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.
py.test --version # shows where pytest was imported from
py.test --funcargs # show available builtin function arguments
py.test -h | --help # show help on command line and config file options
To stop the testing process after the first (N) failures:
py.test -x # stop after first failure
py.test -maxfail=2 # stop after two failures
Several test run options:
py.test test_mod.py # run tests in module
py.test somepath # run all tests below path
py.test -k string # only run tests whose names contain a string
Import ‘pkg’ and use its filesystem location to find and run tests:
py.test --pyargs pkg # run all tests found below directory of pypkg
Examples for modifying traceback printing:
py.test --showlocals # show local variables in tracebacks
py.test -l # show local variables (shortcut)
py.test --tb=long # the default informative traceback formatting
py.test --tb=native # the Python standard library formatting
py.test --tb=short # a shorter traceback format
py.test --tb=line # only one line per failure
Python comes with a builtin Python debugger called PDB. py.test allows to drop into the PDB prompt via a command line option:
py.test --pdb
This will invoke the Python debugger on every failure. Often you might only want to do this for the first failing test to understand a certain failure situation:
py.test -x --pdb # drop to PDB on first failure, then end test session
py.test --pdb --maxfail=3 # drop to PDB for the first three failures
If you want to set a breakpoint and enter the pdb.set_trace() you can use a helper:
import pytest
def test_function():
...
pytest.set_trace() # invoke PDB debugger and tracing
In previous versions you could only enter PDB tracing if you disable capturing on the command line via py.test -s.
To create result files which can be read by Hudson or other Continuous integration servers, use this invocation:
py.test --junitxml=path
to create an XML file at path.
To create plain-text machine-readable result files you can issue:
py.test --resultlog=path
and look at the content at the path location. Such files are used e.g. by the PyPy-test web page to show test results over several revisions.
Creating a URL for each test failure:
py.test --pastebin=failed
This will submit test run information to a remote Paste service and provide a URL for each failure. You may select tests as usual or add for example -x if you only want to send one particular failure.
Creating a URL for a whole test session log:
py.test --pastebin=all
Currently only pasting to the http://paste.pocoo.org service is implemented.
New in version 2.0.
You can invoke py.test from Python code directly:
pytest.main()
this acts as if you would call “py.test” from the command line. It will not raise SystemExit but return the exitcode instead. You can pass in options and arguments:
pytest.main(['x', 'mytestdir'])
or pass in a string:
pytest.main("-x mytestdir")
You can specify additional plugins to pytest.main:
# content of myinvoke.py
import pytest
class MyPlugin:
def pytest_addoption(self, parser):
raise pytest.UsageError("hi from our plugin")
pytest.main(plugins=[MyPlugin()])
Running it will exit quickly:
$ python myinvoke.py
ERROR: hi from our plugin