggy-1.6.0 -- C:\Users\mahes\AppData\Local\Programs\Python\Python314\python.exe cachedir: .pytest_cache rootdir: D:\Projects\python\myenv\automation collected 7 items / 5 deselected / 2 selected test_div_by_3_6.py::test_divisible_by_3 PASSED [ 50%] t

March 11, 2022 - Python projects with good tests written using pytest.

SYNOPSIS usage: pytest [OPTIONS] [testfile [testpattern]] examples: pytest path/to/mytests.py pytest path/to/mytests.py TheseTests pytest path/to/mytests.py TheseTests.test_thisone pytest one (will run both test_thisone and test_thatone) pytest path/to/mytests.py -s not (will skip test_notthisone) pytest --coverage test_foo.py (only if logilab.devtools is available) options: -h, --help show this help message and exit -t TESTDIR directory where the tests will be found -d enable design-by-contract -v, --verbose Verbose output -i, --pdb Enable test failure inspection (conflicts with --coverage) -

December 12, 2023 - Invoking Pytest with python -m pytest is akin to running your test scripts through the Python interpreter as a module. This method has significant implications for your testing environment, particularly in how Python manages module resolution and path settings.

July 10, 2025 - pytest.raises Context Manager is a tool that checks if your code raises specific exceptions. If the specified exception is raised, that test passes, confirming that the expected error occurred.

This will invoke the Python debugger on every failure (or KeyboardInterrupt). Often you might only want to do this for the first failing test to understand a certain failure situation: pytest -x --pdb # drop to PDB on first failure, then end test session pytest --pdb --maxfail=3 # drop to PDB for first three failures