Python Set Methods — Python Technical Interview Questions & Answers

Python Set Methods

Python Set Methods

  • Set methods add, remove, or do set algebra. add(x) inserts one. update(...) adds many. remove(x) errors if x is missing. discard(x) stays quiet. pop() removes an arbitrary item. union / intersection / difference / symmetric_difference match | & - ^ . issubset / issuperset / isdisjoint test relationships.
  • MCQ: remove vs discard. remove(99) on a set without 99 → KeyError. discard(99) does nothing. Say that pair first.
  • Python Set Methods — output: {1, 2, 3}. discard(9) does nothing — no crash.
  {1, 2, 2, 3}
         │ unique
         ▼
      {1, 2, 3}

Technical Interview Tip: remove raises; discard stays quiet.

Code Examples for Python Set Methods

Example

# Set methods
s = {1, 2}
s.add(3)
s.discard(9)
print(s)

Python Set Methods — output: {1, 2, 3}. discard(9) does nothing — no crash.

How to Explain Python Set Methods to an Interviewer

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

Add / update Remove vs discard

What does the example print, and why?

Python Set Methods — output: {1, 2, 3}

What mistake do freshers make with Set Methods?

Union / intersection