The PyMaemo team is pleased to announce the second beta release of PyMaemo for Fremantle!

This new release is available through the extras-devel repository, see installation instructions in
http://pymaemo.garage.maemo.org/sdk_installation.html#fremantle

What is it?

Python for Maemo (PyMaemo for short) main objective is to make possible to use Python programming language as the scripting and development language for Maemo Platform, providing a better alternative for fast prototyping and programming in Maemo environment besides the C programming language.

Python is for serious programming and to have fun. Python has a nice syntax, it is easy to learn and powerful enough for a vast range of applications, this is why we choose Python for Maemo.

What has changed?

New packages:

• python-mafw (0.1-1maemo1)
  • Python bindings for the Media Application Framework [1]
  • Supported API is very basic at the moment, and there are some bugs. Feedback is welcome!
• python-hildondesktop (0.0.3-1maemo1)
  • Python bindings for the home/status widgets API
• python-notify (0.1.1-2maemo1)
  • Python bindings for libnotify
• pyclutter (0.8.0-1maemo2)
  • Python bindings for the Clutter API [2]
  • Experimental package, waiting for developer feedback

Updated packages:

• gnome-python (2.26.1-1maemo1)
  • major upgrade, matching current Debian testing release;
  • feedback on this is welcome, as it replaces a fairly old version (2.18).
• pygtk (2.12.1-6maemo7)
  • Enable glade support.
• python2.5 (2.5.4-1maemo1)
  • Updated to latest upstream 2.5.x release.
  • add support to --install-layout=deb flag.
• python-central (0.6.11.1maemo1)
  • dependency needed by the new python-setuptools version.
• python-defaults (2.5.2-3maemo3)
  • Change PREVVER in debian/rules, avoiding old python2.5-minimal versions that had "/usr/bin/python" and thus conflicts with python-minimal.
• python-hildon (0.9.0-1maemo10)
  • lots of bug fixes
• python-setuptools (0.6c9-1maemo1)
  • add support to --install-layout=deb flag.

Bugs fixed: MB#4530 [3], MB#4450 [4], MB#4629 [5], MB#4628 [6],
MB#4647 [7], MB#4632 [8],  MB#4646 [9],  MB#4750 [10], MB#4749 [11],
MB#4791 [12]

Known issues

MB#4782 [13]: osso.Context causes segmentation fault
MB#4821 [14]: Cannot create HildonTouchSelector with single text column
MB#4824 [15]: python-mafw: source_browsing.py example does not work
MB#4839 [16]: python-mafw: mafw.Registry lacks list_plugins() method
MB#4849 [17]: python-mafw: MafwPluginDescriptorPublic structure is missing

We will not migrate to python2.6 in fremantle due to a (unresolved) bug (MB#4734 [18]), where a core SDK package explicitly conflicts with python >= 2.6, preventing any further upgrades from the 2.5.x series.

This release is supposed to be compatible with previous releases. If you have any issues regarding building your Python application on Fremantle, feel free to report it on the pymaemo-developers mailing list [19].

Acknowledgments

Thanks to everybody who helped making this release possible.

Bug reports, as always, should go to our Bugzilla [20]. Use the pymaemo-developers mailing list for help, feedback or suggestions.

References

[1] https://garage.maemo.org/projects/mafw/
[2] http://www.clutter-project.org/
[3] https://bugs.maemo.org/show_bug.cgi?id=4530
[4] https://bugs.maemo.org/show_bug.cgi?id=4450
[5] https://bugs.maemo.org/show_bug.cgi?id=4629
[6] https://bugs.maemo.org/show_bug.cgi?id=4628
[7] https://bugs.maemo.org/show_bug.cgi?id=4647
[8] https://bugs.maemo.org/show_bug.cgi?id=4632
[9] https://bugs.maemo.org/show_bug.cgi?id=4646
[10] https://bugs.maemo.org/show_bug.cgi?id=4750
[11] https://bugs.maemo.org/show_bug.cgi?id=4749
[12] https://bugs.maemo.org/show_bug.cgi?id=4791
[13] https://bugs.maemo.org/show_bug.cgi?id=4782
[14] https://bugs.maemo.org/show_bug.cgi?id=4821
[15] https://bugs.maemo.org/show_bug.cgi?id=4824
[16] https://bugs.maemo.org/show_bug.cgi?id=4839
[17] https://bugs.maemo.org/show_bug.cgi?id=4849
[18] https://bugs.maemo.org/show_bug.cgi?id=4734
[19] https://garage.maemo.org/mailman/listinfo/pymaemo-developers
[20] https://bugs.maemo.org/enter_bug.cgi?product=PyMaemo

Credits

This post was possible thanks to Anderson Lizardo, from PyMaemo team, who posted these informations on pymaemo-developers mailing list.

This summer I'm having the pleasure of working in Igalia (a spanish free software company) for a couple of months and they assigned me to an interesting project: developing Python bindings for MAFW library (a Maemo multimedia library that will be used in Fremantle release).

Having the opportunity to work both with C (yes, Python bindings are almost C code) and Python (it's a good practice to write unittest of all implemented methods) it's a good way to improve my knowledges in both languages and since I wasn't able to find much documentation about these kind of things, I'm going to share my own experiences.

What is a Binding?

A binding is a Python module, written in C language, that allows Python developers to call functions from existing C libraries from their python applications. It's just like a "bridge" from C world to Python one.

Why writing bindings?

There are a couple of reasons to write python bindings instead of writing a library in python language from scratch.

First of all I don't think is good duplicating code, so if a library already exists and it's written in C, why writing it again in another language? There's no reason. A lot of code already exist in C world and all we have to do is to create a bridge with python world.

Another good reason, in particular when a C library doesn't exist yet, is the fact that python code is slower than C code for some tasks (for example multimedia codecs). In these cases is good to implement the core library in C language and then create a python binding for it.

Coming next

As the title of this post says, this is only an introduction to the subjects I'm going to write about. If you have any particular request about any argument you would like to read, please feel free to leave me a comment. Next posts will talk about these things:

• A simple example of binding: I'll write a simple library in C language and I'll show how to create the relative python binding, providing complete source code and an example for python developers.
• Building and installing python bindings with distutils: I'll explain how to use distutils to build and install the binding (using the well know method "python setup.py install").
• Defining new types: this post will be about how to write new types in C language and being able to use them from python code.
• Using codegen to write bindings: I'll explain how to use codegen utils to automate lot of tasks, to generate the most part of binding code and how to customize the generated code using overrides.