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Why avoid while loops?

I am trying to learn Python by following Learn Python The Hard Way and as I have progressed along I found it mentioned on the site that,

Use a while-loop only to loop forever, and that means probably never. This only applies to Python, other languages are different.

Now I am basically a Java developer and this got me wondering as to why while should be avoided in python although it is widely used in Java. I haven’t been able to find any answer on the internet.

Answer 1

That statement is highly subjective and I am not sure I’d agree with it. It is easy to have an infinite loop using while in Python:

  while True:
       # do stuff

Perhaps the author was comparing this with C where it is also easy to have an infinite loop with for:

  for(;;)
      /* do stuff */

No such corresponding construct really exists for Python.

Having said there there are plenty of instances where an infinite loop is useful (in any language) – think event loops, or where the loop control can be simplified by having an infinite loop and only certain conditions causing a break.

Frequently you’ll be processing sequences such as list and strings and the use of a for-loop will be a natural fit, but I’d not dismiss the while-loop simply because of that.