学习python，每日练习20200819

笛卡尔积、排列、组合

#网址：https://blog.youkuaiyun.com/huangzhiyuan111/article/details/52586316
import itertools
#新知识点
#笛卡尔积
list = [2,3,1,6]
for i in itertools.product(list,repeat=2):
    #返回的类型为“tuple”
    print(i,end = '')
#结果：(2, 2)(2, 3)(2, 1)(2, 6)(3, 2)(3, 3)(3, 1)(3, 6)(1, 2)(1, 3)(1, 1)(1, 6)(6, 2)(6, 3)(6, 1)(6, 6)
print()
print("***********************************************")
#permutations 排列
for i in itertools.permutations(list,2):
    # 返回的类型为“tuple”
    print(i,end = '')
#结果：(2, 3)(2, 1)(2, 6)(3, 2)(3, 1)(3, 6)(1, 2)(1, 3)(1, 6)(6, 2)(6, 3)(6, 1)
print()
print("***********************************************")
#combinations 组合,没有重复
for i in itertools.combinations(list,2):
    # 返回的类型为“tuple”
    print(i,end = '')
#结果：(2, 3)(2, 1)(2, 6)(3, 1)(3, 6)(1, 6)
print()
print("***********************************************")
#combinations_with_replacement 组合,有重复
for i in itertools.combinations_with_replacement(list,2):
    # 返回的类型为“tuple”
    print(i,end = '')

#结果：(2, 2)(2, 3)(2, 1)(2, 6)(3, 3)(3, 1)(3, 6)(1, 1)(1, 6)(6, 6)

'''
(2, 2)(2, 3)(2, 1)(2, 6)(3, 2)(3, 3)(3, 1)(3, 6)(1, 2)(1, 3)(1, 1)(1, 6)(6, 2)(6, 3)(6, 1)(6, 6)
***********************************************
(2, 3)(2, 1)(2, 6)(3, 2)(3, 1)(3, 6)(1, 2)(1, 3)(1, 6)(6, 2)(6, 3)(6, 1)
***********************************************
(2, 3)(2, 1)(2, 6)(3, 1)(3, 6)(1, 6)
***********************************************
(2, 2)(2, 3)(2, 1)(2, 6)(3, 3)(3, 1)(3, 6)(1, 1)(1, 6)(6, 6)
'''