[Tutor] Language truce

[Remco Gerlich]

On  0, D-Man <dsh8290@rit.edu> wrote:
> On Thu, Jun 28, 2001 at 02:20:58PM -0700, Danny Yoo wrote:
> | One reason that 'for/in' might be preferred is because we are guaranteed
> | that the loop will always terminate: there can only be a finite number of
> | elements in a list.  That's one big advantage of a loop construct that
> | goes along elements --- theoretically, we'll never get into infinite
> | loops.
> 
> Almost.
> 
> l = range( 1 )
> for i in l :
>     print l
>     l.append( i+1 )
> 
> Don't do this!  It's just as bad in C or any other language --
> mutating a collection while iterating over it is just a bad idea.

Or even:

class InfiniteList:
   def __getitem__(self, i):
      return i

for i in InfiniteList():
   print i
   
(well, it'll end when i doesn't fit into an integer anymore)

-- 
Remco Gerlich