Creating a new package¶
Adding a new custom package is not much different from installing a third-party one.
Creating a traditional Zope 2 product¶
To create a traditional Zope 2 product, put it in the top-level products/ directory and re-start Zope. Nothing more should be required. As explained previously, products placed here will be found automatically at start-up, and their configure.zcml files will be executed automatically.
Creating an egg¶
Of course, if you are using products, you cannot benefit from the additional features of eggs, including automatic dependency management, distribution via the Cheese Shop and nested namespaces.
The easiest way to create a new egg is to use the paster*command, which we already used to create the buildout. To create a new basic package, with a top-level namespace (e.g. your company name) and a specific name, go to the *src/ directory and run:
$ cd src $ paster create -t plone myorg.mypackage
You will be asked a series of questions. Make sure that the namespace package and package name correspond to the name of the egg. In this case, the namespace package is myorg and the package name is mypackage. In general, answer False to the question on whether your package if "zip safe". Enter other metadata as requested.
You will now have:
- A setup.py which contains the metadata you entered
- A package in myorg.mypackage/myorg/mypackage. Your source code goes here.
- A skeleton configure.zcml, tests.py and a few other useful starting points.
- Some generic documentation in myorg.mypackage/docs.
Of course, you must also add this package to the buildout. In buildout.cfg, you might have:
[buildout] ... eggs = ... myorg.mypackage develop = src/myorg.mypackage
Unless you plan to include this package from another one (or use automatic ZCML loading, explained below), you probably also need a ZCML slug:
[instance] ... zcml = myorg.mypackage
Do not forget to re-run buildout after making the change:
Automate ZCML loading for your package¶
If you're not including your package from another one, you can still avoid having to include a ZCML slug in buildout.cfg for it. This is particulary useful to avoid unneccessary repetition of package names in buildout.cfg, which beginner integrators might easily overlook. From Plone 3.3 on, you can make your packages signal that their ZCML should be included by adding:
setup(... entry_points=""" [z3c.autoinclude.plugin] target = plone """
to their setup.py file. For further information, see the setuptools documentation about dynamic discovery of services and plugins.` <http://peak.telecommunity.com/DevCenter/setuptools#id19>`_
If your new package has explicit dependencies, you can list them in setup.py. That way, buildout will be able to download and install these as well. Dependencies are listed in the install_requires argument to the setup() method, By default, setuptools*is listed here, since we need this to support namespace packages. To add *sqlalchemy*0.3 (but not 0.4), and the *MySQL-Python driver, you could amend this to read:
install_requires=[ 'setuptools', 'sqlalchemy>=0.3,<0.4dev', 'MySQL-Python', ],
Uploading your egg to the Cheese Shop¶
If you want to share your package with the rest of the Python community and make it easy to install using tools like buildout and easy_install, you can upload the package to the Cheese Shop.
Before doing so, you should:
- Commit your latest changes and tag the release in Subversion, if applicable.
- Make sure the version number in setup.py is correct. This should use common conventions such as "1.0b2" for the second beta of version 1.0, or "2.1.3rc1" for the first release candidate of version 2.1.3.
- If you are using Mac OS X, run export COPY_EXTENDED_ATTRIBUTES_DISABLE=true on the shell first - otherwise, the egg will contain Mac OS X resource forks which cause problems if your egg is used on Windows.
When you are ready, run the following command from your package's directory (e.g. src/myorg.mypackage):
$ python setup.py egg_info -RDb "" sdist register upload
This will ask you to create a Cheese Shop account if you do not have one already. You can run this command as often as you'd like to release a new version (probably with a new version number).
Creating development releases¶
When working on a project, you might want to generate development
releases of a project to push to a staging server. Instead of
increasing the version number in the
setup.py file each time, you
can use the
egg_info command to name the release appropiately.
For a complete list of the available options, run:
$ python setup.py --help egg_info
If you're using subversion for version control, you can use the
revision numbers. For example, this will generate a targz package in
dist folder named
XXXX is a
$ python setup.py sdist egg_info -r
If you do nightly releases, tagging with the date is a good option:
$ python setup.py sdist egg_info -d
If you don't want to enter the full command everytime you make a release, you can use the setup.cfg file to set the defaults. For example:
[egg_info] tag_date = true