Why is this python loop going to infinity?

Question

a = 10
counter = 0
condition = (counter<3)
while condition:
    a= a +1
    print (a)
    counter = counter + 1

imagedescription

Answer 1

Because condition is calculated once and never is updated. So, condition is always True even though counter is updated.

Answer 2

In the line

condition = (counter<3)

Python executes the comparison on the right and assigns it to "condition" on the left. This happens once before the loop and condition is always True. You seem to be under the impression that condition is a function, but it's not. Its right hand side is only run once, before the loop begins.

The easy fix is to do the operation in the loop condition so that it is re-executed every time.

a = 10
counter = 0
while counter < 3:
    a= a +1
    print (a)
    counter = counter + 1

Answer 3

Your condition never changes inside the loop. You must update your condition inside of the loop looking like this:

a = 10
counter = 0
condition = counter < 3
while condition:
    a= a +1
    print (a)
    counter = counter + 1
    condition = counter < 3

But this violates the DRY (don't repeat yourself) principle. I would completely remove your condition variable and implement your condition with your logic like so:

a = 10
counter = 0
while counter < 3:
    a= a +1
    print (a)
    counter = counter + 1

Answer 4

When you initially assigned condition it was given the value 'True'. Its value doesn't change when you increase counter. A better method would be:

a = 10
counter = 0
while counter < 3:
    a = a + 1
    print(a)
    counter = counter + 1