[AG-TECH] Developers - python2.5 vs 2.6 (was: How to differentiate ...)

Christoph Willing c.willing at uq.edu.au
Tue May 18 08:46:53 CDT 2010


On 18/05/2010, at 10:44 PM, Christoph Willing wrote:

>
> On 18/05/2010, at 7:12 AM, Jesus Cea Oliva wrote:
>
>> Thanks Christoph again for your responses, that, always helps ;).
>>
>> It's possible install python 2.5 on newer Linux distributions and  
>> do something for Access Grid "take" the python 2.5 modules? We have  
>> a server with Ubuntu Karmic and reinstall the system is not  
>> possible due to there are many programs installed for others  
>> purposes.
>>
>
> Although 2.6 is the default python on karmic, the official Ubuntu  
> repos have versions 2.4 and 2.5 available too (even 3.1 actually).  
> They can be installed at the same time. Applications can then call  
> any of them explicitly e.g. application script could start with #!/ 
> usr/bin/python2.6 or #!/usr/bin/python2.5 etc. Another mechanism to  
> choose between them is to add python to the "alternatives" framework  
> and then select the version you want to be the default using "update- 
> alternatives".
>
> So I think the answer is yes - you may be able to run python 2.5 on  
> your server alongside 2.6. The AccessGrid applications all begin  
> with #!/usr/bin/python so they should use whichever python is set as  
> the default with update-alternatives.


I just tried this myself on a karmic system which already has  
python2.6 - first install python2.5 using apt-get or synaptic etc.
Then add both versions to the alternatives framework:
     sudo update-alternatives --install /usr/bin/python python /usr/ 
bin/python2.5 20
     sudo update-alternatives --install /usr/bin/python python /usr/ 
bin/python2.6 10

Because 2.5 was given a higher priority (20 compared with 10)  
python2.5 will now be the default.

Now run a VenueServer and VenueClient - the data upload works perfectly.

Just to confirm 2.6 bad behaviour, run:
     sudo update-alternatives --configure python
and select python2.6 to be the new default. Now run a new VenueServer  
and VenueClient - the data upload is broken.


Unfortunately Lucid seems to have only pythons 2.6 and 3.1 so can't do  
the same comparison there.


chris


> To protect the other services your server is providing, you would  
> want to check that those services are able to run OK in the  
> different python environment.
>
>
>> Thanks again for your help about differenciate rolles, I'll try as  
>> soon as possible :).
>>
>> It's possible to "work" with the Server? I would like to have a DB  
>> (sqlite?) for manage Tests (tests, students, etc) and it should be  
>> on the Server due to concurrency issues. So, the shared application  
>> should send the data to the server and, then, it insert this data  
>> (or manipulate) to the DB.
>>
>
>
> There is a sqlite3 module for python so your idea would probably  
> work OK. See:
>    http://docs.python.org/library/sqlite3.html
>
>
> chris
>
>
>> El dia 17 may 2010 13:10, Christoph Willing <c.willing at uq.edu.au>  
>> escribió:
>> On 17/05/2010, at 6:41 AM, Jesus Cea Oliva wrote:
>>
>> Hi list!
>>
>> Firstly, any news about file uploading and sent/recive events? :P.  
>> I have a virtual machine with Fedora 10 and there works all fine,  
>> so, I'm working with this machine now.
>>
>> The fact that Fedora 10 uses python2.5 (and works correctly)  
>> supports someone's idea that this is problem is related to the  
>> python version being used; so far, all known non-working cases use  
>> python2.6.
>>
>>
>> Well, we are doing some Shared Applications for our project, like a  
>> PDF Viewer or, now, I'm developing an application for create  
>> evaluation tests and, later, do them.
>>
>> I need to differenciate two "roles" for my applications: the  
>> "creator", I mean, the participant that "invokes" a Shared  
>> Application; and the "viewer" or something like this, I mean, the  
>> participant that receive the invitation of a Shared Application.  
>> (sorry for the roles name xD)
>>
>> I would like to show differents windows for this roles. For  
>> example, on the evaluation tests designer; the application shows to  
>> the creator (a teacher, for example) a form to design a evaluation  
>> test. However, if the participant is the "viewer" (a student, for  
>> example), the application shows a evaluation test designed.
>>
>> On others Shared application, I would like to differenciate this  
>> roles. It this possible?. How?
>>
>> I suggest you have a look at AccessGrid/AppMonitor.py - it shows  
>> how to join a Shared App., obtain its state and then its  
>> description. This description seems to include the name of whoever  
>> started the app - as is shown if you right click->Open Monitor on  
>> any shared app. In your applications, if your own profile's name  
>> matches that of the app's creator then you would consider yourself  
>> the teacher, otherwise a student.
>>
>>
>> chris
>>
>>
>> Christoph Willing +61 7 3365 8316
>> QCIF Access Grid Manager
>> University of Queensland
>>
>>
>
> Christoph Willing                       +61 7 3365 8316
> QCIF Access Grid Manager
> University of Queensland
>

Christoph Willing                       +61 7 3365 8316
QCIF Access Grid Manager
University of Queensland



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