while Loop in Python — Python Technical Interview Questions & Answers

while Loop in Python

while Loop in Python

  • while checks a condition first, then runs the body, then checks again. while i <= 3: print(i); i += 1. If you forget i += 1, it never ends. If i starts at 10 and the condition is i <= 3, the body runs zero times. That “maybe zero” fact is an MCQ favourite.
  • Use while when you don’t know the count: read lines until empty, retry until success. for is cleaner when you already have a list. Contrast them in one sentence each.
  • while Loop in Python — output: 1 then 2 then 3. When i becomes 4, loop stops.
  i = 1
    │ i <= 3 ?
    ▼ yes
  print(i); i += 1
    │
    ▼ i = 4 → stop

Technical Interview Tip: Counter while i <= 3 + what if i starts too big.

Code Examples for while Loop in Python

Example

# while
i = 1
while i <= 3:
    print(i)
    i += 1

while Loop in Python — output: 1 then 2 then 3. When i becomes 4, loop stops.

How to Explain while Loop in Python to an Interviewer

Explain while Loop as if you are teaching a junior — definition, then one tiny script.

Repeat while condition is true. Update inside the body.

What does the example print, and why?

while Loop in Python — output: 1 then 2 then 3

What mistake do freshers make with while Loop?

Forget update → infinite loop.