The pyxb API doesn't cope correctly with UTF-8 encoded characters such as 'Sign of Leser-Tr\xc3\xa9lat'. Assigning this data to an element, an attribute or using it in a constructor all result in the same error.
We can proposed a fix that takes care of the first case:
instance = bar()
instance.e = 'Sign of Leser-Tr\xc3\xa9lat'
But have no solutions to the other two situations.
(The proposed fix is in basis.py at line ~286
if str == value_type:
A test case has been attached.