An example repository to demonstrate Python support in Pants.
See pantsbuild.org for much more detailed documentation.
This is only one possible way of laying out your project with Pants. See pantsbuild.org/docs/source-roots#examples for some other example layouts.
You run Pants goals using the
./pants wrapper script, which will bootstrap the
configured version of Pants if necessary.
❓Running with Apple Silicon and/or MacOS? You will want to make changes to the
./pants- there is guidance in
pants.tomlfor those settings.
./pants --version to see the version of Pants configured for the repo (which you can also find
Pants commands are called goals. You can get a list of goals with
./pants help goals
Targets are a way of setting metadata for some part of your code, such as timeouts for tests and
entry points for binaries. Targets have types like
pex_binary. They are defined in
Pants goals can be invoked on targets or directly on source files (which is often more intuitive and convenient). In the latter case, Pants locates target metadata for the source files as needed.
Invoking goals on files is straightforward, e.g.,
./pants test helloworld/greet/greeting_test.py
You can use globs:
./pants lint helloworld/greet/*.py
But note that these will be expanded by your shell, so this is equivalent to having used
./pants lint helloworld/greet/__init__.py helloworld/greet/greeting.py helloworld/greet/greeting_test.py
If you want Pants itself to expand the globs (which is sometimes necessary), you must quote them in the shell:
./pants lint 'helloworld/greet/*.py'
You can run on all changed files:
./pants --changed-since=HEAD lint
You can run on all changed files, and any of their "dependees":
./pants --changed-since=HEAD --changed-dependees=transitive test
Targets are referenced on the command line using their address, of the form
./pants lint helloworld/greet:lib
You can glob over all targets in a directory with a single trailing
:, or over all targets in a directory
and all its subdirectories with a double trailing
./pants lint helloworld::
When you glob over files or targets, Pants knows to ignore ones that aren't relevant to the requested goal.
For example, if you run the
test goal over a set of files that includes non-test files, Pants will just ignore
those, rather than error. So you can safely do things like
./pants test ::
To run all tests.
Try these out in this repo!
./pants list :: # All targets. ./pants list 'helloworld/**/*.py' # Just targets containing Python code.
Run linters and formatters
./pants lint :: ./pants fmt helloworld/greet::
./pants check ::
./pants test :: # Run all tests in the repo. ./pants test --output=all :: # Run all tests in the repo and view pytest output even for tests that passed (you can set this permanently in pants.toml). ./pants test helloworld/translator:tests # Run all the tests in this target. ./pants test helloworld/translator/translator_test.py # Run just the tests in this file. ./pants test helloworld/translator/translator_test.py -- -k test_unknown_phrase # Run just this one test by passing through pytest args.
Create a PEX binary
./pants package helloworld/main.py
Run a binary directly
./pants run helloworld/main.py
Open a REPL
./pants repl helloworld/greet:lib # The REPL will have all relevant code and dependencies on its sys.path. ./pants repl --shell=ipython helloworld/greet:lib --no-pantsd # To use IPython, you must disable Pantsd for now.
Build a wheel / generate
This will build both a
.whl bdist and a
./pants package helloworld/translator:dist
Count lines of code
./pants count-loc '**/*'
Create virtualenv for IDE integration
./pants export ::