Configuring setuptools 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: my_package.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
    Programming Language :: Python :: 3

[options]
zip_safe = False
include_package_data = True
packages = find:
install_requires =
    requests
    importlib-metadata; python_version<"3.8"

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

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

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

[options.packages.find]
exclude =
    examples*
    tools*
    docs*
    my_package.tests*

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 configuration has all the Python 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, using package_dir, 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

In this example, the value for the package_dir configuration (i.e. =src) is parsed as {"": "src"}. The "" key has a special meaning in this context, and indicates that all the packages are contained inside the given directory. Also note that the value for [options.packages.find] where matches the value associated with "" in the package_dir dictionary.

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 each entry corresponds to a key/value pair, with keys separated from values by =. If an entry starts with =, the key is assumed to be an empty string (e.g. =src is parsed as {"": "src"}).

• 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

  Important

  The file: directive is sandboxed and won’t reach anything outside the project directory (i.e. the directory containing setup.cfg/pyproject.toml).

  Attention

  When using the file: directive, please make sure that all necessary files are included in the sdist. You can do that via MANIFEST.in or using plugins such as setuptools-scm. Please have a look on Controlling files in the distribution for more information.

Metadata

Attention

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	36.7.0
install_requires	file:, list-semi		BETA [7]
extras_require	file:, section		BETA [3], [7]
python_requires	str	34.4.0
entry_points	file:, section	51.0.0
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		[6]
py_modules	list-comma	34.4.0
data_files	section	40.6.0	[5]

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.

[5]

data_files is deprecated and should be avoided. Please check Data Files Support for more information.

[6]

namespace_packages is deprecated in favour of native/implicit namespaces (PEP 420). Check the Python Packaging User Guide for more information.

[7] (1,2)

file: directives for reading requirements are supported since version 62.6. The format for the file resembles a requirements.txt file, however please keep in mind that all non-comment lines must conform with PEP 508 (pip-specify syntaxes, e.g. -c/-r/-e flags, are not supported). Library developers should avoid tightly pinning their dependencies to a specific version (e.g. via a “locked” requirements file).

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.