20190129-‘abcdefgh’里

e = 'abcdefghi'

#第一个字符
    for j in e:
        #第二个字符
        for k in e:
            #第三个字符
            if i!=j and j!=k and k!=i:
                for item in result:
                    if i in item and j in item and k in item:
                        break
                else:
                    #与for item in result对应，当for主体中没有执行break语句的时候，else语句执行   
                    item= i+j+k
                    result.append(item)
                    count+=1
print("共计%s个"%count)
print('分别为:',result)

e = 'abcdefghi'
#方法2：
#三个字母同时出现的次数只能出现一次,可以考虑使用sort来实现，如sorted(item) not in list(map(lambda x:sorted(x),for x in result_two))来实现，具体写法
count_two=0
result_two=[]
for i in e:
    #第一个字符
    for j in e:
        #第二个字符
        for k in e:
            #第三个字符
            item = i+j+k
            if item.count(i)>1 or item.count(j)>1 or item.count(k)>1:
                continue
            if sorted(list(item)) not in list(map(lambda x:sorted(x),result_two)):
                result_two.append(item)
                count_two+=1
print("共计%s个"%count_two)
print('分别为:',result_two)

import itertools 
count_three= 0
result_three=[]
for i in itertools.combinations(e,3):
    count_three+=1
    result_three.append(''.join(i))
print("共计%s个"%count_three)
print('分别为:',result_three)