while loops are a special type of loop in Python. Instead of running just once when a condition is met, like an if statement, they run forever until a condition is no longer met.
while loops usually need to be accompanied by an always changing sentinel value.
>>> counter = 0
>>> max = 4
>>>
>>> while counter < max:
... print(f"The count is: {counter}")
... counter = counter + 1
...
The count is: 0
The count is: 1
The count is: 2
The count is: 3
Our loop will run forever if we forget to update the sentinel value. Press Ctrl-C to exit the infinite loop.
# Warning: don't copy and paste this example.
>>> counter = 0
>>> max = 4
>>> while counter < max:
... print(f"The count is: {counter}")
...
# What happens if we don't update counter?
The count is: 0
The count is: 0
The count is: 0
The count is: 0
# An infinite loop repeated until we hit Ctrl-C
The count ^CTraceback (most recent call last):
File "<stdin>", line 2, in <module>
KeyboardInterrupt