API¶
Trafaret¶
Base class for checkers. Use it to create new checkers. In derived classes you need to implement _check or _check_val methods. _check_val must return a value, _check must return None on success.
You can implement converter method if you want to convert value somehow, that said you prolly want to make it possible for the developer to apply their own converters to raw data. This used to return strings instead of re.Match object in String trafaret.
Subclassing¶
For your own trafaret creation you need to subclass Trafaret
class
and implement check_value
or check_and_return
methods. check_value
can return nothing on success,
check_and_return
must return value. In case of failure you need to
raise DataError
. You can use self._failure
shortcut function
to do this. Check library code for samples.