Tags

Wheels encode the Python interpreter, ABI, and platform that they support in their filenames using `platform compatibility tags`_. This module provides support for both parsing these tags as well as discovering what tags the running Python interpreter supports.

Usage

>>> from packaging.tags import Tag, sys_tags
>>> import sys
>>> looking_for = Tag("py{major}".format(major=sys.version_info.major), "none", "any")
>>> supported_tags = list(sys_tags())
>>> looking_for in supported_tags
True
>>> really_old = Tag("py1", "none", "any")
>>> wheels = {really_old, looking_for}
>>> best_wheel = None
>>> for supported_tag in supported_tags:
...     for wheel_tag in wheels:
...         if supported_tag == wheel_tag:
...             best_wheel = wheel_tag
...             break
>>> best_wheel == looking_for
True

Reference

packaging.tags.INTERPRETER_SHORT_NAMES

A dictionary mapping interpreter names to their abbreviation codes (e.g. "cpython" is "cp"). All interpreter names are lower-case.

class packaging.tags.Tag(interpreter, abi, platform)[source]

A representation of the tag triple for a wheel. Instances are considered immutable and thus are hashable. Equality checking is also supported.

Parameters:
  • interpreter (str) – The interpreter name, e.g. "py" (see INTERPRETER_SHORT_NAMES for mapping well-known interpreter names to their short names).
  • abi (str) – The ABI that a wheel supports, e.g. "cp37m".
  • platform (str) – The OS/platform the wheel supports, e.g. "win_amd64".
interpreter

The interpreter name.

abi

The supported ABI.

platform

The OS/platform.

packaging.tags.parse_tag(tag)[source]

Parses the provided tag into a set of Tag instances.

Returning a set is required due to the possibility that the tag is a compressed tag set, e.g. "py2.py3-none-any" which supports both Python 2 and Python 3.

Parameters:tag (str) – The tag to parse, e.g. "py3-none-any".
packaging.tags.sys_tags(*, warn=False)[source]

Yields the tags that the running interpreter supports.

The iterable is ordered so that the best-matching tag is first in the sequence. The exact preferential order to tags is interpreter-specific, but in general the tag importance is in the order of:

  1. Interpreter
  2. Platform
  3. ABI

This order is due to the fact that an ABI is inherently tied to the platform, but platform-specific code is not necessarily tied to the ABI. The interpreter is the most important tag as it dictates basic support for any wheel.

The function returns an iterable in order to allow for the possible short-circuiting of tag generation if the entire sequence is not necessary and tag calculation happens to be expensive.

Parameters:warn (bool) – Whether warnings should be logged. Defaults to False.
packaging.tags.interpreter_name()[source]

Returns the running interpreter’s name.

This typically acts as the prefix to the interpreter tag.

packaging.tags.interpreter_version(*, warn=False)[source]

Returns the running interpreter’s version.

This typically acts as the suffix to the interpreter tag.

packaging.tags.mac_platforms(version=None, arch=None)[source]

Yields the platform tags for macOS.

Parameters:
  • version (tuple) – A two-item tuple presenting the version of macOS. Defaults to the current system’s version.
  • arch (str) – The CPU architecture. Defaults to the architecture of the current system, e.g. "x86_64".

Note

Equivalent support for the other major platforms is purposefully not provided:

  • On Windows, platform compatibility is statically specified
  • On Linux, code must be run on the system itself to determine compatibility
packaging.tags.compatible_tags(python_version=None, interpreter=None, platforms=None)[source]

Yields the tags for an interpreter compatible with the Python version specified by python_version.

The specific tags generated are:

  • py*-none-<platform>
  • <interpreter>-none-any if interpreter is provided
  • py*-none-any
Parameters:
  • python_version (Sequence) – A one- or two-item sequence representing the compatible version of Python. Defaults to sys.version_info[:2].
  • interpreter (str) – The name of the interpreter (if known), e.g. "cp38". Defaults to the current interpreter.
  • platforms (Iterable) – Iterable of compatible platforms. Defaults to the platforms compatible with the current system.
packaging.tags.cpython_tags(python_version=None, abis=None, platforms=None, *, warn=False)[source]

Yields the tags for the CPython interpreter.

The specific tags generated are:

  • cp<python_version>-<abi>-<platform>
  • cp<python_version>-abi3-<platform>
  • cp<python_version>-none-<platform>
  • cp<older version>-abi3-<platform> where “older version” is all older minor versions down to Python 3.2 (when abi3 was introduced)

If python_version only provides a major-only version then only user-provided ABIs via abis and the none ABI will be used.

Parameters:
  • python_version (Sequence) – A one- or two-item sequence representing the targetted Python version. Defaults to sys.version_info[:2].
  • abis (Iterable) – Iterable of compatible ABIs. Defaults to the ABIs compatible with the current system.
  • platforms (Iterable) – Iterable of compatible platforms. Defaults to the platforms compatible with the current system.
  • warn (bool) – Whether warnings should be logged. Defaults to False.
packaging.tags.generic_tags(interpreter=None, abis=None, platforms=None, *, warn=False)[source]

Yields the tags for an interpreter which requires no specialization.

This function should be used if one of the other interpreter-specific functions provided by this module is not appropriate (i.e. not calculating tags for a CPython interpreter).

The specific tags generated are:

  • <interpreter>-<abi>-<platform>

The "none" ABI will be added if it was not explicitly provided.

Parameters:
  • interpreter (str) – The name of the interpreter. Defaults to being calculated.
  • abis (Iterable) – Iterable of compatible ABIs. Defaults to the ABIs compatible with the current system.
  • platforms (Iterable) – Iterable of compatible platforms. Defaults to the platforms compatible with the current system.
  • warn (bool) – Whether warnings should be logged. Defaults to False.