Linear Search in Python — Python Technical Interview Questions & Answers

Linear Search in Python

Linear Search in Python

  • Linear search checks each item from start to end until it finds the target. Works on unsorted lists. Worst case you look at all n items — O(n). Code is a for-loop and an if. Acceptable on small lists or when data is not sorted. On a huge sorted list, binary search is the better story.
  • Trace [4, 1, 3, 2] looking for 3: check 4, check 1, check 3 — found. Say O(n) honestly. Don’t claim it is “always slow” — for n=10 it is fine.
  • Linear Search in Python — output: 1. 90 is at index 1. If missing, found stays -1.

Technical Interview Tip: When linear search is acceptable.

Code Examples for Linear Search in Python

Example

# Linear search
marks = [70, 90, 80]
key = 90
found = -1
for i, x in enumerate(marks):
    if x == key:
        found = i
        break
print(found)

Linear Search in Python — output: 1. 90 is at index 1. If missing, found stays -1.

How to Explain Linear Search in Python to an Interviewer

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

Scan one by one. Works unsorted. O(n).

What does the example print, and why?

Linear Search in Python — output: 1

What mistake do freshers make with Linear Search?

Easy to code.