Python while Loop

1. Basic while Loop

count = 1

while count <= 5:
    print(count)
    count += 1

Executes repeatedly as long as the condition evaluates to True.

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2. Decrementing Counter in while Loop

number = 5

while number > 0:
    print(number)
    number -= 1

Commonly used for countdown logic.

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3. Using while with User Input

user_input = ""

while user_input != "exit":
    user_input = input("Type 'exit' to stop: ")

Loop continues until a specific input condition is met.

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4. Infinite while Loop

while True:
    print("Running...")

Creates an endless loop unless interrupted with break.

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5. Breaking a while Loop

count = 0

while True:
    if count == 3:
        break
    print(count)
    count += 1

break terminates the loop immediately.

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6. Using continue in while Loop

number = 0

while number < 5:
    number += 1
    if number == 3:
        continue
    print(number)

Skips the current iteration and proceeds to the next cycle.

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7. while Loop with else Clause

x = 0

while x < 3:
    print(x)
    x += 1
else:
    print("Loop completed normally")

The else block runs if the loop ends without encountering break.

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8. Simulating do-while Loop Behavior

count = 0

while True:
    print("Executing at least once")
    count += 1
    if count == 3:
        break

Python does not have a native do-while, but this pattern replicates it.

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9. Nested while Loops

i = 1

while i <= 3:
    j = 1
    while j <= 2:
        print(f"i={i}, j={j}")
        j += 1
    i += 1

A while loop inside another while loop.

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10. Using while for Input Validation

age = -1

while age < 0:
    age = int(input("Enter a positive age: "))

print("Valid age entered:", age)

Ensures user input meets required constraints before proceeding.

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