Python Project Metadata

maturin supports PEP 621, you can specify python package metadata in pyproject.toml. maturin merges metadata from Cargo.toml and pyproject.toml, pyproject.toml takes precedence over Cargo.toml.

Here is a pyproject.toml example from PEP 621 for reference purpose:

[project]
name = "spam"
version = "2020.0.0"
description = "Lovely Spam! Wonderful Spam!"
readme = "README.rst"
requires-python = ">=3.8"
license = {file = "LICENSE.txt"}
keywords = ["egg", "bacon", "sausage", "tomatoes", "Lobster Thermidor"]
authors = [
  {email = "hi@pradyunsg.me"},
  {name = "Tzu-Ping Chung"}
]
maintainers = [
  {name = "Brett Cannon", email = "brett@python.org"}
]
classifiers = [
  "Development Status :: 4 - Beta",
  "Programming Language :: Python"
]

dependencies = [
  "httpx",
  "gidgethub[httpx]>4.0.0",
  "django>2.1; os_name != 'nt'",
  "django>2.0; os_name == 'nt'"
]

[project.optional-dependencies]
test = [
  "pytest < 5.0.0",
  "pytest-cov[all]"
]

[project.urls]
homepage = "example.com"
documentation = "readthedocs.org"
repository = "github.com"
changelog = "github.com/me/spam/blob/master/CHANGELOG.md"

[project.scripts]
spam-cli = "spam:main_cli"

[project.gui-scripts]
spam-gui = "spam:main_gui"

[project.entry-points."spam.magical"]
tomatoes = "spam:main_tomatoes"

Dynamic metadata

Maturin has limited support for dynamic metadata in pyproject.toml.

When the [project] section is not present, maturin will populate metadata from Cargo.toml with the following fields:

name - From package.name in Cargo.toml
version - From package.version in Cargo.toml (converted from SemVer to PEP 440 format)
summary - From package.description in Cargo.toml
description - From the contents of the README file specified in Cargo.toml's package.readme
description_content_type - Set based on the README file extension (e.g. text/markdown for .md files)
keywords - From package.keywords in Cargo.toml, joined with commas
home_page - From package.homepage in Cargo.toml
author - From package.authors in Cargo.toml, joined with commas
author_email - From package.authors in Cargo.toml if it contains email addresses
license - From package.license in Cargo.toml
project_url - From various URLs in Cargo.toml (like repository, homepage, etc.)

When the [project] section is present, maturin will merge metadata from Cargo.toml and pyproject.toml, pyproject.toml takes precedence over Cargo.toml. Per specification, maturin is not allowed to populate fields that are not present in project.dynamic list when the [project] section is present. For example, to use the Rust crate version as the Python package version, you need to add version to the project.dynamic list:

[project]
name = "my-awesome-project"
dynamic = ["version"]

Add Python dependencies

To specify python dependencies, add a list dependencies in a [project] section in the pyproject.toml. This list is equivalent to install_requires in setuptools:

[project]
name = "my-project"
dependencies = ["flask~=1.1.0", "toml==0.10.0"]

Add console scripts

Pip allows adding so called console scripts, which are shell commands that execute some function in you program. You can add console scripts in a section [project.scripts]. The keys are the script names while the values are the path to the function in the format some.module.path:class.function, where the class part is optional. The function is called with no arguments. Example:

[project.scripts]
get_42 = "my_project:DummyClass.get_42"

Add trove classifiers

You can also specify trove classifiers under project.classifiers:

[project]
name = "my-project"
classifiers = ["Programming Language :: Python"]

Add SPDX license expressions

A practical string value for the license key has been purposefully left out by PEP 621 to allow for a future PEP to specify support for SPDX expressions.

To use SPDX license expressions, you can specify it in Cargo.toml instead:

[package]
name = "my-project"
license = "MIT OR Apache-2.0"

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