itertoolsモジュールではpermutations,combinations,productの使用

from itertools import permutations,combinations,product

#       ,    ,       ,      ,     
strs = 'abc'
#  1
def zuHe(strs):
    n = len(strs)
    if not n:
        return strs
    lts = []
    for i in range(1,n+1):
        for j in permutations(strs,i):
            flage = True #      
            for k in permutations(j):  #          ,       lts ,       
            # for k in permutations(j,i):  #permutations,    i,       
                k_strs = ''.join(k)
                if k_strs in lts:
                    flage = False
                    break
            if flage:
                j_strs = ''.join(j)
                lts.append(j_strs)
    return lts


#  2
def zuHe2(strs):
    n = len(strs)
    if not n:
        return strs
    lts = []
    for i in range(1,n+1):
        for j in combinations(strs,i):
            flage = True #      
            #           ,       lts ,           combinations      i
            for k in combinations(j,i):
                k_strs = ''.join(k)
                if k_strs in lts:
                    flage = False
                    break
            if flage:
                j_strs = ''.join(j)
                lts.append(j_strs)
    return lts

#   ,         
for m in product([1,2],repeat=3):
    print(m)
    
'''
(1, 1, 1)
(1, 1, 2)
(1, 2, 1)
(1, 2, 2)
(2, 1, 1)
(2, 1, 2)
(2, 2, 1)
(2, 2, 2)
'''
if __name__ == '__main__':
    print(zuHe(strs))  #['a', 'b', 'c', 'ab', 'ac', 'bc', 'abc']
    print(zuHe2(strs))  #['a', 'b', 'c', 'ab', 'ac', 'bc', 'abc']