collections module — Python Technical Interview Questions & Answers

collections module

collections module

  • collections adds deque, Counter, namedtuple, defaultdict. deque is a fast queue. Counter counts items. namedtuple is a tiny immutable record.
  • from collections import Counter; Counter("Asha") shows letter counts. That one line is a real example.
  • collections module — output: Counter of letters in Asha, then deque [0, 1, 2].

Technical Interview Tip: Name three collections types + one use each.

Code Examples for collections module

Example

# collections module
from collections import Counter, deque
print(Counter("Asha"))
q = deque([1, 2])
q.appendleft(0)
print(list(q))

collections module — output: Counter of letters in Asha, then deque [0, 1, 2].

How to Explain collections module to an Interviewer

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

Collections adds deque, Counter, namedtuple, defaultdict. From collections import Counter; Counter("Asha") shows letter counts.

What does the example print, and why?

collections module — output: Counter of letters in Asha, then deque [0, 1, 2]

What mistake do freshers make with collections module?

Collections module — output: Counter of letters in Asha, then deque [0, 1, 2].