list of custom defined exceptions. How to create such a list?

Question

Is there any way where we can store the user defined exceptions (our customized exceptions) in a list? So that if any other exception occurs, which is not in list.. the program should simply be aborted.

Answer 1

A single except can have multiple errors, custom or otherwise:

>>> class MyError(Exception):
    pass

>>> try:
    int("foo") # will raise ValueError
except (MyError, ValueError):
    print "Thought this might happen"
except Exception:
    print "Didn't think that would happen"


Thought this might happen
>>> try:
    1 / 0 # will raise ZeroDivisionError
except (MyError, ValueError):
    print "Thought this might happen"
except Exception:
    print "Didn't think that would happen"


Didn't think that would happen

Answer 2

The usual way to do this is with an exception hierarchy.

class OurError(Exception):
    pass

class PotatoError(OurError):
    pass

class SpamError(OurError):
    pass

# As many more as you like ...

Then you just catch OurError in the except block, rather than trying to catch a tuple of them or having multiple except blocks.

---

Of course, nothing actually prevents you from storing them in a list like you mention:

>>> our_exceptions = [ValueError, TypeError]
>>> try:
...    1 + 'a'
... except tuple(our_exceptions) as the_error:
...    print 'caught {}'.format(the_error.__class__)
...     
caught <type 'exceptions.TypeError'>