list.count() — Python Technical Interview Questions & Answers

list.count()

list.count()

  • list.count() works on a list. Lists can change. Many methods update the same list (append, pop, sort, insert) instead of returning a new one.
  • list.count() — output: 2. How many times 2 appears.
  • Trap for list.count(): append([1, 2]) nests a list. extend([1, 2]) adds 1 and 2. sort vs sorted is a viva favourite.
  index →  0       1       2
  list  → [Asha,  Ravi,  Neha]

Technical Interview Tip: In place or new list? Say it first, then one example.

Code Examples for list.count()

Example

# list.count()
print([1, 2, 2, 3].count(2))

list.count() — output: 2. How many times 2 appears.

How to Explain list.count() to an Interviewer

Explain list.count() as if you are teaching a junior — definition, then one tiny script.

list.count() changes or reads a list. list.count() — many list methods are in place.

What does the example print, and why?

list

What mistake do freshers make with list.count()?

list.count() — sort vs sorted, in place vs new list.