[libvirt] libvirt and python3
I've seen a bunch of interest in python3 [1,2,3]. Has anybody started thinking about python3 bindings for libvirt? Dave [1] https://fedoraproject.org/wiki/Python3 [2] https://wiki.gnome.org/GnomeGoals/Python3Porting [3] https://wiki.archlinux.org/index.php/DeveloperWiki:Python_Todo_List
On Thu, Jul 18, 2013 at 1:13 PM, Dave Allan <dallan@redhat.com> wrote:
I've seen a bunch of interest in python3 [1,2,3]. Has anybody started thinking about python3 bindings for libvirt?
While not really answering your question, I would like to see the build system a little more flexible with regards to Python binding generation. Currently you have to configure libvirt and it will generate bindings for the python it detects (or is supplied) and if you want to change that you need to rebuild the entire source tree. It'd be nice in the future to be able to build against multiple Python's without having to reconfigure and rebuild. Count this as a "would like to see python 3.x support but don't have time to personally do it." Just a thought. -- Doug Goldstein
On 19.07.2013 04:04, Doug Goldstein wrote:
On Thu, Jul 18, 2013 at 1:13 PM, Dave Allan <dallan@redhat.com> wrote:
I've seen a bunch of interest in python3 [1,2,3]. Has anybody started thinking about python3 bindings for libvirt?
While not really answering your question, I would like to see the build system a little more flexible with regards to Python binding generation. Currently you have to configure libvirt and it will generate bindings for the python it detects (or is supplied) and if you want to change that you need to rebuild the entire source tree. It'd be nice in the future to be able to build against multiple Python's without having to reconfigure and rebuild.
That's because python bindings need the client implementation. But I agree that it would be nice if one could just: make -C python to build the bindings. To answer Dave's question, I'm not really into python but isn't 2to3 enough? Michal
On Fri, Jul 19, 2013 at 07:26:09AM +0200, Michal Privoznik wrote:
On 19.07.2013 04:04, Doug Goldstein wrote:
On Thu, Jul 18, 2013 at 1:13 PM, Dave Allan <dallan@redhat.com> wrote:
I've seen a bunch of interest in python3 [1,2,3]. Has anybody started thinking about python3 bindings for libvirt?
While not really answering your question, I would like to see the build system a little more flexible with regards to Python binding generation. Currently you have to configure libvirt and it will generate bindings for the python it detects (or is supplied) and if you want to change that you need to rebuild the entire source tree. It'd be nice in the future to be able to build against multiple Python's without having to reconfigure and rebuild.
That's because python bindings need the client implementation. But I agree that it would be nice if one could just:
make -C python
to build the bindings.
To answer Dave's question, I'm not really into python but isn't 2to3 enough?
2to3 will take a python2 file & spit out a reasonable python3 file. The issue is that, IMHO, we don't want to be in the business of maintaining 2 sets of python bindings. For any C code, I think we want to make sure we use #if conditionals to minimize the extra burden of python3. For the py code, I think we should also aim to try to support 2 & 3 with one set of code. There are some modules you can import which give you access to some python3 style apis from python2, which could help. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On Fri, Jul 19, 2013 at 09:58:30AM +0100, Daniel P. Berrange wrote:
On Fri, Jul 19, 2013 at 07:26:09AM +0200, Michal Privoznik wrote:
On 19.07.2013 04:04, Doug Goldstein wrote:
On Thu, Jul 18, 2013 at 1:13 PM, Dave Allan <dallan@redhat.com> wrote:
I've seen a bunch of interest in python3 [1,2,3]. Has anybody started thinking about python3 bindings for libvirt?
While not really answering your question, I would like to see the build system a little more flexible with regards to Python binding generation. Currently you have to configure libvirt and it will generate bindings for the python it detects (or is supplied) and if you want to change that you need to rebuild the entire source tree. It'd be nice in the future to be able to build against multiple Python's without having to reconfigure and rebuild.
That's because python bindings need the client implementation. But I agree that it would be nice if one could just:
make -C python
to build the bindings.
yes that would be nicer, the problem is that python version detection is done in configure.ac .
To answer Dave's question, I'm not really into python but isn't 2to3 enough?
2to3 will take a python2 file & spit out a reasonable python3 file. The issue is that, IMHO, we don't want to be in the business of maintaining 2 sets of python bindings. For any C code, I think we want to make sure we use #if conditionals to minimize the extra burden of python3. For the py code, I think we should also aim to try to support 2 & 3 with one set of code. There are some modules you can import which give you access to some python3 style apis from python2, which could help.
When I ported libxml2, I had to do a couple of tricks but honnestly not too many, and I didn't try to use any portability layer. On the other hand debugging a lot of the nasty stuff that 2to3 generated making it improper for python2 or just changing the semantic wasn't too fun. That's why if i were to do it now on libvirt I would process from the set of patches I used for libxml2. Daniel -- Daniel Veillard | Open Source and Standards, Red Hat veillard@redhat.com | libxml Gnome XML XSLT toolkit http://xmlsoft.org/ http://veillard.com/ | virtualization library http://libvirt.org/
On Thu, Jul 18, 2013 at 02:13:59PM -0400, Dave Allan wrote:
I've seen a bunch of interest in python3 [1,2,3]. Has anybody started thinking about python3 bindings for libvirt?
I'm not going to do any work on it, but I have two requirements here - We should not end up maintaining two separate bindings. We want to minimize the duplication of code to as great an extent as possible, as close to zero extra overhead as possible in fact. The generator will help, but there's still hand-written C code & python code that we really don't want to be duplicating - We should be able to build both python2 & python3 at once. ie you should not need to run ./configure --with-python=2|3, in order to choose. We should detect both python2 & python3 at once & build both if both are available. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On Fri, Jul 19, 2013 at 10:01:15AM +0100, Daniel P. Berrange wrote:
On Thu, Jul 18, 2013 at 02:13:59PM -0400, Dave Allan wrote:
I've seen a bunch of interest in python3 [1,2,3]. Has anybody started thinking about python3 bindings for libvirt?
I'm not going to do any work on it, but I have two requirements here
- We should not end up maintaining two separate bindings. We want to minimize the duplication of code to as great an extent as possible, as close to zero extra overhead as possible in fact. The generator will help, but there's still hand-written C code & python code that we really don't want to be duplicating
- We should be able to build both python2 & python3 at once. ie you should not need to run ./configure --with-python=2|3, in order to choose. We should detect both python2 & python3 at once & build both if both are available.
For my $.02, ack to both of those points. Dave
On Thu, Jul 18, 2013 at 02:13:59PM -0400, Dave Allan wrote:
I've seen a bunch of interest in python3 [1,2,3]. Has anybody started thinking about python3 bindings for libvirt?
Dave
[1] https://fedoraproject.org/wiki/Python3 [2] https://wiki.gnome.org/GnomeGoals/Python3Porting [3] https://wiki.archlinux.org/index.php/DeveloperWiki:Python_Todo_List
libvirt python bindings are autogenerated for the most part. The tool is inherited from libxml2. I have made the port of libxml2 to be python3 compatible for libxml2-1.9.1 back in April http://xmlsoft.org/news.html there have been a few subsequent patches to that port after 1.9.1 but it's mostly okay. Of course the libxml2 patches won't apply 1-1 to libvirt but the main parts should and i tripped on all the breakage left by 2to3 so we should be able to do that without too much crazyness. Someone contributed the equivalent for libxslt which uses the same system, but I hadn't yet the time to review and process them. I was somehow hoping to do those patches for libvirt but my plate is fairly full ATM. I guess the core work based on my libxml2 set of patches should take me 2-3 full days (as in not doing anything else !), since that wasn't looking urgent, I didn't try to arrange to spend that time, yet... libxml2 of course is compatible with python 2, back to 2.4 ... Daniel -- Daniel Veillard | Open Source and Standards, Red Hat veillard@redhat.com | libxml Gnome XML XSLT toolkit http://xmlsoft.org/ http://veillard.com/ | virtualization library http://libvirt.org/
participants (5)
-
Daniel P. Berrange -
Daniel Veillard -
Dave Allan -
Doug Goldstein -
Michal Privoznik