check-python-versions 0.9.0

Compare supported Python versions in setup.py vs tox.ini et al.

This is a tool for Python package maintainers who want to explicitly state which Python versions they support.

The problem: to properly support e.g. Python 2.7 and 3.4+ you have to run tests with these Pythons. This means

• you need a tox.ini with envlist = py27, py34, py35, py36, py37

• you need a .travis.yml with python: [ 2.7, 3.4, 3.5, 3.6, 3.7 ]

• if you support Windows, you need an appveyor.yml with %PYTHON% set to C:\Python2.7, C:\Python3.4, and so on

• if you’re building manylinux wheels you need to … you get the idea

• you have to tell the users which Python versions you support by specifying trove classifiers like “Programming Language :: Python :: 2.7”

• you probably also want to tell pip which versions you support by specifying python_requires=”>= 2.7, !=3.0.* …” because AFAIU PyPI classifiers are not fine-grained enough

Keeping all these lists consistent is a pain.

The solution: check-python-versions will compare these lists and warn you if they don’t match

$ check-python-versions ~/projects/*
/home/mg/projects/check-manifest:

setup.py says:              2.7, 3.4, 3.5, 3.6, 3.7, PyPy
- python_requires says:     2.7, 3.4, 3.5, 3.6, 3.7
tox.ini says:               2.7, 3.4, 3.5, 3.6, 3.7, PyPy, PyPy3
.travis.yml says:           2.7, 3.4, 3.5, 3.6, 3.7, PyPy, PyPy3
appveyor.yml says:          2.7, 3.4, 3.5, 3.6, 3.7


/home/mg/projects/dozer:

setup.py says:              2.7, 3.4, 3.5, 3.6, 3.7
tox.ini says:               2.7, 3.4, 3.5, 3.6, 3.7
.travis.yml says:           2.7, 3.4, 3.5, 3.6, 3.7
appveyor.yml says:          2.7, 3.4, 3.5, 3.6, 3.7


/home/mg/projects/eazysvn:

setup.py says:              2.7, 3.4, 3.5, 3.6, 3.7, PyPy
tox.ini says:               2.7, 3.4, 3.5, 3.6, 3.7, PyPy, PyPy3
.travis.yml says:           2.7, 3.4, 3.5, 3.6, 3.7, PyPy, PyPy3
appveyor.yml says:          2.7, 3.4, 3.5, 3.6, 3.7

...

all ok!

Installation

You need Python 3.6 or newer (f-strings!) to run check-python-versions. Install it with

python3 -m pip install check-python-versions

Usage

$ check-python-versions --help
usage: check-python-versions [-h] [--version] [--expect VERSIONS]
                             [--skip-non-packages]
                             [where [where ...]]

verify that supported Python versions are the same in setup.py, tox.ini,
.travis.yml and appveyor.yml

positional arguments:
  where                directory where a Python package with a setup.py and
                       other files is located

optional arguments:
  -h, --help           show this help message and exit
  --version            show program's version number and exit
  --expect VERSIONS    expect these versions to be supported, e.g. --expect
                       2.7,3.4-3.7
  --skip-non-packages  skip arguments that are not Python packages without
                       warning about them

If run without any arguments, check-python-versions will look for a setup.py in the current working directory.

Exit status is 0 if all Python packages had consistent version numbers (and, if –expect is specified, those numbers match your stated expectations).

If you specify multiple directories on the command line, then all packages that failed a check will be listed at the end of the run, separated with spaces, for easier copying and pasting onto shell command lines. This is helpful when, e.g. you want to run

check-python-versions ~/src/zopefoundation/*

to check all 380+ packages, and then want re-run the checks only on the failed ones, for a faster turnabout.

Files

setup.py is the only required file; if any of the others are missing, they’ll be ignored (and this will not considered a failure).

• setup.py: the classifiers argument passed to setup() is expected to have classifiers of the form:

  classifiers=[
      ...
      "Programming Language :: Python :: x.y",
      ...
  ],

  check-python-versions will attempt to parse the file and walk the AST to extract classifiers, but if that fails, it’ll execute python setup.py --classifiers and parse the output.

• setup.py: the python_requires argument passed to setup(), if present:

  python_requires=">=2.7, !=3.0.*, !=3.1.*",

  check-python-versions will attempt to parse the file and walk the AST to extract the python_requires value. It expects to find a string literal or a simple expression of the form "literal".join(["...", "..."]).

  Only >= and != constraints are currently supported.

• tox.ini: if present, it’s expected to have

  [tox]
  envlist = pyXY, ...

  Environment names like pyXY-ZZZ are also accepted; the suffix is ignored.

• .travis.yml: if present, it’s expected to have

  python:
    - X.Y
    - ...

  and/or

  matrix:
    include:
      - python: X.Y
        ...
      - ...

  and/or

  jobs:
    include:
      - python: X.Y
        ...
      - ...

• appveyor.yml: if present, it’s expected to have

  environment:
    matrix:
      - PYTHON: C:\\PythonX.Y
      - ...

  The environment variable name is assumed to be PYTHON or python. The values should be one of

  • X.Y

  • C:\\PythonX.Y (case-insensitive)

  • C:\\PythonX.Y-x64 (case-insensitive)

• .manylinux-install.sh: if present, it’s expected to contain a loop like

  for PYBIN in /opt/python/*/bin; do
      if [[ "${PYBIN}" == *"cp27"* ]] || \
         [[ "${PYBIN}" == *"cp34"* ]] || \
         [[ "${PYBIN}" == *"cp35"* ]] || \
         [[ "${PYBIN}" == *"cp36"* ]] || \
         [[ "${PYBIN}" == *"cp37"* ]]; then
          "${PYBIN}/pip" install -e /io/
          "${PYBIN}/pip" wheel /io/ -w wheelhouse/
             rm -rf /io/build /io/*.egg-info
      fi
  done

  check-python-versions will look for $PYBIN tests of the form

  [[ "${PYBIN}" == *"cpXY"* ]]

  where X and Y are arbitrary digits.

  These scripts are used in several zopefoundation repositories like zopefoundation/zope.interface. It’s the least standartized format.

Python versions

In addition to CPython X.Y, check-python-versions will recognize PyPy and PyPy3 in some of the files:

• setup.py may have a

  'Programming Language :: Python :: Implementation :: PyPy',

  classifier

• tox.ini may have pypy[-suffix] and pypy3[-suffix] environments

• .travis.yml may have pypy and pypy3 jobs

• appveyor.yml and .manylinux-install.sh do not usually have pypy tests, so check-python-versions cannot recognize them.

These extra Pythons are shown, but not compared for consistency.

In addition, python_requires in setup.py usually has a lower limit, but no upper limit. check-python-versions will assume this means support up to the current Python 3.x release (3.7 at the moment).