I do like the else clause with for loops. However most people are not familiar with it, and also `else:` as a keyword is confusing. I always remember it as `no break:`.
That's still confusing though. The problem here is that `else` is semantically attached to `break`, but syntactically attached to the body of the loop. The latter makes it look like it executes if the loop body didn't, if you interpret it in the most straightforward way.
IMO a better design would be to have a block that always executes at the end of the loop - there's even a reasonable keyword for it, `finally` - but gets a boolean flag indicating whether there was a break or not:
for server in servers:
if server.check_availability():
primary_server = server
break
finally did_break:
if not did_break:
primary_server = backup_server
Or better yet, make `break` take an optional argument (which defaults to `True` if unspecified), and that's what you get in `finally`. So this could be written:
for server in servers:
if server.check_availability():
break server
finally server:
primary_server = server if server is not None else backup_server
