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Version: 2.21

python_requirement

A Python requirement installable by pip.

This target is useful when you want to declare Python requirements inline in a BUILD file. If you have a requirements.txt file already, you can instead use the target generator python_requirements to convert each requirement into a python_requirement target automatically. For Poetry, use poetry_requirements.

See https://www.pantsbuild.org/2.21/docs/python/overview/third-party-dependencies.

Backend: pants.backend.python

requirements​

Iterable[str]
required

A pip-style requirement string, e.g. ["Django==3.2.8"].

You can specify multiple requirements for the same project in order to use environment markers, such as ["foo>=1.2,<1.3 ; python_version>'3.6'", "foo==0.9 ; python_version<'3'"].

If the requirement depends on some other requirement to work, such as needing setuptools to be built, use the dependencies field instead.

dependencies​

Iterable[str] | None
default: None

Addresses 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/2.21/docs/using-pants/key-concepts/targets-and-build-files 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 | None
default: None

A human-readable description of the target.

Use pants list --documented :: to see all targets with descriptions.

entry_point​

str | None
default: None

Set the entry point, i.e. what gets run when executing ./my_app.pex, to a module.

You can specify a full module like 'path.to.module' and 'path.to.module:func', or use a shorthand to specify a file name, using the same syntax as the sources field:

  1. 'app.py', Pants will convert into the module path.to.app;
  2. 'app.py:func', Pants will convert into path.to.app:func.

You may only set one of: this field, or the script field, or the executable field. Leave off all three fields to have no entry point.

modules​

Iterable[str] | None
default: None

The modules this requirement provides (used for dependency inference).

For example, the requirement setuptools provides ["setuptools", "pkg_resources", "easy_install"].

Usually you can leave this field off. If unspecified, Pants will first look at the default module mapping (https://github.com/pantsbuild/pants/blob/release_2.21.2rc2/src/python/pants/backend/python/dependency_inference/default_module_mapping.py), and then will default to the normalized project name. For example, the requirement Django would default to the module django.

Mutually exclusive with the type_stub_modules field.

resolve​

str | None
default: None

The resolve from [python].resolves that this requirement is included in.

If not defined, will default to [python].default_resolve.

When generating a lockfile for a particular resolve via the generate-lockfiles goal, it will include all requirements that are declared with that resolve. First-party targets like python_source and pex_binary then declare which resolve they use via their resolve field; so, for your first-party code to use a particular python_requirement target, that requirement must be included in the resolve used by that code.

tags​

Iterable[str] | None
default: None

Arbitrary 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.

type_stub_modules​

Iterable[str] | None
default: None

The modules this requirement provides if the requirement is a type stub (used for dependency inference).

For example, the requirement types-requests provides ["requests"].

Usually you can leave this field off. If unspecified, Pants will first look at the default module mapping (https://github.com/pantsbuild/pants/blob/release_2.21.2rc2/src/python/pants/backend/python/dependency_inference/default_module_mapping.py). If not found and the requirement name starts with types- or stubs-, or ends with -types or -stubs, will default to that requirement name without the prefix/suffix. For example, types-requests would default to requests. Otherwise, will be treated like a normal requirement (see the modules field).

Mutually exclusive with the modules field.