pytest module

Date: January 16th 2016
Last updated: January 16th 2016

pytest can run tests suites from unittest doctest and nose modules. For documentation see their webpage and pytest.pdf. Installation and setup is similar to nose.

# install latest pytest
pip install -U pytest

# print version of pytest
py.test --version
# Output:
#This is pytest version 2.8.5, imported from ...snipped...
#anaconda2/lib/python2.7/site-packages/pytest.pyc

# get help
py.test --help

Assuming the existing file structure from testing with nose:

Project
├── test
│   ├── __init__.py
│   ├── test_vowels_nose.py     # nose test script
│   └── test_vowels.py          # unittest test script
└── vowels
    ├── __init__.py
    ├── vowelsclass.py          # new vowels script
    └── vowels.py

Run existing test functions:

# run at Project directory with auto-discovery
py.test
# specify one file
py.test test/test_vowels.py
# stop after first failure
py.test -x
# stop after N=4 failures
py.test --maxfail=4
# verbosity
py.test -v
# quiet 
py.test -q

Debuggers:

# doctests
py.test --doctest-modules
# pdb
py.test -x --pdb # on first failure
py.test --maxfail=2 # go tp pdb for the first two failures

Output from a failed test (modified test_vowels.py to fail):

Output of a failed doctest: