Entiendo que te refieres a lo siguiente,
Tras comentar el except:

Ejecuto:
(tryton401) manuel@localhost:~/.tryton/t401$ python 
trytond/bin/trytond-admin -c trytond.conf -d dv4 -u default_value

Obtengo:
Traceback (most recent call last):
  File "trytond/bin/trytond-admin", line 21, in <module>
    admin.run(options)
  File "/home/manuel/.tryton/t401/trytond/trytond/admin.py", line 48, in run
    Pool(db_name).init(update=options.update, lang=lang)
  File "/home/manuel/.tryton/t401/trytond/trytond/pool.py", line 144, in 
init
    self.start()
  File "/home/manuel/.tryton/t401/trytond/trytond/pool.py", line 97, in 
start
    register_classes()
  File "/home/manuel/.tryton/t401/trytond/trytond/modules/__init__.py", 
line 362, in register_classes
    mod_file, pathname, description)
  File 
"/home/manuel/.tryton/t401/trytond/trytond/modules/default_value/__init__.py", 
line 5, in <module>
    from .default_value import *



Responder a