Options for Pants's Python support.

Config section: [python-setup]

Basic options


Advanced options


--python-setup-interpreter-constraints="[<requirement>, <requirement>, ...]"

The Python interpreters your codebase is compatible with.

Specify with requirement syntax, e.g. 'CPython>=2.7,<3' (A CPython interpreter with version >=2.7 AND version <3) or 'PyPy' (A pypy interpreter of any version). Multiple constraint strings will be ORed together.

These constraints are used as the default value for the interpreter_constraints field of Python targets.


default: None

When resolving third-party requirements, use this constraints file to determine which versions to use.

See for more information on the format of constraint files and how constraints are applied in Pex and pip.

Mutually exclusive with --requirement-constraints-target.


default: None

When resolving third-party requirements, use this _python_constraints target to determine which versions to use.

This is primarily intended for macros (for now). Normally, use --requirement-constraints instead with a constraints file.

See for more information on the format of constraints and how constraints are applied in Pex and pip.


one of: never, nondeployables, always, True, False
default: True

If enabled, when resolving requirements, Pants will first resolve your entire constraints file as a single global resolve. Then, if the code uses a subset of your constraints file, Pants will extract the relevant requirements from that global resolve so that only what's actually needed gets used. If disabled, Pants will not use a global resolve and will resolve each subset of your requirements independently.

Usually this option should be enabled because it can result in far fewer resolves.

Requires [python-setup].requirement_constraints to be set.


--python-setup-interpreter-search-paths="[<binary-paths>, <binary-paths>, ...]"

A list of paths to search for Python interpreters that match your project's interpreter constraints. You can specify absolute paths to interpreter binaries and/or to directories containing interpreter binaries. The order of entries does not matter. The following special strings are supported:

  • "<PATH>", the contents of the PATH env var
  • "<PYENV>", all Python versions under $(pyenv root)/versions
  • "<PYENV_LOCAL>", the Pyenv interpreter with the version in BUILD_ROOT/.python-version
  • "<PEXRC>", paths in the PEX_PYTHON_PATH variable in /etc/pexrc or ~/.pexrc


default: manylinux2014

Whether to allow resolution of manylinux wheels when resolving requirements for foreign linux platforms. The value should be a manylinux platform upper bound, e.g.: 'manylinux2010', or else the string 'no' to disallow.


default: 4

The maximum number of concurrent jobs to build wheels with.

Because Pants can run multiple subprocesses in parallel, the maximum total parallelism will be --process-execution-{local,remote}-parallelism x --python-setup-resolver-jobs.

Setting this option higher may result in better parallelism, but, if set too high, may result in starvation and Out of Memory errors.

Defaults to half the cores on your machine.

Deprecated options


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