5.1.Creating RPM packages¶

The RPM format is used by many popular Linux distributions, including Red Hat,SuSE, and Mandrake. If one of these (or any of the other RPM-based Linuxdistributions) is your usual environment, creating RPM packages for other usersof that same distribution is trivial. Depending on the complexity of your moduledistribution and differences between Linux distributions, you may also be ableto create RPMs that work on different RPM-based distributions.

The usual way to create an RPM of your module distribution is to run thebdist_rpm command:

pythonsetup.pybdist_rpm

or thebdist command with the--format option:

pythonsetup.pybdist--formats=rpm

The former allows you to specify RPM-specific options; the latter allows you toeasily specify multiple formats in one run. If you need to do both, you canexplicitly specify multiplebdist_* commands and their options:

pythonsetup.pybdist_rpm--packager="John Doe <jdoe@example.org>" \bdist_dumb--dumb-option=foo

Creating RPM packages is driven by a.spec file, much as using theDistutils is driven by the setup script. To make your life easier, thebdist_rpm command normally creates a.spec file based on theinformation you supply in the setup script, on the command line, and in anyDistutils configuration files. Various options and sections in the.spec file are derived from options in the setup script as follows:

Additionally, there are many options in.spec files that don’t havecorresponding options in the setup script. Most of these are handled throughoptions to thebdist_rpm command as follows:

Obviously, supplying even a few of these options on the command-line would betedious and error-prone, so it’s usually best to put them in the setupconfiguration file,setup.cfg—see sectionWriting the Setup Configuration File. Ifyou distribute or package many Python module distributions, you might want toput options that apply to all of them in your personal Distutils configurationfile (~/.pydistutils.cfg). If you want to temporarily disablethis file, you can pass the--no-user-cfg option tosetup.py.

There are three steps to building a binary RPM package, all of which arehandled automatically by the Distutils:

1. create a.spec file, which describes the package (analogous to theDistutils setup script; in fact, much of the information in the setup scriptwinds up in the.spec file)

2. create the source RPM

3. create the “binary” RPM (which may or may not contain binary code, dependingon whether your module distribution contains Python extensions)

Normally, RPM bundles the last two steps together; when you use the Distutils,all three steps are typically bundled together.

If you wish, you can separate these three steps. You can use the--spec-only option to makebdist_rpm just create the.spec file and exit; in this case, the.spec file will bewritten to the “distribution directory”—normallydist/, butcustomizable with the--dist-dir option. (Normally, the.specfile winds up deep in the “build tree,” in a temporary directory created bybdist_rpm.)

5.2.Cross-compiling on Windows¶

Starting with Python 2.6, distutils is capable of cross-compiling betweenWindows platforms. In practice, this means that with the correct toolsinstalled, you can use a 32bit version of Windows to create 64bit extensionsand vice-versa.

To build for an alternate platform, specify the--plat-name optionto the build command. Valid values are currently ‘win32’, and ‘win-amd64’.For example, on a 32bit version of Windows, you could execute:

pythonsetup.pybuild--plat-name=win-amd64

to build a 64bit version of your extension.

To cross-compile, you must download the Python source code and cross-compilePython itself for the platform you are targeting - it is not possible from abinary installation of Python (as the .lib etc file for other platforms arenot included.) In practice, this means the user of a 32 bit operatingsystem will need to use Visual Studio 2008 to open thePCbuild/PCbuild.sln solution in the Python source tree and build the“x64” configuration of the ‘pythoncore’ project before cross-compilingextensions is possible.

Note that by default, Visual Studio 2008 does not install 64bit compilers ortools. You may need to reexecute the Visual Studio setup process and selectthese tools (using Control Panel->[Add/Remove] Programs is a convenient way tocheck or modify your existing install.)