It appears that wfrog does not support yet python 2.7. In the meantime, you 
will have to install python 2.6 alongside

Confirmed.
Here's the workaround for the time being.

1) Install python 2.6
$ sudo apt-get install python2.6
2) Change the default python to 2.6
$ ls -l /usr/bin/python*
lrwxrwxrwx 1 root root       9 2011-04-28 21:18 /usr/bin/python -> python2.7
-rwxr-xr-x 1 root root 2333224 2011-03-25 21:32 /usr/bin/python2.6
-rwxr-xr-x 1 root root 2375356 2011-04-11 22:14 /usr/bin/python2.7
$ sudo rm /usr/bin/python
$ sudo ln -s /usr/bin/python2.6 /usr/bin/python
$ ls -l /usr/bin/python*
lrwxrwxrwx 1 root root      18 2011-05-09 11:11 /usr/bin/python -> 
/usr/bin/python2.6
-rwxr-xr-x 1 root root 2333224 2011-03-25 21:32 /usr/bin/python2.6
-rwxr-xr-x 1 root root 2375356 2011-04-11 22:14 /usr/bin/python2.7
$

After these steps all work as before.

Note, that this makes a system-wide change. If python2.7 is required somewhere, 
it probably brakes after this change.

Thanks for the help.

The workaround works indeed, but on ubuntu 11.04 it will instead break the 
Ubuntu Update Manager (which needs link to python2.7).

Hi, 
my solution Elecsa Astrotouch 6975 ubuntu 11.10 x86_64 3.0.0-12-generic

get pywws
test if pywws Test station py works (if not, comment the check magic number in 
pywws/WeatherStation.py)
sudo python2.6 setup.py install
install wfrog deb package
edit /usr/bin/wfrog to use python2.6 (first line) instead of python

seems to work
thx

Hi,
This issue got worse with Ubuntu 12.04, since python2.6 package is not included 
in the distribution any more and wfrog still does not support python2.7 or 
python3, which now are available.
I have yet to find a workaround.

I you encourage to prioritize this issue.

Issue 114 has been merged into this issue.

Found this guide to install python 2.6 on ubuntu 12.04
https://singhgurjot.wordpress.com/2012/07/10/how-to-install-python-2-6-in-ubuntu
-12-04/

The problem is due to a problem recovetin

I've found a workaround for this issue. 

In the file ./wfrog-0.8.2/wfcommon/config/fileloghandler.yaml

If you comment out the RotatingFileHandler declaration and replace it with a 
NullHandler declaration you should be able to get wfrog to start.

Post change, the file should appear as follows:

#handler: !!python/object/new:logging.handlers.RotatingFileHandler
handler: !!python/object/new:logging.NullHandler
    kwds:
        filename: ${filename}
        maxBytes: 262144
        backupCount: 3

This obviously has ramifications for the way wfrog does logging, but it should 
at least get you running on Python 2.7.3.

The problem is related with the way yaml instantiates the objects. For some 
reason it is not doing it the right way on python 2.7. I've created an issue in 
python to check for this problem: http://bugs.python.org/issue15616

From python 2.6 to python 2.7 logging classes switched from old style to new 
style classes. This change could have triggered this issue. I've created an 
issue in PyYaml (http://pyyaml.org/ticket/283).

Since it is not clear how can be solved the problem instantiating
handlers via yaml I've implemented a workaround: wfrog uses by
default a RotatingFileHandler without using yaml. 

We assume that this fits the needs of most users and allow wfrog
to run out of the box in all versions of python. When a solution is
found for yaml we will reverse the workaround.

I leave the issue open, waiting for final solution

Hi, I think I've just struck this issue and was wondering if there's any 
updates about a permanent fix?

The pyyaml ticket is still open ... just use the latest svn version and that 
should solve the problem. We ought to create a new version of wfrog with these 
changes!!

Its been a while since I've had a chance to attack this problem again...

First time around I used the workaround proposed by Quigle which got wfrog to 
load, however I could never get the dashboard to load, it constantly threw 500 
(Internal Server) errors. However I think that was a separate issue due to 
trying a custom configuration (I need an external database because I have extra 
sensors)

Second time around I installed the base .deb package, then downloaded the 
latest svn build and overwrote the wfcommon, wflogger, wfrenderer and wfdriver 
folders with the svn folders. Probably not the "correct" way to install them, 
but it appears to work, I have my dashboard... Now to break it trying for a 
customisation...

I have an alternative workaround which worked for me on Ubuntu 12.04 with 
python 2.7:

In the file wfcommon/config/fileloghandler.yaml, change 'new' to 'apply' in the 
line

  handler: !!python/object/new:logging.handlers.RotatingFileHandler

so you end up with:

handler: !!python/object/apply:logging.handlers.RotatingFileHandler
    kwds:
        filename: ${filename}
        maxBytes: 262144
        backupCount: 3


This *should* work with earlier versions of python too, but I haven't tested it.

Andy's workaround worked also for me, Ubuntu 13.04 and wfrog 0.8.2. Required no 
other tweek, installed wfrog, ran wfrog, activated simulation settings and 
started wfrog. Without the tweek I got the same error as mentioned above, after 
having entered all simulation settings.

Andy's workaround works also for me ! Ubtuntu_13.04 and wfrog_0.8.2 configured 
as " random-simulator ".

[deleted comment]

Andy workaround eventually worked for me after clean ubuntu server 14.04 
installation

but to be able to access my WR200 station I had to load module usbhid