On Mon, Jun 26, 2017 at 2:41 PM, Nick Coghlan <ncoghlan@gmail.com> wrote:
If we wanted to allow that to be expressed literally, we could probably special case the "while not break" keyword sequence as a do loop:
while not break: # Setup if condition: break # Loop continuation
That more explicit declaration of intent ("The code in the loop body will conditionally break out of this loop") would allow a couple of things:
- the compiler could warn that an else clause attached to such a loop will never execute (technically it could do that for any expression that resolves to `True` as a constant) - code linters could check the loop body for a break statement and complain if they didn't see one
Logically, it's exactly the same as writing "while True:", but whereas that spelling suggests "infinite loop", the "while not break:" spelling would more directly suggest "terminated inside the loop body via a break statement"
What I like doing is writing these loops with a string literal as the "condition". It compiles to the same bytecode as 'while True' does, and then you can say what you like in the string. (An empty string would be like 'while False', but there's no point doing that anyway.) So, for example: while "password not correct": password = input('Password:') if password == secret_password: break print('Invalid password, try again!') ChrisA