A single, general looping construct? (was: why no "do : until"?)

[Rainer Deyke]

"Steve Holden" <sholden at holdenweb.com> wrote in message
news:HxL66.2499$24.24441 at e420r-atl2.usenetserver.com...
> Also, in both your original example and my extension, the final "while"
> statement has a condition which isn't really a Boolean. You appear to mean
> "as long as a particular exception has not been raised", but exceptions
> don't really work like that. You would end up having to clear a flag
before
> the loop, and set it when the exception occurs:
>
> flag = 0
> try:
>   filename = raw_input('Data file: ')
>   f = open(filename, 'r')
>   # Process the file
> except IOError:
>   print "Could not open file", filename
>   flag = 1
> while not flag
>
> which does not seem to be a real improvement over
>
> flag = 0
> while not flag:
>   try:
>     filename = raw_input('Data file: ')
>     f = open(filename, 'r')
>     # Process the file
>   except IOError:
>     print "Could not open file", filename
>     flag = 1

Even better:

try:
  while 1:
    filename = raw_input('Data file: ')
    f = open(filename, 'r')
    # Process the file
except IOError:
  print "Could not open file", filename


--
Rainer Deyke (root at rainerdeyke.com)
Shareware computer games           -           http://rainerdeyke.com
"In ihren Reihen zu stehen heisst unter Feinden zu kaempfen" - Abigor