[파이썬] - collections 모듈 ( 개수와 최빈값 )

🔎 Counter( ) : 요소의 개수

Counter( 리스트 )

from collections import Counter

arr1 = [1, 1, 2, 3, 3, 3]
arr2 = [3, 3, 3, 3, 3, 3]

print(Counter(arr1))
# 출력: Counter({3: 3, 1: 2, 2: 1})

print(Counter(arr1) - Counter(arr2))
# 출력: Counter({1: 2, 2: 1})

---

import collections

arr1 = [1, 1, 2, 3, 3, 3]
arr2 = [3, 3, 3, 3, 3, 3]

print(collections.Counter(arr1))
# 출력: Counter({3: 3, 1: 2, 2: 1})

print(collections.Counter(arr1) - collections.Counter(arr2))
# 출력: Counter({1: 2, 2: 1})

🔎 most_common( ) : 최빈값

Counter( 리스트 ) . most_common( n ) : 리스트에서 최빈값 n개 반환

from collections import Counter

arr = [1, 1, 2, 3, 3, 3]

print(Counter(arr).most_common(2))	# 최빈값 2개 반환
# 출력: [(3, 3), (1, 2)]

---

import collections

arr = [1, 1, 2, 3, 3, 3]

print(collections.Counter(arr).most_common(2))	# 최빈값 2개 반환
# 출력: [(3, 3), (1, 2)]