Exceptions


Python Exception mechanism similar to Java and C++
try:
    foo(x,y)
    z = spam / x
except ZeroDivisionError:
    print "Can't Divide by Zero"
except FooError, data:
    print "Foo raised an error", data
except:
    print "Something went wrong"
else:
    print "It worked!"

User code can raise an error
raise FooError, "First argument must be >= 0"