CODEWITHSUNDEEP
enthought
jim vickroy
jim vickroy

Reputation: 142

How to disable traits notification handler traceback messages?

How can I disable presentation of traits notification handler traceback messages in a console window? An example is:

from   traits.api import HasPrivateTraits, Property, String, TraitError
from   traits.api import cached_property, on_trait_change

class Equipment (HasPrivateTraits):
    manufacturer = String   (minlen=2,maxlen=50)
    model        = String   (minlen=2,maxlen=20)
    _id          = Property (depends_on='manufacturer, model')
    @cached_property
    def _get__id (self):
        return hash ((hash(self.manufacturer), hash(self.model)))
    @on_trait_change ('manufacturer, model')
    def check_manufacturer_model (self):
        if self.manufacturer.upper() == self.model.upper():
            raise TraitError ('manufacturer and model are the same')

if __name__ == '__main__':
    ## http://docs.enthought.com/traits/traits_user_manual/debugging.html
    from traits.api import push_exception_handler
    push_exception_handler(reraise_exceptions=True)
    try:
        Equipment (manufacturer='foo', model='foo')
    except TraitError as result:
        assert str(result) == 'manufacturer and model are the same'
    else:
        print ('LOGIC ERROR: <<< 01 >>>')

which produces the following output (I want to prevent):

Exception occurred in traits notification handler.
Please check the log file for details.
Exception occurred in traits notification handler for object: <__main__.Equipment object at 0x00000275C8AE0468>, trait: model, old value: , new value: foo
Traceback (most recent call last):
  File "C:\Users\jgv\AppData\Local\Programs\Python\Python36\lib\site-packages\traits\trait_notifiers.py", line 519, in _dispatch_change_event
    self.dispatch( handler, *args )
  File "C:\Users\jgv\AppData\Local\Programs\Python\Python36\lib\site-packages\traits\trait_notifiers.py", line 482, in dispatch
    handler( *args )
  File "testit.py", line 18, in check_manufacturer_model
    raise TraitError ('manufacturer and model are the same ({})'.format(self.model))
traits.trait_errors.TraitError: manufacturer and model are the same

My system is Python 3.6.0, traits 4.6.0, and Microsoft Windows 10.

Thanks, -jim

Upvotes: 2

Views: 412

Answers (1)

Robert Kern
Robert Kern

Reputation: 13430

You need to provide push_exception_handler() with a dummy exception handler function to override the current handler function.

push_exception_handler(lambda *args: None, reraise_exceptions=True)

Just passing reraise_exceptions=True will let the current handler function do whatever it normally does, but then reraise after it has finished.

Upvotes: 3

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