Python) itertools

combinations - 조합

from itertools import combinations

sample_list = [1,2,3,4,5]

combin_list = [i for i in combinations(sample_list,3)]

결과: [(1, 2, 3), (1, 2, 4), (1, 2, 5), (1, 3, 4), (1, 3, 5) ...]

자기 자신도 들어가야한다면 combinations_with_replacement(it,r) 사용하기

permutations - 순열

from itertools import permutations

sample_list = [1,2,3,4,5]

permut_list = [i for i in permutations(sample_list,2)]

결과: [(1, 2), (1, 3), (1, 4), (1, 5), (2, 1), (2, 3), (2, 4) ...]

product - 데카르트 곱

from itertools import product

sample1 = [1,2]
sample2 = [3,4]

# default: repeat=1
pd_list = [i for i in product(sample1,sample2,repeat=1)]  
 

결과: [(1,3),(1,4),(2,3),(2,4)]