python_test
A single Python test file, written in either Pytest style or unittest style.
All test util code, including conftest.py, should go into a dedicated python_source target and then be included in the dependencies field. (You can use the python_test_utils target to generate these python_source targets.)
See https://www.pantsbuild.org/v2.16/docs/python-test-goal
Backend: pants.backend.python
source
strA single file that belongs to this target.
Path is relative to the BUILD file's directory, e.g. source='example.ext'.
batch_compatibility_tag
str | NoneNoneAn arbitrary value used to mark the test files belonging to this target as valid for batched execution.
It's sometimes safe to run multiple python_tests within a single pytest process, and doing so can give significant wins by allowing reuse of expensive test setup / teardown logic. To opt into this behavior, set this field to an arbitrary non-empty string on all the python_test targets that are safe/compatible to run in the same process.
If this field is left unset on a target, the target is assumed to be incompatible with all others and will run in a dedicated pytest process.
If this field is set on a target, and its value is different from the value on some other python_test, then the two targets are explicitly incompatible and are guaranteed to not run in the same pytest process.
If this field is set on a target, and its value is the same as the value on some other python_test, then the two targets are explicitly compatible and may run in the same pytest process. Compatible tests may not end up in the same pytest batch if:
* There are "too many" compatible tests in a partition, as determined by the `[test].batch_size` config parameter, or
* Compatible tests have some incompatibility in Pants metadata (i.e. different `resolve`s or `extra_env_vars`).
When tests with the same batch_compatibility_tag have incompatibilities in some other Pants metadata, they will be automatically split into separate batches. This way you can set a high-level batch_compatibility_tag using __defaults__ and then have tests continue to work as you tweak BUILD metadata on specific targets.
dependencies
Iterable[str] | NoneNoneAddresses to other targets that this target depends on, e.g. ['helloworld/subdir:lib', 'helloworld/main.py:lib', '3rdparty:reqs#django'].
This augments any dependencies inferred by Pants, such as by analyzing your imports. Use pants dependencies or pants peek on this target to get the final result.
See https://www.pantsbuild.org/v2.16/docs/targets for more about how addresses are formed, including for generated targets. You can also run pants list :: to find all addresses in your project, or pants list dir to find all addresses defined in that directory.
If the target is in the same BUILD file, you can leave off the BUILD file path, e.g. :tgt instead of helloworld/subdir:tgt. For generated first-party addresses, use ./ for the file path, e.g. ./main.py:tgt; for all other generated targets, use :tgt#generated_name.
You may exclude dependencies by prefixing with !, e.g. ['!helloworld/subdir:lib', '!./sibling.txt']. Ignores are intended for false positives with dependency inference; otherwise, simply leave off the dependency from the BUILD file.
description
str | NoneNoneA human-readable description of the target.
Use pants list --documented :: to see all targets with descriptions.
environment
str | None'__local__'Specify which environment target to consume environment-sensitive options from.
Once environments are defined in [environments-preview].names, you can specify the environment for this target by its name. Any fields that are defined in that environment will override the values from options set by pants.toml, command line values, or environment variables.
You can specify multiple valid environments by using parametrize. If __local__ is specified, Pants will fall back to the local_environment defined for the current platform, or no environment if no such environment exists.
extra_env_vars
Iterable[str] | NoneNoneAdditional environment variables to include in test processes.
Entries are strings in the form ENV_VAR=value to use explicitly; or just ENV_VAR to copy the value of a variable in Pants's own environment.
This will be merged with and override values from [test].extra_env_vars.
interpreter_constraints
Iterable[str] | NoneNoneThe Python interpreters this code is compatible with.
Each element should be written in pip-style format, e.g. CPython==2.7.* or CPython>=3.6,<4. You can leave off CPython as a shorthand, e.g. >=2.7 will be expanded to CPython>=2.7.
Specify more than one element to OR the constraints, e.g. ['PyPy==3.7.*', 'CPython==3.7.*'] means either PyPy 3.7 or CPython 3.7.
If the field is not set, it will default to the option [python].interpreter_constraints.
See https://www.pantsbuild.org/v2.16/docs/python-interpreter-compatibility for how these interpreter constraints are merged with the constraints of dependencies.
resolve
str | NoneNoneThe resolve from [python].resolves to use.
If not defined, will default to [python].default_resolve.
All dependencies must share the same value for their resolve field.
run_goal_use_sandbox
bool | NoneNoneWhether to use a sandbox when running this target. Defaults to [python].run_goal_use_sandbox.
If true, runs of this target with the run goal will copy the needed first-party sources into a temporary sandbox and run from there.
If false, runs of this target with the run goal will use the in-repo sources directly.
The former mode is more hermetic, and is closer to building and running the source as it were packaged in a pex_binary. Additionally, it may be necessary if your sources depend transitively on "generated" files which will be materialized in the sandbox in a source root, but are not in-repo.
The latter mode is similar to creating, activating, and using a virtual environment when running your files. It may also be necessary if the source being run writes files into the repo and computes their location relative to the executed files. Django's makemigrations command is an example of such a process.
runtime_package_dependencies
Iterable[str] | NoneNoneAddresses to targets that can be built with the pants package goal and whose resulting artifacts should be included in the test run.
Pants will build the artifacts as if you had run pants package. It will include the results in your test's chroot, using the same name they would normally have, but without the --distdir prefix (e.g. dist/).
You can include anything that can be built by pants package, e.g. a pex_binary, python_awslambda, or an archive.
skip_add_trailing_comma
boolFalsepants.backend.experimental.python.lint.add_trailing_commaIf true, don't run add-trailing-comma on this target's code.
skip_autoflake
boolFalsepants.backend.python.lint.autoflakeIf true, don't run Autoflake on this target's code.
skip_bandit
boolFalsepants.backend.python.lint.banditIf true, don't run Bandit on this target's code.
skip_black
boolFalsepants.backend.python.lint.blackIf true, don't run Black on this target's code.
skip_docformatter
boolFalsepants.backend.python.lint.docformatterIf true, don't run Docformatter on this target's code.
skip_flake8
boolFalsepants.backend.python.lint.flake8If true, don't run Flake8 on this target's code.
skip_isort
boolFalsepants.backend.python.lint.isortIf true, don't run isort on this target's code.
skip_mypy
boolFalsepants.backend.python.typecheck.mypyIf true, don't run MyPy on this target's code.
skip_pydocstyle
boolFalsepants.backend.python.lint.pydocstyleIf true, don't run pydocstyle on this target's code.
skip_pylint
boolFalsepants.backend.python.lint.pylintIf true, don't run Pylint on this target's code.
skip_pyupgrade
boolFalsepants.backend.python.lint.pyupgradeIf true, don't run pyupgrade on this target's code.
skip_ruff
boolFalsepants.backend.experimental.python.lint.ruffIf true, don't run ruff on this target's code.
skip_tests
boolFalseIf true, don't run this target's tests.
skip_yapf
boolFalsepants.backend.python.lint.yapfIf true, don't run yapf on this target's code.
stevedore_namespaces
Iterable[str] | NoneNonepants.backend.experimental.python.framework.stevedoreList the stevedore namespaces required by this target.
Code for all entry_points on python_distribution targets with these namespaces will be added as dependencies so that they are available on PYTHONPATH during tests. Note that this is only a subset of the python_distributions dependencies, so the entry_points only need to be defined on one python_distribution even if the test only needs some of the entry_points namespaces on it.
Plus, an entry_points.txt file will be generated in the sandbox so that each of the python_distributions appear to be "installed". The entry_points.txt file will only include the namespaces requested on this field. Without this, stevedore would not be able to look up plugins in the setuptools entry_points metadata.
NOTE: Each python_distribution must opt-in to being included in this repo-wide inference by tagging the namespaces with stevedore_namespace("my.stevedore.extension").
The stevedore namespace format (my.stevedore.extension) is similar to a python namespace.
tags
Iterable[str] | NoneNoneArbitrary strings to describe a target.
For example, you may tag some test targets with 'integration_test' so that you could run pants --tag='integration_test' test :: to only run on targets with that tag.
timeout
int | NoneNoneA timeout (in seconds) used by each test file belonging to this target.
If unset, will default to [test].timeout_default; if that option is also unset, then the test will never time out. Will never exceed [test].timeout_maximum. Only applies if the option --test-timeouts is set to true (the default).
xdist_concurrency
int | NoneNoneMaximum number of CPUs to allocate to run each test file belonging to this target.
Tests are spread across multiple CPUs using pytest-xdist (https://pytest-xdist.readthedocs.io/en/latest/index.html). Use of pytest-xdist must be enabled using the [pytest].xdist_enabled option for this field to have an effect.
If pytest-xdist is enabled and this field is unset, Pants will attempt to derive the concurrency for test sources by counting the number of tests in each file.
Set this field to 0 to explicitly disable use of pytest-xdist for a target.