(20:53:06) TheSheep: Delfyn: instead of using those messages, I'd just rise an exception
(20:53:18) TheSheep: Delfyn: and then catch it at the end
(20:54:50) TheSheep: Delfyn: you can put the message in the exception object, so you don't even need globals then
(20:55:38) Me: ok ... i didn't really understand python.org's explanation of try/except ...
(20:55:59) Me: if i raise and error will the remaining code be executed or will it jump straight to the end?
(20:56:08) Me: and=an
(20:56:08) TheSheep: Delfyn: it will jump
(20:56:17) Me: ah ... ok ...
(20:56:32) TheSheep: Delfyn: it will also keep returning from funtions until the exception is caught
(20:56:47) Me: err ... ?
(20:56:59) TheSheep: suppose you have something like this:
(20:57:11) Me: you mean that error *must* be explicity handled?
(20:57:32) TheSheep: try:  some_function(foo); print 'hello'; except SomeError: print "oops"
(20:57:56) TheSheep: and you rise an exception SomeError inside some_function, but you don't catch it
(20:58:28) TheSheep: then it will skip all the remaining code in some_function, skip the 'print "hello"', and stop where it is caught
(20:58:35) TheSheep: then 'oops' will be printed
(20:58:56) TheSheep: and the execution will resume from after the except block
(20:59:01) Me: ahh ... okay, so the exception name space goes across function call boundaries
(20:59:20) Me: and "SomeError" is just free text?
(20:59:39) TheSheep: no, you want to make the exception itself a separate class
(20:59:59) Me: why? 
(21:00:15) TheSheep: class SomeError: def __init__(self, message=""): self.message = message
(21:00:29) TheSheep: and then do:  except SomeError, e: print e.message
(21:00:52) TheSheep: and when you raise, it, do:  raise SomeError("oops!")
(21:01:05) Me: okay, stop there ... 
(21:01:19) Me: i didn't really understand that but I've copied it and will try it :-)
(21:01:31) TheSheep: you need to insert newlines and indetation
(21:01:37) Me: clear