Python while loop

A while loop in Python repeatedly executes a block of code as long as a specified condition is True. The loop will stop when the condition becomes False.

loop’s body is executed repeatedly while the test at the top is true; if the test is false to begin with, the body never runs.

Syntax:

while condition:
    # Code to execute repeatedly

Example 1: Basic while loop

count = 0
while count < 4:
    print(count)
    count = counter + 1  # Increment the counter

Output:

0 1 2 3

In this example, the loop continues until count is no longer less than 4.

Example 2: while loop with break

You can use the break statement to exit the loop early.

i = 0
while i < 5:
    print(i)
    if i == 3:
        break  # Exit the loop when i is 3
    i += 1

Output:

0 1 2

Example 3: while loop with else

Similar to a for loop, you can use an else clause with a while loop. The else the block will run if the loop completes without encountering a break.

i = 0
while i < 3:
    print(i)
    i += 1
else:
    print("Loop finished!")

Output:

0
1
2

Example 4: Infinite loop

A while loop can become an infinite loop if the condition never becomes False.

while True:
    print("This is an infinite loop!")
    break  # Use a break to avoid an actual infinite loop

Without the break, this would print endlessly. Infinite loops are commonly used when waiting for specific conditions to occur.