Building a Python Project
What This Guide Covers
Python builds are not available on the OSX environment.
Choosing Python versions to test against
Travis CI supports Python versions 2.6, 2.7, 3.2, 3.3, 3.4, 3.5, 3.6 as well as recent development versions.
language: python python: - "2.6" - "2.7" - "3.2" - "3.3" - "3.4" - "3.5" - "3.5-dev" # 3.5 development branch - "3.6" - "3.6-dev" # 3.6 development branch - "3.7-dev" # 3.7 development branch - "nightly" # currently points to 3.7-dev # command to install dependencies install: "pip install -r requirements.txt" # command to run tests script: pytest
As time goes, new releases come out and we provision more Python versions and/or implementations, aliases like
3.2 will float and point to different exact versions, patch levels and so on.
For precise versions pre-installed on the VM, please consult “Build system information” in the build log.
Travis CI Uses Isolated virtualenvs
CI Environment uses separate virtualenv instances for each Python version. System Python is not used and should not be relied on. If you need to install Python packages, do it via pip and not apt.
If you decide to use apt anyway, note that Python system packages only include Python 2.7 libraries on Ubuntu 12.04 LTS. This means that the packages installed from the repositories are not available in other virtualenvs even if you use the –system-site-packages option.
Travis CI supports PyPy and PyPy3.
To test your project against PyPy, add “pypy” or “pypy3” to the list of Pythons in your
language: python python: - "2.6" - "2.7" - "3.2" - "3.3" - "3.4" # PyPy versions - "pypy" - "pypy" # PyPy2 2.5.0 - "pypy3" # Pypy3 2.4.0 - "pypy-5.3.1" # command to install dependencies install: - pip install . - pip install -r requirements.txt # command to run tests script: pytest
Default Python Version
If you leave the
python key out of your
.travis.yml, Travis CI will use Python 2.7.
Specifying Test Script
Python projects need to provide the
script key in their
specify what command to run tests with.
For example, if your project uses pytest:
# command to run tests script: pytest # or py.test for Python versions 3.5 and below
if it uses
make test instead:
script: make test
If you do not provide a
script key in a Python project, Travis CI prints a
message and fails the build.
By default Travis CI uses
pip to manage python dependencies. If you have a
requirements.txt file, Travis CI runs
pip install -r requirements.txt
install phase of the build.
Note: If you’re running in the container-based infrastructure without access to
sudo you need to install dependencies in the home directory instead:
install: pip install --user -r requirements.txt
Custom Dependency Management
To override the default
pip dependency management, alter the
step as described in general build
Travis CI installs the following packages by default in each virtualenv:
Testing Against Multiple Versions of Dependencies (e.g. Django or Flask)
If you need to test against multiple versions of, say, Django, you can instruct Travis CI to do multiple runs with different sets or values of environment variables. Use env key in your .travis.yml file, for example:
env: - DJANGO_VERSION=1.7.8 - DJANGO_VERSION=1.8.2
and then use ENV variable values in your dependencies installation scripts, test cases or test script parameter values. Here we use DB variable value to instruct pip to install an exact version:
install: - pip install -q Django==$DJANGO_VERSION - python setup.py -q install
Nightly build support
Travis CI supports a special version name
nightly, which points to
a recent development version of CPython build.
It also has the packages above pre-installed.
For a limited number of Python development releases, on-demand installation is available.
Currently, these are:
3.5-dev (built nightly),
For Python projects,
python can be given as arrays
to construct a build matrix.