Differences between revisions 28 and 51 (spanning 23 versions)
Revision 28 as of 2009-09-15 20:37:25
Size: 5371
Editor: HenriLeFoll
Comment: TableOfContents
Revision 51 as of 2020-04-04 07:29:00
Size: 6153
Editor: ?JochenSprickerhof
Comment: Fix alioth links
Deletions are marked like this. Additions are marked like this.
Line 1: Line 1:
## page was renamed from DebianPythonFAQ
Line 2: Line 3:
#pragma section-numbers 2
Line 4: Line 7:
This is the FAQ of the debian-python@l.d.o mailing list. It is of particular interest to members of the [[Teams/PythonModulesTeam| Debian Python Modules Team]]. Please also look at [[DebianPython]] for introductory info. This is the FAQ of the debian-python@l.d.o mailing list. It is of particular interest to members of the [[Teams/PythonModulesTeam| Debian Python Modules Team]]. Please also look at [[Python]] for introductory info.
Line 6: Line 9:
<<TableOfContents(2)>> <<TableOfContents(3)>>
Line 8: Line 11:
= What are the projects and documentation available ? = == What are the projects and documentation available ? ==
Line 10: Line 13:
If you're interested in help packaging Python itself, there's [[http://alioth.debian.org/projects/pkg-python|pkg-python]] but if you want to help with the Python modules or packaging a new one, you should look at [[Teams/PythonModulesTeam| Debian Python Modules Team]] project. Both groups discuss its activities in the same debian-python@l.d.o mailing list. If you're interested in help packaging Python itself, there's [[https://salsa.debian.org/cpython-team|cpython-team]] but if you want to help with the Python modules or packaging a new one, you should look at [[Teams/PythonModulesTeam| Debian Python Modules Team]] project. Both groups discuss its activities in the same debian-python@l.d.o mailing list.
Line 12: Line 15:
== python-modules == === python-modules ===
Line 14: Line 17:
The Debian Python Modules Team has its own [[http://python-modules.alioth.debian.org/python-modules-policy.html|policy]], but keep in mind that they follow [[http://www.debian.org/doc/packaging-manuals/python-policy/|Debian Python Policy]] and of course [[http://www.debian.org/doc/debian-policy/|Debian Policy]] too. The Debian Python Modules Team has its own [[https://salsa.debian.org/python-team/tools/python-modules/-/blob/master/policy.rst|policy]], but keep in mind that they follow [[http://www.debian.org/doc/packaging-manuals/python-policy/|Debian Python Policy]] and of course [[http://www.debian.org/doc/debian-policy/|Debian Policy]] too.
Line 16: Line 19:
= Multiple python versions support = == Multiple python versions support ==
Line 18: Line 21:
Debian supports several versions of Python simultaneously. Some packages include modules only for the default version, while others provide modules for all available. Source packages may provide several binary packages for each version of Python or build a single one that suits all. Debian supports several versions of Python simultaneously. Some packages include modules only for the default version, while others provide modules for all available. These are generally all provided within a single binary package, although in the past multiple packages were sometimes used.
Line 22: Line 25:
== Build dependencies ==
Traditionally, build dependencies for Python extension modules included development packages for all versions of Python they were built for. For compiled modules you still have to specify each dependency separately. For Python-only modules the sole python-dev is sufficient if they use Python-based build system (like the very used distutils), python-support dependency in turn will automagically manage late-bytecompilation.
=== Build dependencies ===
For compiled modules you need to depend on python-all-dev, and python-all-dbg.
For Python-only modules the sole python-all is sufficient if they use Python-based build system (like the very used distutils).
A helper such as dh_python2 (or the deprecated python-support and python-central) will automagically manage bytecompilation.
Line 25: Line 30:
= Note on bytecompilation for pure Python modules = == Note on bytecompilation for pure Python modules ==
Line 27: Line 32:
As python-support introduce late-bytecompilation, no .pyc/.pyo files shall be shipped in your package. You do no need to spend build time for generating them. With distutils use the "--no-compile -O0" options; if you are using the CDBS class, everything is already done for you. Beware some upstream sources that contain a setup.cfg which override your build options (see [[http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=360848|#360848]]), then you will have to patch it. In all cases, python-support will remove those files if they are generated. As the helpers manage late-bytecompilation, no .pyc/.pyo files shall be shipped in your package. You do no need to spend build time for generating them. With distutils use the "--no-compile -O0" options; dh and the python CDBS classes know how to handle this. Beware some upstream sources that contain a setup.cfg which override your build options (see DebianBug:360848), then you will have to patch it. In all cases, dh_python2 or python-support will remove those files if they are generated.
Line 29: Line 34:
== What is python-support? == === What are dh_python2 and dh_python3? ===
Line 31: Line 36:
Python-support is a tool to handle byte-compilation of python modules when there are several python versions installed on the system. dh_python{2,3} are the python helpers included in the python package since 2.6.6-3.
Line 33: Line 38:
See /usr/share/doc/python-support/README.gz or [[http://svn.debian.org/viewsvn/collab-maint/deb-maint/python-support/trunk/README|SVN README]] for up-to-date information. dh_python2 differs from python-support, in including the per-python-version symlink farm within the binary package, only requiring byte-compilation at install time. Packages using dh_python2 with public modules must be rebuilt when Debian changes the supported Python versions (this should never happen after 2.7).
Line 35: Line 40:
== What is python-central? == They can also guess dependencies from requires.txt, for setuptools/distutils packages.
Line 37: Line 42:
Package that contains some helper scripts for building and installing python modules independent of the current installed Python version. Instructions for transitioning to dh_python2 from [[Python/PythonSupportToDHPython2|python-support]] and [[Python/PyCentral2DhPython2|python-central]].
Line 39: Line 44:
Some information about python-central can be found here:
http://python-modules.alioth.debian.org/python-central_howto.txt
See [[DebianMan:1/dh_python2|dh_python2(1)]] or [[DebianMan:1/dh_python3|dh_python3(1)]] for more details.
Line 42: Line 46:
== Should I use python-support or python-central? == === What is python-support? ===
Line 44: Line 48:
Most people prefer python-support, because it is better so use that. :) Python-support is a (now removed) tool to handle byte-compilation of python modules when there are several python versions installed on the system.
Line 46: Line 50:
Some statistics (the number of packages using each method), as of December 16, 2007: === What is python-central? ===

Python-central is a (now removed) package that contains some helper scripts for building and installing python modules independent of the current installed Python version.

=== Should I use dh_pythonX, python-support or python-central? ===

dh_python2 is recommended for new Python 2 packages.
dh_python3 is the only helper for Python3.
python-support and python-central are deprecated.

Some statistics (the number of packages using each method - lower number is contrib), as of 2014-04-22:
Line 48: Line 62:
~/python-modules$ grep python-support packages/*/trunk/debian/control | wc -l
124
~/python-modules$ grep python-central packages/*/trunk/debian/control | wc -l
62
~$ build-rdeps dh-python | grep total
Found a total of 283 reverse build-depend(s) for dh-python.
Found a total of 2 reverse build-depend(s) for dh-python.
~$ build-rdeps python-support | grep total
Found a total of 4 reverse build-depend(s) for python-support.
Found a total of 585 reverse build-depend(s) for python-support.
Line 54: Line 70:
NB! Only python-support numbers are accurate, as other packages may build-depend indirectly on dh-python (for python3) or not use it at all (for python2)
Line 55: Line 72:
= Python eggs = == Python eggs ==
Line 57: Line 74:
== What are Python eggs? == === What are Python eggs? ===
Line 61: Line 78:
== How should we package Python eggs? == === How should we package Python eggs? ===
Line 63: Line 80:
We don't want to provide ".egg" files within the .deb. However we want to make the "egg meta-information" available so that users can use eggs if they so wish. For that you need to pass the option "--single-version-externally-managed" to the "setup.py install" call. We don't want to provide ".egg" files within the .deb. However we want to make the "egg meta-information" available so that users can use eggs if they so wish. Python >= 2.5 does that by default in distutils. For setuptools based setup.py you need to pass the option "--single-version-externally-managed" to the "setup.py install" call.
Line 65: Line 82:
Packages relying on CDBS can do that this way: ==== with dh_python2 ====
This [[http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=652617|bug report]] provides relevant information:

 * Add {{{*.egg-info/*}}} to {{{debian/clean}}}. (This requires Debhelper compatibility >= 7, declared in {{{debian/compat}}}.)
 * Add {{{extend-diff-ignore="^[^/]+\.egg-info/"}}} to debian/source/options. (This requires Debian source package format 3.0, declared in {{{debian/source/format}}}.)

==== with CDBS and setuptools ====
Packages relying on CDBS and setuptools can do that this way:
Line 71: Line 95:
== How do we add Egg support to a package that doesnt support it yet? == == Package naming ==
Line 73: Line 97:
Basicly, you should modify setup.py to use the setup function of "setuptools" instead of "distutils". Of course, you must then Build-Depends on "python-setuptools (>= 0.6a9)" which is the first version supporting the egg-info directories. For binary packages of Python libraries, the [[Python/LibraryStyleGuide#debian.2Fcontrol|Python Library Style Guide]] has some answers. For source package names, there is no consensus on whether they should be "foo" for a package named "foo" on the Python package index, or "python-foo".
Line 75: Line 99:
Check the following links for documentation about setuptools and creation of Eggs:
 * http://peak.telecommunity.com/DevCenter/setuptools
 * http://peak.telecommunity.com/DevCenter/PythonEggs#building-eggs

Example of minimal patch:
{{{
--- elementtree-1.2.6.old/setup.py 2006-04-18 12:25:33.000000000 +0000
+++ elementtree-1.2.6/setup.py 2006-04-18 12:26:30.000000000 +0000
@@ -7,6 +7,7 @@
 #

 from distutils.core import setup
+from setuptools import setup

 try:
     # add download_url syntax to distutils
}}}

Adding "egg support" is only required in some specific cases: when another software uses the python module via an egg and when this egg support is not yet integrated upstream.

Debian Python FAQ

This is the FAQ of the debian-python@l.d.o mailing list. It is of particular interest to members of the Debian Python Modules Team. Please also look at Python for introductory info.

1. What are the projects and documentation available ?

If you're interested in help packaging Python itself, there's cpython-team but if you want to help with the Python modules or packaging a new one, you should look at Debian Python Modules Team project. Both groups discuss its activities in the same debian-python@l.d.o mailing list.

1.1. python-modules

The Debian Python Modules Team has its own policy, but keep in mind that they follow Debian Python Policy and of course Debian Policy too.

2. Multiple python versions support

Debian supports several versions of Python simultaneously. Some packages include modules only for the default version, while others provide modules for all available. These are generally all provided within a single binary package, although in the past multiple packages were sometimes used.

The general trend is to reduce that diversity and provide modules for all Python versions available within Debian using the following guidelines.

2.1. Build dependencies

For compiled modules you need to depend on python-all-dev, and python-all-dbg. For Python-only modules the sole python-all is sufficient if they use Python-based build system (like the very used distutils). A helper such as dh_python2 (or the deprecated python-support and python-central) will automagically manage bytecompilation.

3. Note on bytecompilation for pure Python modules

As the helpers manage late-bytecompilation, no .pyc/.pyo files shall be shipped in your package. You do no need to spend build time for generating them. With distutils use the "--no-compile -O0" options; dh and the python CDBS classes know how to handle this. Beware some upstream sources that contain a setup.cfg which override your build options (see 360848), then you will have to patch it. In all cases, dh_python2 or python-support will remove those files if they are generated.

3.1. What are dh_python2 and dh_python3?

dh_python{2,3} are the python helpers included in the python package since 2.6.6-3.

dh_python2 differs from python-support, in including the per-python-version symlink farm within the binary package, only requiring byte-compilation at install time. Packages using dh_python2 with public modules must be rebuilt when Debian changes the supported Python versions (this should never happen after 2.7).

They can also guess dependencies from requires.txt, for setuptools/distutils packages.

Instructions for transitioning to dh_python2 from python-support and python-central.

See dh_python2(1) or dh_python3(1) for more details.

3.2. What is python-support?

Python-support is a (now removed) tool to handle byte-compilation of python modules when there are several python versions installed on the system.

3.3. What is python-central?

Python-central is a (now removed) package that contains some helper scripts for building and installing python modules independent of the current installed Python version.

3.4. Should I use dh_pythonX, python-support or python-central?

dh_python2 is recommended for new Python 2 packages. dh_python3 is the only helper for Python3. python-support and python-central are deprecated.

Some statistics (the number of packages using each method - lower number is contrib), as of 2014-04-22:

~$ build-rdeps dh-python | grep total
Found a total of 283 reverse build-depend(s) for dh-python.
Found a total of 2 reverse build-depend(s) for dh-python.
~$ build-rdeps python-support | grep total
Found a total of 4 reverse build-depend(s) for python-support.
Found a total of 585 reverse build-depend(s) for python-support.

NB! Only python-support numbers are accurate, as other packages may build-depend indirectly on dh-python (for python3) or not use it at all (for python2)

4. Python eggs

4.1. What are Python eggs?

http://peak.telecommunity.com/DevCenter/PythonEggs

4.2. How should we package Python eggs?

We don't want to provide ".egg" files within the .deb. However we want to make the "egg meta-information" available so that users can use eggs if they so wish. Python >= 2.5 does that by default in distutils. For setuptools based setup.py you need to pass the option "--single-version-externally-managed" to the "setup.py install" call.

4.2.1. with dh_python2

This bug report provides relevant information:

  • Add *.egg-info/* to debian/clean. (This requires Debhelper compatibility >= 7, declared in debian/compat.)

  • Add extend-diff-ignore="^[^/]+\.egg-info/" to debian/source/options. (This requires Debian source package format 3.0, declared in debian/source/format.)

4.2.2. with CDBS and setuptools

Packages relying on CDBS and setuptools can do that this way:

# Install egg-info directories
DEB_PYTHON_INSTALL_ARGS_ALL += --single-version-externally-managed

5. Package naming

For binary packages of Python libraries, the Python Library Style Guide has some answers. For source package names, there is no consensus on whether they should be "foo" for a package named "foo" on the Python package index, or "python-foo".


CategoryPermalink