Edit File: quickstart.rst
========================== ``setuptools`` Quickstart ========================== Installation ============ To install the latest version of setuptools, use:: pip install --upgrade setuptools Python packaging at a glance ============================ The landscape of Python packaging is shifting and ``Setuptools`` has evolved to only provide backend support, no longer being the de-facto packaging tool in the market. All python package must provide a ``pyproject.toml`` and specify the backend (build system) it wants to use. The distribution can then be generated with whatever tools that provides a ``build sdist``-alike functionality. While this may appear cumbersome, given the added pieces, it in fact tremendously enhances the portability of your package. The change is driven under :pep:`PEP 517 <517#build-requirements>`. To learn more about Python packaging in general, navigate to the :ref:`bottom <packaging-resources>` of this page. Basic Use ========= For basic use of setuptools, you will need a ``pyproject.toml`` with the exact following info, which declares you want to use ``setuptools`` to package your project: .. code-block:: toml [build-system] requires = ["setuptools", "wheel"] build-backend = "setuptools.build_meta" Then, you will need a ``setup.cfg`` or ``setup.py`` to specify your package information, such as metadata, contents, dependencies, etc. Here we demonstrate the minimum .. tab:: setup.cfg .. code-block:: ini [metadata] name = mypackage version = 0.0.1 [options] packages = mypackage install_requires = requests importlib; python_version == "2.6" .. tab:: setup.py .. code-block:: python from setuptools import setup setup( name='mypackage', version='0.0.1', packages=['mypackage'], install_requires=[ 'requests', 'importlib; python_version == "2.6"', ], ) This is what your project would look like:: ~/mypackage/ pyproject.toml setup.cfg # or setup.py mypackage/__init__.py Then, you need an builder, such as :std:doc:`PyPA build <pypa-build:index>` which you can obtain via ``pip install build``. After downloading it, invoke the builder:: python -m build You now have your distribution ready (e.g. a ``tar.gz`` file and a ``.whl`` file in the ``dist`` directory), which you can upload to PyPI! Of course, before you release your project to PyPI, you'll want to add a bit more information to your setup script to help people find or learn about your project. And maybe your project will have grown by then to include a few dependencies, and perhaps some data files and scripts. In the next few sections, we will walk through those additional but essential information you need to specify to properly package your project. Automatic package discovery =========================== For simple projects, it's usually easy enough to manually add packages to the ``packages`` keyword in ``setup.cfg``. However, for very large projects , it can be a big burden to keep the package list updated. ``setuptools`` therefore provides two convenient tools to ease the burden: :literal:`find:\ ` and :literal:`find_namespace:\ `. To use it in your project: .. code-block:: ini [options] packages = find: [options.packages.find] #optional include=pkg1, pkg2 exclude=pk3, pk4 When you pass the above information, alongside other necessary ones, ``setuptools`` walks through the directory specified in ``where`` (omitted here as the package reside in current directory) and filters the packages it can find following the ``include`` (default to none), then remove those that match the ``exclude`` and return a list of Python packages. Note that each entry in the ``[options.packages.find]`` is optional. The above setup also allows you to adopt a ``src/`` layout. For more details and advanced use, go to :ref:`package_discovery` Entry points and automatic script creation =========================================== Setuptools support automatic creation of scripts upon installation, that runs code within your package if you specify them with the ``entry_points`` keyword. This is what allows you to run commands like ``pip install`` instead of having to type ``python -m pip install``. To accomplish this, add the entry_points keyword in your ``setup.cfg``: .. code-block:: ini [options.entry_points] console_scripts = main = mypkg:some_func When this project is installed, a ``main`` script will be installed and will invoke the ``some_func`` in the ``__init__.py`` file when called by the user. For detailed usage, including managing the additional or optional dependencies, go to :doc:`entry_point`. Dependency management ===================== ``setuptools`` supports automatically installing dependencies when a package is installed. The simplest way to include requirement specifiers is to use the ``install_requires`` argument to ``setup.cfg``. It takes a string or list of strings containing requirement specifiers (A version specifier is one of the operators <, >, <=, >=, == or !=, followed by a version identifier): .. code-block:: ini [options] install_requires = docutils >= 0.3 requests <= 0.4 When your project is installed, all of the dependencies not already installed will be located (via PyPI), downloaded, built (if necessary), and installed. This, of course, is a simplified scenarios. ``setuptools`` also provide additional keywords such as ``setup_requires`` that allows you to install dependencies before running the script, and ``extras_requires`` that take care of those needed by automatically generated scripts. It also provides mechanisms to handle dependencies that are not in PyPI. For more advanced use, see :doc:`dependency_management` .. _Including Data Files: Including Data Files ==================== The distutils have traditionally allowed installation of "data files", which are placed in a platform-specific location. Setuptools offers three ways to specify data files to be included in your packages. For the simplest use, you can simply use the ``include_package_data`` keyword: .. code-block:: ini [options] include_package_data = True This tells setuptools to install any data files it finds in your packages. The data files must be specified via the distutils' ``MANIFEST.in`` file. For more details, see :doc:`datafiles` Development mode ================ ``setuptools`` allows you to install a package without copying any files to your interpreter directory (e.g. the ``site-packages`` directory). This allows you to modify your source code and have the changes take effect without you having to rebuild and reinstall. This is currently incompatible with PEP 517 and therefore it requires a ``setup.py`` script with the following content:: import setuptools setuptools.setup() Then:: pip install --editable . This creates a link file in your interpreter site package directory which associate with your source code. For more information, see :doc:`development_mode`. Uploading your package to PyPI ============================== After generating the distribution files, next step would be to upload your distribution so others can use it. This functionality is provided by `twine <https://pypi.org/project/twine/>`_ and we will only demonstrate the basic use here. Transitioning from ``setup.py`` to ``setup.cfg`` ================================================ To avoid executing arbitrary scripts and boilerplate code, we are transitioning into a full-fledged ``setup.cfg`` to declare your package information instead of running ``setup()``. This inevitably brings challenges due to a different syntax. Here we provide a quick guide to understanding how ``setup.cfg`` is parsed by ``setuptool`` to ease the pain of transition. .. _packaging-resources: Resources on Python packaging ============================= Packaging in Python is hard. Here we provide a list of links for those that want to learn more.