While Loop in Python

A while loop in Python is used to execute a block of code repeatedly until a specified condition becomes false.

While loops are very useful when the number of iterations is not fixed and depends on a condition.

Important: Be careful while using while loops. If the condition never becomes false, the loop will run forever and create an infinite loop.

Why Use While Loop?

• To execute code repeatedly
• Useful when iteration count is unknown
• Helps automate repetitive tasks
• Widely used in automation frameworks
• Useful in menu-driven programs

Syntax of While Loop

while condition:
    # code block

The loop continues until the condition becomes false.

Simple Example of While Loop

count = 1

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

Output

1
2
3
4
5

Understanding the Flow

1. Initialize variable count = 1
2. Check condition count <= 5
3. Execute print statement
4. Increase count value
5. Loop continues until condition becomes false

Infinite While Loop Example

while True:
    print("Way2Testing")

The above loop will run forever because the condition is always true.

Using Break Statement

The break statement is used to stop the loop immediately.

count = 1

while True:
    print(count)

    if count == 5:
        break

    count = count + 1

Output

1
2
3
4
5

Using Continue Statement

The continue statement skips the current iteration and moves to the next iteration.

count = 0

while count < 5:

    count = count + 1

    if count == 3:
        continue

    print(count)

Output

1
2
4
5

While Loop with User Input

password = ""

while password != "admin123":
    password = input("Enter Password: ")

print("Login Successful")

Nested While Loop Example

i = 1

while i <= 3:

    j = 1

    while j <= 2:
        print("i =", i, "j =", j)
        j = j + 1

    i = i + 1

Output

i = 1 j = 1
i = 1 j = 2
i = 2 j = 1
i = 2 j = 2
i = 3 j = 1
i = 3 j = 2

Real-Time Example for Automation Testers

Suppose you want to wait until an API returns status code 200.

status = 500

while status != 200:

    print("Retrying API Call...")

    # API call logic here

    status = 200

print("API Executed Successfully")

Output

Retrying API Call...
API Executed Successfully

Difference Between For Loop and While Loop

For Loop	While Loop
Used when iteration count is fixed	Used when iteration count is unknown
More readable for collections	Better for condition-based execution
Less risk of infinite loops	Higher risk of infinite loops
Mostly used with lists, tuples, ranges	Mostly used with conditions

Common Mistakes in While Loop

• Forgetting to update loop variable
• Creating infinite loops accidentally
• Wrong indentation
• Incorrect loop condition

Best Practices

• Always make sure condition eventually becomes false
• Use meaningful variable names
• Avoid unnecessary infinite loops
• Use break statement carefully

Conclusion

The while loop is one of the most important looping concepts in Python. It helps execute code repeatedly based on conditions and is widely used in real-time applications, automation frameworks, API retries, and menu-driven programs.

Understanding while loops properly will make your Python programming much stronger.

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Practice Exercise:
Create a while loop program that prints numbers from 1 to 10 and skips number 5 using continue statement.

Happy Learning With Way2Testing