itertools: 효율적인 looping을 위한 iterator를 만드는 함수
import itertools
[ 문자열에서 필요에 맞는 결합을 생성하는 방법 ]
pairwise()
pairwise('ABCDEFG')
#result: AB BC CD DE EF FG
product()
from itertools import product as pd
product('ABCD', repeat=2)
#result: AA AB AC AD BA BB BC BD CA CB CC CD DA DB DC DD
permutations()
from itertools as permutation as pm
permutations('ABCD', 2)
#result: AB AC AD BA BC BD CA CB CD DA DB DC
combinations(): 조합
from itertools as combinations as cb
combinations('ABCD', 2)
#result: AB AC AD BC BD CD