Configuring setup() using setup.cfg files

Note

New in 30.3.0 (8 Dec 2016).

Important

If compatibility with legacy builds (i.e. those not using the PEP 517 build API) is desired, a setup.py file containing a setup() function call is still required even if your configuration resides in setup.cfg.

Setuptools allows using configuration files (usually setup.cfg) to define a package’s metadata and other options that are normally supplied to the setup() function (declarative config).

This approach not only allows automation scenarios but also reduces boilerplate code in some cases.

[metadata]
name = my_package
version = attr: src.VERSION
description = My package description
long_description = file: README.rst, CHANGELOG.rst, LICENSE.rst
keywords = one, two
license = BSD 3-Clause License
classifiers =
    Framework :: Django
    License :: OSI Approved :: BSD License
    Programming Language :: Python :: 3
    Programming Language :: Python :: 3.5

[options]
zip_safe = False
include_package_data = True
packages = find:
scripts =
    bin/first.py
    bin/second.py
install_requires =
    requests
    importlib; python_version == "2.6"

[options.package_data]
* = *.txt, *.rst
hello = *.msg

[options.entry_points]
console_scripts =
    executable-name = package.module:function

[options.extras_require]
pdf = ReportLab>=1.2; RXP
rest = docutils>=0.3; pack ==1.1, ==1.3

[options.packages.find]
exclude =
    src.subpackage1
    src.subpackage2

[options.data_files]
/etc/my_package =
    site.d/00_default.conf
    host.d/00_default.conf
data = data/img/logo.png, data/svg/icon.svg

Metadata and options are set in the config sections of the same name.

  • Keys are the same as the keyword arguments one provides to the setup() function.

  • Complex values can be written comma-separated or placed one per line in dangling config values. The following are equivalent:

    [metadata]
    keywords = one, two
    
    [metadata]
    keywords =
        one
        two
    
  • In some cases, complex values can be provided in dedicated subsections for clarity.

  • Some keys allow file:, attr:, find:, and find_namespace: directives in order to cover common usecases.

  • Unknown keys are ignored.

Using a src/ layout

One commonly used package configuration has all the module source code in a subdirectory (often called the src/ layout), like this:

├── src
│   └── mypackage
│       ├── __init__.py
│       └── mod1.py
├── setup.py
└── setup.cfg

You can set up your setup.cfg to automatically find all your packages in the subdirectory like this:

# This example contains just the necessary options for a src-layout, set up
# the rest of the file as described above.

[options]
package_dir=
    =src
packages=find:

[options.packages.find]
where=src

Specifying values

Some values are treated as simple strings, some allow more logic.

Type names used below:

  • str - simple string

  • list-comma - dangling list or string of comma-separated values

  • list-semi - dangling list or string of semicolon-separated values

  • bool - True is 1, yes, true

  • dict - list-comma where keys are separated from values by =

  • section - values are read from a dedicated (sub)section

Special directives:

  • attr: - Value is read from a module attribute. attr: supports callables and iterables; unsupported types are cast using str().

    In order to support the common case of a literal value assigned to a variable in a module containing (directly or indirectly) third-party imports, attr: first tries to read the value from the module by examining the module’s AST. If that fails, attr: falls back to importing the module.

  • file: - Value is read from a list of files and then concatenated

    Note

    The file: directive is sandboxed and won’t reach anything outside the directory containing setup.py.

Metadata

Note

The aliases given below are supported for compatibility reasons, but their use is not advised.

Key

Aliases

Type

Minimum Version

Notes

name

str

version

attr:, file:, str

39.2.0

1

url

home-page

str

download_url

download-url

str

project_urls

dict

38.3.0

author

str

author_email

author-email

str

maintainer

str

maintainer_email

maintainer-email

str

classifiers

classifier

file:, list-comma

license

str

license_files

license_file

list-comma

42.0.0

description

summary

file:, str

long_description

long-description

file:, str

long_description_content_type

str

38.6.0

keywords

list-comma

platforms

platform

list-comma

provides

list-comma

requires

list-comma

obsoletes

list-comma

Notes:

1

The version file attribute has only been supported since 39.2.0.

A version loaded using the file: directive must comply with PEP 440. It is easy to accidentally put something other than a valid version string in such a file, so validation is stricter in this case.

Options

Key

Type

Minimum Version

Notes

zip_safe

bool

setup_requires

list-semi

install_requires

list-semi

extras_require

section

3

python_requires

str

entry_points

file:, section

51.0.0

use_2to3

bool

use_2to3_fixers

list-comma

use_2to3_exclude_fixers

list-comma

convert_2to3_doctests

list-comma

scripts

list-comma

eager_resources

list-comma

dependency_links

list-comma

tests_require

list-semi

include_package_data

bool

packages

find:, find_namespace:, list-comma

4

package_dir

dict

package_data

section

2

exclude_package_data

section

namespace_packages

list-comma

py_modules

list-comma

data_files

dict

40.6.0

Notes:

2

In the package_data section, a key named with a single asterisk (*) refers to all packages, in lieu of the empty string used in setup.py.

3

In the extras_require section, values are parsed as list-semi. This implies that in order to include markers, they must be dangling:

[options.extras_require]
rest = docutils>=0.3; pack ==1.1, ==1.3
pdf =
  ReportLab>=1.2
  RXP
  importlib-metadata; python_version < "3.8"
4

The find: and find_namespace: directive can be further configured in a dedicated subsection options.packages.find. This subsection accepts the same keys as the setuptools.find_packages and the setuptools.find_namespace_packages function: where, include, and exclude.

The find_namespace: directive is supported since Python >=3.3.

Compatibility with other tools

Historically, several tools explored declarative package configuration in parallel. And several of them chose to place the packaging configuration within the project’s setup.cfg file. One of the first was distutils2, which development has stopped in 2013. Other include pbr which is still under active development or d2to1, which was a plug-in that backports declarative configuration to distutils, but has had no release since Oct. 2015. As a way to harmonize packaging tools, setuptools, having held the position of de facto standard, has gradually integrated those features as part of its core features.

Still this has lead to some confusion and feature incompatibilities:

  • some tools support features others don’t;

  • some have similar features but the declarative syntax differs;

The table below tries to summarize the differences. But, please, refer to each tool documentation for up-to-date information.

feature

setuptools

distutils2

d2to1

pbr

[metadata] description-file

S

Y

Y

Y

[files]

S

Y

Y

Y

entry_points

Y

Y

Y

S

[backwards_compat]

N

Y

Y

Y

Y: supported, N: unsupported, S: syntax differs (see above example).

Also note that some features were only recently added to setuptools. Please refer to the previous sections to find out when.