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| author | alvyjudy <alvyjudy@gmail.com> | 2020-05-14 12:45:48 -0400 |
|---|---|---|
| committer | alvyjudy <alvyjudy@gmail.com> | 2020-05-14 12:45:48 -0400 |
| commit | f5c9ad1e228fb5751cb45171cd074c32890f9787 (patch) | |
| tree | 1169e92cd11d70a22257feeaab0070d134c6d530 /docs/userguide | |
| parent | a99713c017c77c215c278ad759796cdf928c89b7 (diff) | |
| download | python-setuptools-git-f5c9ad1e228fb5751cb45171cd074c32890f9787.tar.gz | |
docs: dedicate a file for miscel functionalities
these should be properly grouped but for now I'm just
leaving them here
Diffstat (limited to 'docs/userguide')
| -rw-r--r-- | docs/userguide/miscellaneous.txt | 1297 |
1 files changed, 0 insertions, 1297 deletions
diff --git a/docs/userguide/miscellaneous.txt b/docs/userguide/miscellaneous.txt index 5946662a..65e075cd 100644 --- a/docs/userguide/miscellaneous.txt +++ b/docs/userguide/miscellaneous.txt @@ -1,589 +1,3 @@ -Using ``find_packages()`` -------------------------- - -For simple projects, it's usually easy enough to manually add packages to -the ``packages`` argument of ``setup()``. However, for very large projects -(Twisted, PEAK, Zope, Chandler, etc.), it can be a big burden to keep the -package list updated. That's what ``setuptools.find_packages()`` is for. - -``find_packages()`` takes a source directory and two lists of package name -patterns to exclude and include. If omitted, the source directory defaults to -the same -directory as the setup script. Some projects use a ``src`` or ``lib`` -directory as the root of their source tree, and those projects would of course -use ``"src"`` or ``"lib"`` as the first argument to ``find_packages()``. (And -such projects also need something like ``package_dir={"": "src"}`` in their -``setup()`` arguments, but that's just a normal distutils thing.) - -Anyway, ``find_packages()`` walks the target directory, filtering by inclusion -patterns, and finds Python packages (any directory). Packages are only -recognized if they include an ``__init__.py`` file. Finally, exclusion -patterns are applied to remove matching packages. - -Inclusion and exclusion patterns are package names, optionally including -wildcards. For -example, ``find_packages(exclude=["*.tests"])`` will exclude all packages whose -last name part is ``tests``. Or, ``find_packages(exclude=["*.tests", -"*.tests.*"])`` will also exclude any subpackages of packages named ``tests``, -but it still won't exclude a top-level ``tests`` package or the children -thereof. In fact, if you really want no ``tests`` packages at all, you'll need -something like this:: - - find_packages(exclude=["*.tests", "*.tests.*", "tests.*", "tests"]) - -in order to cover all the bases. Really, the exclusion patterns are intended -to cover simpler use cases than this, like excluding a single, specified -package and its subpackages. - -Regardless of the parameters, the ``find_packages()`` -function returns a list of package names suitable for use as the ``packages`` -argument to ``setup()``, and so is usually the easiest way to set that -argument in your setup script. Especially since it frees you from having to -remember to modify your setup script whenever your project grows additional -top-level packages or subpackages. - -``find_namespace_packages()`` ------------------------------ -In Python 3.3+, ``setuptools`` also provides the ``find_namespace_packages`` variant -of ``find_packages``, which has the same function signature as -``find_packages``, but works with `PEP 420`_ compliant implicit namespace -packages. Here is a minimal setup script using ``find_namespace_packages``:: - - from setuptools import setup, find_namespace_packages - setup( - name="HelloWorld", - version="0.1", - packages=find_namespace_packages(), - ) - - -Keep in mind that according to PEP 420, you may have to either re-organize your -codebase a bit or define a few exclusions, as the definition of an implicit -namespace package is quite lenient, so for a project organized like so:: - - - ├── namespace - │ └── mypackage - │ ├── __init__.py - │ └── mod1.py - ├── setup.py - └── tests - └── test_mod1.py - -A naive ``find_namespace_packages()`` would install both ``namespace.mypackage`` and a -top-level package called ``tests``! One way to avoid this problem is to use the -``include`` keyword to whitelist the packages to include, like so:: - - from setuptools import setup, find_namespace_packages - - setup( - name="namespace.mypackage", - version="0.1", - packages=find_namespace_packages(include=["namespace.*"]) - ) - -Another option is to use the "src" layout, where all package code is placed in -the ``src`` directory, like so:: - - - ├── setup.py - ├── src - │ └── namespace - │ └── mypackage - │ ├── __init__.py - │ └── mod1.py - └── tests - └── test_mod1.py - -With this layout, the package directory is specified as ``src``, as such:: - - setup(name="namespace.mypackage", - version="0.1", - package_dir={"": "src"}, - packages=find_namespace_packages(where="src")) - -.. _PEP 420: https://www.python.org/dev/peps/pep-0420/ - -Automatic Script Creation -========================= - -Packaging and installing scripts can be a bit awkward with the distutils. For -one thing, there's no easy way to have a script's filename match local -conventions on both Windows and POSIX platforms. For another, you often have -to create a separate file just for the "main" script, when your actual "main" -is a function in a module somewhere. And even in Python 2.4, using the ``-m`` -option only works for actual ``.py`` files that aren't installed in a package. - -``setuptools`` fixes all of these problems by automatically generating scripts -for you with the correct extension, and on Windows it will even create an -``.exe`` file so that users don't have to change their ``PATHEXT`` settings. -The way to use this feature is to define "entry points" in your setup script -that indicate what function the generated script should import and run. For -example, to create two console scripts called ``foo`` and ``bar``, and a GUI -script called ``baz``, you might do something like this:: - - setup( - # other arguments here... - entry_points={ - "console_scripts": [ - "foo = my_package.some_module:main_func", - "bar = other_module:some_func", - ], - "gui_scripts": [ - "baz = my_package_gui:start_func", - ] - } - ) - -When this project is installed on non-Windows platforms (using "setup.py -install", "setup.py develop", or with pip), a set of ``foo``, ``bar``, -and ``baz`` scripts will be installed that import ``main_func`` and -``some_func`` from the specified modules. The functions you specify are -called with no arguments, and their return value is passed to -``sys.exit()``, so you can return an errorlevel or message to print to -stderr. - -On Windows, a set of ``foo.exe``, ``bar.exe``, and ``baz.exe`` launchers are -created, alongside a set of ``foo.py``, ``bar.py``, and ``baz.pyw`` files. The -``.exe`` wrappers find and execute the right version of Python to run the -``.py`` or ``.pyw`` file. - -You may define as many "console script" and "gui script" entry points as you -like, and each one can optionally specify "extras" that it depends on, that -will be added to ``sys.path`` when the script is run. For more information on -"extras", see the section below on `Declaring Extras`_. For more information -on "entry points" in general, see the section below on `Dynamic Discovery of -Services and Plugins`_. - - - -Declaring Dependencies -====================== - -``setuptools`` supports automatically installing dependencies when a package is -installed, and including information about dependencies in Python Eggs (so that -package management tools like pip can use the information). - -``setuptools`` and ``pkg_resources`` use a common syntax for specifying a -project's required dependencies. This syntax consists of a project's PyPI -name, optionally followed by a comma-separated list of "extras" in square -brackets, optionally followed by a comma-separated list of version -specifiers. A version specifier is one of the operators ``<``, ``>``, ``<=``, -``>=``, ``==`` or ``!=``, followed by a version identifier. Tokens may be -separated by whitespace, but any whitespace or nonstandard characters within a -project name or version identifier must be replaced with ``-``. - -Version specifiers for a given project are internally sorted into ascending -version order, and used to establish what ranges of versions are acceptable. -Adjacent redundant conditions are also consolidated (e.g. ``">1, >2"`` becomes -``">2"``, and ``"<2,<3"`` becomes ``"<2"``). ``"!="`` versions are excised from -the ranges they fall within. A project's version is then checked for -membership in the resulting ranges. (Note that providing conflicting conditions -for the same version (e.g. "<2,>=2" or "==2,!=2") is meaningless and may -therefore produce bizarre results.) - -Here are some example requirement specifiers:: - - docutils >= 0.3 - - # comment lines and \ continuations are allowed in requirement strings - BazSpam ==1.1, ==1.2, ==1.3, ==1.4, ==1.5, \ - ==1.6, ==1.7 # and so are line-end comments - - PEAK[FastCGI, reST]>=0.5a4 - - setuptools==0.5a7 - -The simplest way to include requirement specifiers is to use the -``install_requires`` argument to ``setup()``. It takes a string or list of -strings containing requirement specifiers. If you include more than one -requirement in a string, each requirement must begin on a new line. - -This has three effects: - -1. When your project is installed, either by using pip, ``setup.py install``, - or ``setup.py develop``, all of the dependencies not already installed will - be located (via PyPI), downloaded, built (if necessary), and installed. - -2. Any scripts in your project will be installed with wrappers that verify - the availability of the specified dependencies at runtime, and ensure that - the correct versions are added to ``sys.path`` (e.g. if multiple versions - have been installed). - -3. Python Egg distributions will include a metadata file listing the - dependencies. - -Note, by the way, that if you declare your dependencies in ``setup.py``, you do -*not* need to use the ``require()`` function in your scripts or modules, as -long as you either install the project or use ``setup.py develop`` to do -development work on it. (See `"Development Mode"`_ below for more details on -using ``setup.py develop``.) - -Dependencies that aren't in PyPI --------------------------------- - -.. warning:: - Dependency links support has been dropped by pip starting with version - 19.0 (released 2019-01-22). - -If your project depends on packages that don't exist on PyPI, you may still be -able to depend on them, as long as they are available for download as: - -- an egg, in the standard distutils ``sdist`` format, -- a single ``.py`` file, or -- a VCS repository (Subversion, Mercurial, or Git). - -You just need to add some URLs to the ``dependency_links`` argument to -``setup()``. - -The URLs must be either: - -1. direct download URLs, -2. the URLs of web pages that contain direct download links, or -3. the repository's URL - -In general, it's better to link to web pages, because it is usually less -complex to update a web page than to release a new version of your project. -You can also use a SourceForge ``showfiles.php`` link in the case where a -package you depend on is distributed via SourceForge. - -If you depend on a package that's distributed as a single ``.py`` file, you -must include an ``"#egg=project-version"`` suffix to the URL, to give a project -name and version number. (Be sure to escape any dashes in the name or version -by replacing them with underscores.) EasyInstall will recognize this suffix -and automatically create a trivial ``setup.py`` to wrap the single ``.py`` file -as an egg. - -In the case of a VCS checkout, you should also append ``#egg=project-version`` -in order to identify for what package that checkout should be used. You can -append ``@REV`` to the URL's path (before the fragment) to specify a revision. -Additionally, you can also force the VCS being used by prepending the URL with -a certain prefix. Currently available are: - -- ``svn+URL`` for Subversion, -- ``git+URL`` for Git, and -- ``hg+URL`` for Mercurial - -A more complete example would be: - - ``vcs+proto://host/path@revision#egg=project-version`` - -Be careful with the version. It should match the one inside the project files. -If you want to disregard the version, you have to omit it both in the -``requires`` and in the URL's fragment. - -This will do a checkout (or a clone, in Git and Mercurial parlance) to a -temporary folder and run ``setup.py bdist_egg``. - -The ``dependency_links`` option takes the form of a list of URL strings. For -example, this will cause a search of the specified page for eggs or source -distributions, if the package's dependencies aren't already installed:: - - setup( - ... - dependency_links=[ - "http://peak.telecommunity.com/snapshots/" - ], - ) - - -.. _Declaring Extras: - - -Declaring "Extras" (optional features with their own dependencies) ------------------------------------------------------------------- - -Sometimes a project has "recommended" dependencies, that are not required for -all uses of the project. For example, a project might offer optional PDF -output if ReportLab is installed, and reStructuredText support if docutils is -installed. These optional features are called "extras", and setuptools allows -you to define their requirements as well. In this way, other projects that -require these optional features can force the additional requirements to be -installed, by naming the desired extras in their ``install_requires``. - -For example, let's say that Project A offers optional PDF and reST support:: - - setup( - name="Project-A", - ... - extras_require={ - "PDF": ["ReportLab>=1.2", "RXP"], - "reST": ["docutils>=0.3"], - } - ) - -As you can see, the ``extras_require`` argument takes a dictionary mapping -names of "extra" features, to strings or lists of strings describing those -features' requirements. These requirements will *not* be automatically -installed unless another package depends on them (directly or indirectly) by -including the desired "extras" in square brackets after the associated project -name. (Or if the extras were listed in a requirement spec on the "pip install" -command line.) - -Extras can be used by a project's `entry points`_ to specify dynamic -dependencies. For example, if Project A includes a "rst2pdf" script, it might -declare it like this, so that the "PDF" requirements are only resolved if the -"rst2pdf" script is run:: - - setup( - name="Project-A", - ... - entry_points={ - "console_scripts": [ - "rst2pdf = project_a.tools.pdfgen [PDF]", - "rst2html = project_a.tools.htmlgen", - # more script entry points ... - ], - } - ) - -Projects can also use another project's extras when specifying dependencies. -For example, if project B needs "project A" with PDF support installed, it -might declare the dependency like this:: - - setup( - name="Project-B", - install_requires=["Project-A[PDF]"], - ... - ) - -This will cause ReportLab to be installed along with project A, if project B is -installed -- even if project A was already installed. In this way, a project -can encapsulate groups of optional "downstream dependencies" under a feature -name, so that packages that depend on it don't have to know what the downstream -dependencies are. If a later version of Project A builds in PDF support and -no longer needs ReportLab, or if it ends up needing other dependencies besides -ReportLab in order to provide PDF support, Project B's setup information does -not need to change, but the right packages will still be installed if needed. - -Note, by the way, that if a project ends up not needing any other packages to -support a feature, it should keep an empty requirements list for that feature -in its ``extras_require`` argument, so that packages depending on that feature -don't break (due to an invalid feature name). For example, if Project A above -builds in PDF support and no longer needs ReportLab, it could change its -setup to this:: - - setup( - name="Project-A", - ... - extras_require={ - "PDF": [], - "reST": ["docutils>=0.3"], - } - ) - -so that Package B doesn't have to remove the ``[PDF]`` from its requirement -specifier. - -.. _Platform Specific Dependencies: - - -Declaring platform specific dependencies ----------------------------------------- - -Sometimes a project might require a dependency to run on a specific platform. -This could to a package that back ports a module so that it can be used in -older python versions. Or it could be a package that is required to run on a -specific operating system. This will allow a project to work on multiple -different platforms without installing dependencies that are not required for -a platform that is installing the project. - -For example, here is a project that uses the ``enum`` module and ``pywin32``:: - - setup( - name="Project", - ... - install_requires=[ - "enum34;python_version<'3.4'", - "pywin32 >= 1.0;platform_system=='Windows'" - ] - ) - -Since the ``enum`` module was added in Python 3.4, it should only be installed -if the python version is earlier. Since ``pywin32`` will only be used on -windows, it should only be installed when the operating system is Windows. -Specifying version requirements for the dependencies is supported as normal. - -The environmental markers that may be used for testing platform types are -detailed in `PEP 508`_. - -.. _PEP 508: https://www.python.org/dev/peps/pep-0508/ - -Including Data Files -==================== - -The distutils have traditionally allowed installation of "data files", which -are placed in a platform-specific location. However, the most common use case -for data files distributed with a package is for use *by* the package, usually -by including the data files in the package directory. - -Setuptools offers three ways to specify data files to be included in your -packages. First, you can simply use the ``include_package_data`` keyword, -e.g.:: - - from setuptools import setup, find_packages - setup( - ... - 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. -(They can also be tracked by a revision control system, using an appropriate -plugin. See the section below on `Adding Support for Revision Control -Systems`_ for information on how to write such plugins.) - -If you want finer-grained control over what files are included (for example, -if you have documentation files in your package directories and want to exclude -them from installation), then you can also use the ``package_data`` keyword, -e.g.:: - - from setuptools import setup, find_packages - setup( - ... - package_data={ - # If any package contains *.txt or *.rst files, include them: - "": ["*.txt", "*.rst"], - # And include any *.msg files found in the "hello" package, too: - "hello": ["*.msg"], - } - ) - -The ``package_data`` argument is a dictionary that maps from package names to -lists of glob patterns. The globs may include subdirectory names, if the data -files are contained in a subdirectory of the package. For example, if the -package tree looks like this:: - - setup.py - src/ - mypkg/ - __init__.py - mypkg.txt - data/ - somefile.dat - otherdata.dat - -The setuptools setup file might look like this:: - - from setuptools import setup, find_packages - setup( - ... - packages=find_packages("src"), # include all packages under src - package_dir={"": "src"}, # tell distutils packages are under src - - package_data={ - # If any package contains *.txt files, include them: - "": ["*.txt"], - # And include any *.dat files found in the "data" subdirectory - # of the "mypkg" package, also: - "mypkg": ["data/*.dat"], - } - ) - -Notice that if you list patterns in ``package_data`` under the empty string, -these patterns are used to find files in every package, even ones that also -have their own patterns listed. Thus, in the above example, the ``mypkg.txt`` -file gets included even though it's not listed in the patterns for ``mypkg``. - -Also notice that if you use paths, you *must* use a forward slash (``/``) as -the path separator, even if you are on Windows. Setuptools automatically -converts slashes to appropriate platform-specific separators at build time. - -If datafiles are contained in a subdirectory of a package that isn't a package -itself (no ``__init__.py``), then the subdirectory names (or ``*``) are required -in the ``package_data`` argument (as shown above with ``"data/*.dat"``). - -When building an ``sdist``, the datafiles are also drawn from the -``package_name.egg-info/SOURCES.txt`` file, so make sure that this is removed if -the ``setup.py`` ``package_data`` list is updated before calling ``setup.py``. - -(Note: although the ``package_data`` argument was previously only available in -``setuptools``, it was also added to the Python ``distutils`` package as of -Python 2.4; there is `some documentation for the feature`__ available on the -python.org website. If using the setuptools-specific ``include_package_data`` -argument, files specified by ``package_data`` will *not* be automatically -added to the manifest unless they are listed in the MANIFEST.in file.) - -__ https://docs.python.org/3/distutils/setupscript.html#installing-package-data - -Sometimes, the ``include_package_data`` or ``package_data`` options alone -aren't sufficient to precisely define what files you want included. For -example, you may want to include package README files in your revision control -system and source distributions, but exclude them from being installed. So, -setuptools offers an ``exclude_package_data`` option as well, that allows you -to do things like this:: - - from setuptools import setup, find_packages - setup( - ... - packages=find_packages("src"), # include all packages under src - package_dir={"": "src"}, # tell distutils packages are under src - - include_package_data=True, # include everything in source control - - # ...but exclude README.txt from all packages - exclude_package_data={"": ["README.txt"]}, - ) - -The ``exclude_package_data`` option is a dictionary mapping package names to -lists of wildcard patterns, just like the ``package_data`` option. And, just -as with that option, a key of ``""`` will apply the given pattern(s) to all -packages. However, any files that match these patterns will be *excluded* -from installation, even if they were listed in ``package_data`` or were -included as a result of using ``include_package_data``. - -In summary, the three options allow you to: - -``include_package_data`` - Accept all data files and directories matched by ``MANIFEST.in``. - -``package_data`` - Specify additional patterns to match files that may or may - not be matched by ``MANIFEST.in`` or found in source control. - -``exclude_package_data`` - Specify patterns for data files and directories that should *not* be - included when a package is installed, even if they would otherwise have - been included due to the use of the preceding options. - -NOTE: Due to the way the distutils build process works, a data file that you -include in your project and then stop including may be "orphaned" in your -project's build directories, requiring you to run ``setup.py clean --all`` to -fully remove them. This may also be important for your users and contributors -if they track intermediate revisions of your project using Subversion; be sure -to let them know when you make changes that remove files from inclusion so they -can run ``setup.py clean --all``. - -Accessing Data Files at Runtime -------------------------------- - -Typically, existing programs manipulate a package's ``__file__`` attribute in -order to find the location of data files. However, this manipulation isn't -compatible with PEP 302-based import hooks, including importing from zip files -and Python Eggs. It is strongly recommended that, if you are using data files, -you should use the :ref:`ResourceManager API` of ``pkg_resources`` to access -them. The ``pkg_resources`` module is distributed as part of setuptools, so if -you're using setuptools to distribute your package, there is no reason not to -use its resource management API. See also `Importlib Resources`_ for -a quick example of converting code that uses ``__file__`` to use -``pkg_resources`` instead. - -.. _Importlib Resources: https://docs.python.org/3/library/importlib.html#module-importlib.resources - - -Non-Package Data Files ----------------------- - -Historically, ``setuptools`` by way of ``easy_install`` would encapsulate data -files from the distribution into the egg (see `the old docs -<https://github.com/pypa/setuptools/blob/52aacd5b276fedd6849c3a648a0014f5da563e93/docs/setuptools.txt#L970-L1001>`_). As eggs are deprecated and pip-based installs -fall back to the platform-specific location for installing data files, there is -no supported facility to reliably retrieve these resources. - -Instead, the PyPA recommends that any data files you wish to be accessible at -run time be included in the package. - - Automatic Resource Extraction ----------------------------- @@ -621,76 +35,6 @@ files, or Python plus C, you really don't need this. You've got to be using either C or an external program that needs "real" files in your project before there's any possibility of ``eager_resources`` being relevant to your project. - -Extensible Applications and Frameworks -====================================== - - -.. _Entry Points: - -Dynamic Discovery of Services and Plugins ------------------------------------------ - -``setuptools`` supports creating libraries that "plug in" to extensible -applications and frameworks, by letting you register "entry points" in your -project that can be imported by the application or framework. - -For example, suppose that a blogging tool wants to support plugins -that provide translation for various file types to the blog's output format. -The framework might define an "entry point group" called ``blogtool.parsers``, -and then allow plugins to register entry points for the file extensions they -support. - -This would allow people to create distributions that contain one or more -parsers for different file types, and then the blogging tool would be able to -find the parsers at runtime by looking up an entry point for the file -extension (or mime type, or however it wants to). - -Note that if the blogging tool includes parsers for certain file formats, it -can register these as entry points in its own setup script, which means it -doesn't have to special-case its built-in formats. They can just be treated -the same as any other plugin's entry points would be. - -If you're creating a project that plugs in to an existing application or -framework, you'll need to know what entry points or entry point groups are -defined by that application or framework. Then, you can register entry points -in your setup script. Here are a few examples of ways you might register an -``.rst`` file parser entry point in the ``blogtool.parsers`` entry point group, -for our hypothetical blogging tool:: - - setup( - # ... - entry_points={"blogtool.parsers": ".rst = some_module:SomeClass"} - ) - - setup( - # ... - entry_points={"blogtool.parsers": [".rst = some_module:a_func"]} - ) - - setup( - # ... - entry_points=""" - [blogtool.parsers] - .rst = some.nested.module:SomeClass.some_classmethod [reST] - """, - extras_require=dict(reST="Docutils>=0.3.5") - ) - -The ``entry_points`` argument to ``setup()`` accepts either a string with -``.ini``-style sections, or a dictionary mapping entry point group names to -either strings or lists of strings containing entry point specifiers. An -entry point specifier consists of a name and value, separated by an ``=`` -sign. The value consists of a dotted module name, optionally followed by a -``:`` and a dotted identifier naming an object within the module. It can -also include a bracketed list of "extras" that are required for the entry -point to be used. When the invoking application or framework requests loading -of an entry point, any requirements implied by the associated extras will be -passed to ``pkg_resources.require()``, so that an appropriate error message -can be displayed if the needed package(s) are missing. (Of course, the -invoking app or framework can ignore such errors if it wants to make an entry -point optional if a requirement isn't installed.) - Defining Additional Metadata ---------------------------- @@ -705,107 +49,6 @@ for many of the ``setup()`` arguments it adds. See the section below on `Creating distutils Extensions`_ for more details, especially the subsection on `Adding new EGG-INFO Files`_. - -"Development Mode" -================== - -Under normal circumstances, the ``distutils`` assume that you are going to -build a distribution of your project, not use it in its "raw" or "unbuilt" -form. If you were to use the ``distutils`` that way, you would have to rebuild -and reinstall your project every time you made a change to it during -development. - -Another problem that sometimes comes up with the ``distutils`` is that you may -need to do development on two related projects at the same time. You may need -to put both projects' packages in the same directory to run them, but need to -keep them separate for revision control purposes. How can you do this? - -Setuptools allows you to deploy your projects for use in a common directory or -staging area, but without copying any files. Thus, you can edit each project's -code in its checkout directory, and only need to run build commands when you -change a project's C extensions or similarly compiled files. You can even -deploy a project into another project's checkout directory, if that's your -preferred way of working (as opposed to using a common independent staging area -or the site-packages directory). - -To do this, use the ``setup.py develop`` command. It works very similarly to -``setup.py install``, except that it doesn't actually install anything. -Instead, it creates a special ``.egg-link`` file in the deployment directory, -that links to your project's source code. And, if your deployment directory is -Python's ``site-packages`` directory, it will also update the -``easy-install.pth`` file to include your project's source code, thereby making -it available on ``sys.path`` for all programs using that Python installation. - -If you have enabled the ``use_2to3`` flag, then of course the ``.egg-link`` -will not link directly to your source code when run under Python 3, since -that source code would be made for Python 2 and not work under Python 3. -Instead the ``setup.py develop`` will build Python 3 code under the ``build`` -directory, and link there. This means that after doing code changes you will -have to run ``setup.py build`` before these changes are picked up by your -Python 3 installation. - -In addition, the ``develop`` command creates wrapper scripts in the target -script directory that will run your in-development scripts after ensuring that -all your ``install_requires`` packages are available on ``sys.path``. - -You can deploy the same project to multiple staging areas, e.g. if you have -multiple projects on the same machine that are sharing the same project you're -doing development work. - -When you're done with a given development task, you can remove the project -source from a staging area using ``setup.py develop --uninstall``, specifying -the desired staging area if it's not the default. - -There are several options to control the precise behavior of the ``develop`` -command; see the section on the `develop`_ command below for more details. - -Note that you can also apply setuptools commands to non-setuptools projects, -using commands like this:: - - python -c "import setuptools; with open('setup.py') as f: exec(compile(f.read(), 'setup.py', 'exec'))" develop - -That is, you can simply list the normal setup commands and options following -the quoted part. - - -Distributing a ``setuptools``-based project -=========================================== - -Detailed instructions to distribute a setuptools project can be found at -`Packaging project tutorials`_. - -.. _Packaging project tutorials: https://packaging.python.org/tutorials/packaging-projects/#generating-distribution-archives - -Before you begin, make sure you have the latest versions of setuptools and wheel:: - - pip install --upgrade setuptools wheel - -To build a setuptools project, run this command from the same directory where -setup.py is located:: - - setup.py sdist bdist_wheel - -This will generate distribution archives in the `dist` directory. - -Before you upload the generated archives make sure you're registered on -https://test.pypi.org/account/register/. You will also need to verify your email -to be able to upload any packages. -You should install twine to be able to upload packages:: - - pip install --upgrade twine - -Now, to upload these archives, run:: - - twine upload --repository-url https://test.pypi.org/legacy/ dist/* - -To install your newly uploaded package ``example_pkg``, you can use pip:: - - pip install --index-url https://test.pypi.org/simple/ example_pkg - -If you have issues at any point, please refer to `Packaging project tutorials`_ -for clarification. - - Setting the ``zip_safe`` flag ----------------------------- @@ -849,543 +92,3 @@ correctly when installed as a zipfile, correct any problems if you can, and then make an explicit declaration of ``True`` or ``False`` for the ``zip_safe`` flag, so that it will not be necessary for ``bdist_egg`` to try to guess whether your project can work as a zipfile. - -.. _Namespace Packages: - -Namespace Packages ------------------- - -Sometimes, a large package is more useful if distributed as a collection of -smaller eggs. However, Python does not normally allow the contents of a -package to be retrieved from more than one location. "Namespace packages" -are a solution for this problem. When you declare a package to be a namespace -package, it means that the package has no meaningful contents in its -``__init__.py``, and that it is merely a container for modules and subpackages. - -The ``pkg_resources`` runtime will then automatically ensure that the contents -of namespace packages that are spread over multiple eggs or directories are -combined into a single "virtual" package. - -The ``namespace_packages`` argument to ``setup()`` lets you declare your -project's namespace packages, so that they will be included in your project's -metadata. The argument should list the namespace packages that the egg -participates in. For example, the ZopeInterface project might do this:: - - setup( - # ... - namespace_packages=["zope"] - ) - -because it contains a ``zope.interface`` package that lives in the ``zope`` -namespace package. Similarly, a project for a standalone ``zope.publisher`` -would also declare the ``zope`` namespace package. When these projects are -installed and used, Python will see them both as part of a "virtual" ``zope`` -package, even though they will be installed in different locations. - -Namespace packages don't have to be top-level packages. For example, Zope 3's -``zope.app`` package is a namespace package, and in the future PEAK's -``peak.util`` package will be too. - -Note, by the way, that your project's source tree must include the namespace -packages' ``__init__.py`` files (and the ``__init__.py`` of any parent -packages), in a normal Python package layout. These ``__init__.py`` files -*must* contain the line:: - - __import__("pkg_resources").declare_namespace(__name__) - -This code ensures that the namespace package machinery is operating and that -the current package is registered as a namespace package. - -You must NOT include any other code and data in a namespace package's -``__init__.py``. Even though it may appear to work during development, or when -projects are installed as ``.egg`` files, it will not work when the projects -are installed using "system" packaging tools -- in such cases the -``__init__.py`` files will not be installed, let alone executed. - -You must include the ``declare_namespace()`` line in the ``__init__.py`` of -*every* project that has contents for the namespace package in question, in -order to ensure that the namespace will be declared regardless of which -project's copy of ``__init__.py`` is loaded first. If the first loaded -``__init__.py`` doesn't declare it, it will never *be* declared, because no -other copies will ever be loaded! - -Tagging and "Daily Build" or "Snapshot" Releases ------------------------------------------------- - -When a set of related projects are under development, it may be important to -track finer-grained version increments than you would normally use for e.g. -"stable" releases. While stable releases might be measured in dotted numbers -with alpha/beta/etc. status codes, development versions of a project often -need to be tracked by revision or build number or even build date. This is -especially true when projects in development need to refer to one another, and -therefore may literally need an up-to-the-minute version of something! - -To support these scenarios, ``setuptools`` allows you to "tag" your source and -egg distributions by adding one or more of the following to the project's -"official" version identifier: - -* A manually-specified pre-release tag, such as "build" or "dev", or a - manually-specified post-release tag, such as a build or revision number - (``--tag-build=STRING, -bSTRING``) - -* An 8-character representation of the build date (``--tag-date, -d``), as - a postrelease tag - -You can add these tags by adding ``egg_info`` and the desired options to -the command line ahead of the ``sdist`` or ``bdist`` commands that you want -to generate a daily build or snapshot for. See the section below on the -`egg_info`_ command for more details. - -(Also, before you release your project, be sure to see the section above on -`Specifying Your Project's Version`_ for more information about how pre- and -post-release tags affect how version numbers are interpreted. This is -important in order to make sure that dependency processing tools will know -which versions of your project are newer than others.) - -Finally, if you are creating builds frequently, and either building them in a -downloadable location or are copying them to a distribution server, you should -probably also check out the `rotate`_ command, which lets you automatically -delete all but the N most-recently-modified distributions matching a glob -pattern. So, you can use a command line like:: - - setup.py egg_info -rbDEV bdist_egg rotate -m.egg -k3 - -to build an egg whose version info includes "DEV-rNNNN" (where NNNN is the -most recent Subversion revision that affected the source tree), and then -delete any egg files from the distribution directory except for the three -that were built most recently. - -If you have to manage automated builds for multiple packages, each with -different tagging and rotation policies, you may also want to check out the -`alias`_ command, which would let each package define an alias like ``daily`` -that would perform the necessary tag, build, and rotate commands. Then, a -simpler script or cron job could just run ``setup.py daily`` in each project -directory. (And, you could also define sitewide or per-user default versions -of the ``daily`` alias, so that projects that didn't define their own would -use the appropriate defaults.) - -Generating Source Distributions -------------------------------- - -``setuptools`` enhances the distutils' default algorithm for source file -selection with pluggable endpoints for looking up files to include. If you are -using a revision control system, and your source distributions only need to -include files that you're tracking in revision control, use a corresponding -plugin instead of writing a ``MANIFEST.in`` file. See the section below on -`Adding Support for Revision Control Systems`_ for information on plugins. - -If you need to include automatically generated files, or files that are kept in -an unsupported revision control system, you'll need to create a ``MANIFEST.in`` -file to specify any files that the default file location algorithm doesn't -catch. See the distutils documentation for more information on the format of -the ``MANIFEST.in`` file. - -But, be sure to ignore any part of the distutils documentation that deals with -``MANIFEST`` or how it's generated from ``MANIFEST.in``; setuptools shields you -from these issues and doesn't work the same way in any case. Unlike the -distutils, setuptools regenerates the source distribution manifest file -every time you build a source distribution, and it builds it inside the -project's ``.egg-info`` directory, out of the way of your main project -directory. You therefore need not worry about whether it is up-to-date or not. - -Indeed, because setuptools' approach to determining the contents of a source -distribution is so much simpler, its ``sdist`` command omits nearly all of -the options that the distutils' more complex ``sdist`` process requires. For -all practical purposes, you'll probably use only the ``--formats`` option, if -you use any option at all. - - -Making "Official" (Non-Snapshot) Releases -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -When you make an official release, creating source or binary distributions, -you will need to override the tag settings from ``setup.cfg``, so that you -don't end up registering versions like ``foobar-0.7a1.dev-r34832``. This is -easy to do if you are developing on the trunk and using tags or branches for -your releases - just make the change to ``setup.cfg`` after branching or -tagging the release, so the trunk will still produce development snapshots. - -Alternately, if you are not branching for releases, you can override the -default version options on the command line, using something like:: - - setup.py egg_info -Db "" sdist bdist_egg - -The first part of this command (``egg_info -Db ""``) will override the -configured tag information, before creating source and binary eggs. Thus, these -commands will use the plain version from your ``setup.py``, without adding the -build designation string. - -Of course, if you will be doing this a lot, you may wish to create a personal -alias for this operation, e.g.:: - - setup.py alias -u release egg_info -Db "" - -You can then use it like this:: - - setup.py release sdist bdist_egg - -Or of course you can create more elaborate aliases that do all of the above. -See the sections below on the `egg_info`_ and `alias`_ commands for more ideas. - -Distributing Extensions compiled with Cython --------------------------------------------- - -``setuptools`` will detect at build time whether Cython is installed or not. -If Cython is not found ``setuptools`` will ignore pyx files. - -To ensure Cython is available, include Cython in the build-requires section -of your pyproject.toml:: - - [build-system] - requires=[..., "cython"] - -Built with pip 10 or later, that declaration is sufficient to include Cython -in the build. For broader compatibility, declare the dependency in your -setup-requires of setup.cfg:: - - [options] - setup_requires = - ... - cython - -As long as Cython is present in the build environment, ``setuptools`` includes -transparent support for building Cython extensions, as -long as extensions are defined using ``setuptools.Extension``. - -If you follow these rules, you can safely list ``.pyx`` files as the source -of your ``Extension`` objects in the setup script. If it is, then ``setuptools`` -will use it. - -Of course, for this to work, your source distributions must include the C -code generated by Cython, as well as your original ``.pyx`` files. This means -that you will probably want to include current ``.c`` files in your revision -control system, rebuilding them whenever you check changes in for the ``.pyx`` -source files. This will ensure that people tracking your project in a revision -control system will be able to build it even if they don't have Cython -installed, and that your source releases will be similarly usable with or -without Cython. - --------------------------------- -Extending and Reusing Setuptools --------------------------------- - -Creating ``distutils`` Extensions -================================= - -It can be hard to add new commands or setup arguments to the distutils. But -the ``setuptools`` package makes it a bit easier, by allowing you to distribute -a distutils extension as a separate project, and then have projects that need -the extension just refer to it in their ``setup_requires`` argument. - -With ``setuptools``, your distutils extension projects can hook in new -commands and ``setup()`` arguments just by defining "entry points". These -are mappings from command or argument names to a specification of where to -import a handler from. (See the section on `Dynamic Discovery of Services and -Plugins`_ above for some more background on entry points.) - - -Adding Commands ---------------- - -You can add new ``setup`` commands by defining entry points in the -``distutils.commands`` group. For example, if you wanted to add a ``foo`` -command, you might add something like this to your distutils extension -project's setup script:: - - setup( - # ... - entry_points={ - "distutils.commands": [ - "foo = mypackage.some_module:foo", - ], - }, - ) - -(Assuming, of course, that the ``foo`` class in ``mypackage.some_module`` is -a ``setuptools.Command`` subclass.) - -Once a project containing such entry points has been activated on ``sys.path``, -(e.g. by running "install" or "develop" with a site-packages installation -directory) the command(s) will be available to any ``setuptools``-based setup -scripts. It is not necessary to use the ``--command-packages`` option or -to monkeypatch the ``distutils.command`` package to install your commands; -``setuptools`` automatically adds a wrapper to the distutils to search for -entry points in the active distributions on ``sys.path``. In fact, this is -how setuptools' own commands are installed: the setuptools project's setup -script defines entry points for them! - -Adding ``setup()`` Arguments ----------------------------- - -.. warning:: Adding arguments to setup is discouraged as such arguments - are only supported through imperative execution and not supported through - declarative config. - -Sometimes, your commands may need additional arguments to the ``setup()`` -call. You can enable this by defining entry points in the -``distutils.setup_keywords`` group. For example, if you wanted a ``setup()`` -argument called ``bar_baz``, you might add something like this to your -distutils extension project's setup script:: - - setup( - # ... - entry_points={ - "distutils.commands": [ - "foo = mypackage.some_module:foo", - ], - "distutils.setup_keywords": [ - "bar_baz = mypackage.some_module:validate_bar_baz", - ], - }, - ) - -The idea here is that the entry point defines a function that will be called -to validate the ``setup()`` argument, if it's supplied. The ``Distribution`` -object will have the initial value of the attribute set to ``None``, and the -validation function will only be called if the ``setup()`` call sets it to -a non-None value. Here's an example validation function:: - - def assert_bool(dist, attr, value): - """Verify that value is True, False, 0, or 1""" - if bool(value) != value: - raise DistutilsSetupError( - "%r must be a boolean value (got %r)" % (attr,value) - ) - -Your function should accept three arguments: the ``Distribution`` object, -the attribute name, and the attribute value. It should raise a -``DistutilsSetupError`` (from the ``distutils.errors`` module) if the argument -is invalid. Remember, your function will only be called with non-None values, -and the default value of arguments defined this way is always None. So, your -commands should always be prepared for the possibility that the attribute will -be ``None`` when they access it later. - -If more than one active distribution defines an entry point for the same -``setup()`` argument, *all* of them will be called. This allows multiple -distutils extensions to define a common argument, as long as they agree on -what values of that argument are valid. - -Also note that as with commands, it is not necessary to subclass or monkeypatch -the distutils ``Distribution`` class in order to add your arguments; it is -sufficient to define the entry points in your extension, as long as any setup -script using your extension lists your project in its ``setup_requires`` -argument. - - -Customizing Distribution Options --------------------------------- - -Plugins may wish to extend or alter the options on a Distribution object to -suit the purposes of that project. For example, a tool that infers the -``Distribution.version`` from SCM-metadata may need to hook into the -option finalization. To enable this feature, Setuptools offers an entry -point "setuptools.finalize_distribution_options". That entry point must -be a callable taking one argument (the Distribution instance). - -If the callable has an ``.order`` property, that value will be used to -determine the order in which the hook is called. Lower numbers are called -first and the default is zero (0). - -Plugins may read, alter, and set properties on the distribution, but each -plugin is encouraged to load the configuration/settings for their behavior -independently. - - -Adding new EGG-INFO Files -------------------------- - -Some extensible applications or frameworks may want to allow third parties to -develop plugins with application or framework-specific metadata included in -the plugins' EGG-INFO directory, for easy access via the ``pkg_resources`` -metadata API. The easiest way to allow this is to create a distutils extension -to be used from the plugin projects' setup scripts (via ``setup_requires``) -that defines a new setup keyword, and then uses that data to write an EGG-INFO -file when the ``egg_info`` command is run. - -The ``egg_info`` command looks for extension points in an ``egg_info.writers`` -group, and calls them to write the files. Here's a simple example of a -distutils extension defining a setup argument ``foo_bar``, which is a list of -lines that will be written to ``foo_bar.txt`` in the EGG-INFO directory of any -project that uses the argument:: - - setup( - # ... - entry_points={ - "distutils.setup_keywords": [ - "foo_bar = setuptools.dist:assert_string_list", - ], - "egg_info.writers": [ - "foo_bar.txt = setuptools.command.egg_info:write_arg", - ], - }, - ) - -This simple example makes use of two utility functions defined by setuptools -for its own use: a routine to validate that a setup keyword is a sequence of -strings, and another one that looks up a setup argument and writes it to -a file. Here's what the writer utility looks like:: - - def write_arg(cmd, basename, filename): - argname = os.path.splitext(basename)[0] - value = getattr(cmd.distribution, argname, None) - if value is not None: - value = "\n".join(value) + "\n" - cmd.write_or_delete_file(argname, filename, value) - -As you can see, ``egg_info.writers`` entry points must be a function taking -three arguments: a ``egg_info`` command instance, the basename of the file to -write (e.g. ``foo_bar.txt``), and the actual full filename that should be -written to. - -In general, writer functions should honor the command object's ``dry_run`` -setting when writing files, and use the ``distutils.log`` object to do any -console output. The easiest way to conform to this requirement is to use -the ``cmd`` object's ``write_file()``, ``delete_file()``, and -``write_or_delete_file()`` methods exclusively for your file operations. See -those methods' docstrings for more details. - -Adding Support for Revision Control Systems -------------------------------------------------- - -If the files you want to include in the source distribution are tracked using -Git, Mercurial or SVN, you can use the following packages to achieve that: - -- Git and Mercurial: `setuptools_scm <https://pypi.org/project/setuptools_scm/>`_ -- SVN: `setuptools_svn <https://pypi.org/project/setuptools_svn/>`_ - -If you would like to create a plugin for ``setuptools`` to find files tracked -by another revision control system, you can do so by adding an entry point to -the ``setuptools.file_finders`` group. The entry point should be a function -accepting a single directory name, and should yield all the filenames within -that directory (and any subdirectories thereof) that are under revision -control. - -For example, if you were going to create a plugin for a revision control system -called "foobar", you would write a function something like this: - -.. code-block:: python - - def find_files_for_foobar(dirname): - # loop to yield paths that start with `dirname` - -And you would register it in a setup script using something like this:: - - entry_points={ - "setuptools.file_finders": [ - "foobar = my_foobar_module:find_files_for_foobar", - ] - } - -Then, anyone who wants to use your plugin can simply install it, and their -local setuptools installation will be able to find the necessary files. - -It is not necessary to distribute source control plugins with projects that -simply use the other source control system, or to specify the plugins in -``setup_requires``. When you create a source distribution with the ``sdist`` -command, setuptools automatically records what files were found in the -``SOURCES.txt`` file. That way, recipients of source distributions don't need -to have revision control at all. However, if someone is working on a package -by checking out with that system, they will need the same plugin(s) that the -original author is using. - -A few important points for writing revision control file finders: - -* Your finder function MUST return relative paths, created by appending to the - passed-in directory name. Absolute paths are NOT allowed, nor are relative - paths that reference a parent directory of the passed-in directory. - -* Your finder function MUST accept an empty string as the directory name, - meaning the current directory. You MUST NOT convert this to a dot; just - yield relative paths. So, yielding a subdirectory named ``some/dir`` under - the current directory should NOT be rendered as ``./some/dir`` or - ``/somewhere/some/dir``, but *always* as simply ``some/dir`` - -* Your finder function SHOULD NOT raise any errors, and SHOULD deal gracefully - with the absence of needed programs (i.e., ones belonging to the revision - control system itself. It *may*, however, use ``distutils.log.warn()`` to - inform the user of the missing program(s). - -Specifying Your Project's Version ---------------------------------- - -Setuptools can work well with most versioning schemes; there are, however, a -few special things to watch out for, in order to ensure that setuptools and -other tools can always tell what version of your package is newer than another -version. Knowing these things will also help you correctly specify what -versions of other projects your project depends on. - -A version consists of an alternating series of release numbers and pre-release -or post-release tags. A release number is a series of digits punctuated by -dots, such as ``2.4`` or ``0.5``. Each series of digits is treated -numerically, so releases ``2.1`` and ``2.1.0`` are different ways to spell the -same release number, denoting the first subrelease of release 2. But ``2.10`` -is the *tenth* subrelease of release 2, and so is a different and newer release -from ``2.1`` or ``2.1.0``. Leading zeros within a series of digits are also -ignored, so ``2.01`` is the same as ``2.1``, and different from ``2.0.1``. - -Following a release number, you can have either a pre-release or post-release -tag. Pre-release tags make a version be considered *older* than the version -they are appended to. So, revision ``2.4`` is *newer* than revision ``2.4c1``, -which in turn is newer than ``2.4b1`` or ``2.4a1``. Postrelease tags make -a version be considered *newer* than the version they are appended to. So, -revisions like ``2.4-1`` and ``2.4pl3`` are newer than ``2.4``, but are *older* -than ``2.4.1`` (which has a higher release number). - -A pre-release tag is a series of letters that are alphabetically before -"final". Some examples of prerelease tags would include ``alpha``, ``beta``, -``a``, ``c``, ``dev``, and so on. You do not have to place a dot or dash -before the prerelease tag if it's immediately after a number, but it's okay to -do so if you prefer. Thus, ``2.4c1`` and ``2.4.c1`` and ``2.4-c1`` all -represent release candidate 1 of version ``2.4``, and are treated as identical -by setuptools. - -In addition, there are three special prerelease tags that are treated as if -they were the letter ``c``: ``pre``, ``preview``, and ``rc``. So, version -``2.4rc1``, ``2.4pre1`` and ``2.4preview1`` are all the exact same version as -``2.4c1``, and are treated as identical by setuptools. - -A post-release tag is either a series of letters that are alphabetically -greater than or equal to "final", or a dash (``-``). Post-release tags are -generally used to separate patch numbers, port numbers, build numbers, revision -numbers, or date stamps from the release number. For example, the version -``2.4-r1263`` might denote Subversion revision 1263 of a post-release patch of -version ``2.4``. Or you might use ``2.4-20051127`` to denote a date-stamped -post-release. - -Notice that after each pre or post-release tag, you are free to place another -release number, followed again by more pre- or post-release tags. For example, -``0.6a9.dev-r41475`` could denote Subversion revision 41475 of the in- -development version of the ninth alpha of release 0.6. Notice that ``dev`` is -a pre-release tag, so this version is a *lower* version number than ``0.6a9``, -which would be the actual ninth alpha of release 0.6. But the ``-r41475`` is -a post-release tag, so this version is *newer* than ``0.6a9.dev``. - -For the most part, setuptools' interpretation of version numbers is intuitive, -but here are a few tips that will keep you out of trouble in the corner cases: - -* Don't stick adjoining pre-release tags together without a dot or number - between them. Version ``1.9adev`` is the ``adev`` prerelease of ``1.9``, - *not* a development pre-release of ``1.9a``. Use ``.dev`` instead, as in - ``1.9a.dev``, or separate the prerelease tags with a number, as in - ``1.9a0dev``. ``1.9a.dev``, ``1.9a0dev``, and even ``1.9.a.dev`` are - identical versions from setuptools' point of view, so you can use whatever - scheme you prefer. - -* If you want to be certain that your chosen numbering scheme works the way - you think it will, you can use the ``pkg_resources.parse_version()`` function - to compare different version numbers:: - - >>> from pkg_resources import parse_version - >>> parse_version("1.9.a.dev") == parse_version("1.9a0dev") - True - >>> parse_version("2.1-rc2") < parse_version("2.1") - True - >>> parse_version("0.6a9dev-r41475") < parse_version("0.6a9") - True - -Once you've decided on a version numbering scheme for your project, you can -have setuptools automatically tag your in-development releases with various -pre- or post-release tags. See the following sections for more details: - -* `Tagging and "Daily Build" or "Snapshot" Releases`_ -* The `egg_info`_ command
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