Augment/replace setup.py with pyproject.toml

Related: Minimal setup.py

pip ≥ 10 can use pyproject.toml instead of (or more commonly, along with) setup.py, for simpler syntax. pyproject.toml is particularly useful for f2py programs where Numpy must be installed before running setup.py install.

flit uses pyproject.toml for simpler PyPi uploads, and can also install programs (as alternative to pip), even without setup.py. End users can simply flit installfrom Github, without needing to git clone or use PyPi (unless they want to). flit and pyproject.toml lower Python program distribution difficulty for developers who don’t want to mess with PyPi, but also make it easier for those who do use PyPi.

Example: f2py

This example uses pyproject.toml to augment setup.py by first installing Numpy (setuptools.setup(setup_requires=['numpy']) is not recommended):

pyproject.toml:

[build-system]
requires = ["setuptools", "wheel","numpy"]

setup.py is constructed as usual, and when doing pip install -e . or pip install mypkg, Numpy will be installed first so that f2py or other Numpy-based extension modules can be built. A real-life example of this is in Lowtran

Example: pyproject.toml instead of setup.py

  1. author: flit publish to PyPi
  2. end-user: python -m pip install yourprogram this uses pyproject.toml alone to install.

Users can also install from local or remote Git repos:

  • end-user: flit installfrom https://github.com/username/yourprogram/archive/master.zip this downloads and installs the latest Git commit to master branch (or other branch or release version they choose)
  • developer-user: git clone your repo and install in develop mode by flit install -s. This puts a symbolic link to your local Git directory (where you git clone’d).

This standard was defined in

Minimal pyproject.toml

  1. assuming your package is named myprogram, have a directory structure like

    pyproject.toml
myprogram/
   __init__.py

  2. ensure your __init__.py starts with a one-line description and version. You must increment this version for each PyPi upload (or use bumpversion).

    """My program is 2x faster and 1/3 the size of Hello World."""
__version__ = '0.1.0'

  3. pyproject.toml contains something like:

    [build-system]
requires = ["flit"]
build-backend = "flit.buildapi"

[tool.flit.metadata]
module = "myprogram"
author = "Author Name"
author-email = "username@users.noreply.github.com"
home-page = "https://github.com/username/reponame"

requires=['numpy','matplotlib (>=2.1)']
requires-python='>=3.5'

description-file='README.rst'
classifiers=[
'Development Status :: 4 - Beta',
'Programming Language :: Python']

PyPi upload

  1. Sign up for PyPi account. It may take several hours to get the confirmation email.

  2. create ~/.pypirc with the content

    [pypi]
username=pypiusername

    Note that I did NOT save my password for security.

  3. In your Python package directory that you want to upload

    flit upload

Now your package is live to the world on PyPi. Anyone can install it via

python -m pip install myprogram

Notes

  • Obtain flit via

    python -m pip install flit

  • description-file must be .rst or .md format.

  • These old methods are superseded by the methods above.

    • python setup.py install python -m pip install . → flit install
    • python setup.py develop python -m pip install -e . → flit install -s
    • python setup.py sdist bdist_wheel upload → flit upload

  • flit reference

  • f2py needs setup.py invoking numpy.distutils and python -m pip install -e .

  • Python-only project should use flit