python学习-21 集合 2

集合的其他方法

1.交差补集

math = {'xm','xh','xg','xx'}
english ={'xm','xh','dm','john'}

print(math.symmetric_difference(english))

运行结果：

{'dm', 'john', 'xx', 'xg'}

Process finished with exit code 0

2.如果交集李没有重复的返回True

math = {'xm','xh','xg','xx'}
english ={'xd','xb','dm','john'}

print(math.isdisjoint(english))

运行结果：

True

Process finished with exit code 0

3.math 是 English的子集

math = {'xm','xh','xg','xx'}
english ={'xd','xb','dm','john'}

print(math.issubset(english))

运行结果：

False       （因为不是，所以返回false）

Process finished with exit code 0

4.更新（可以更新多个值）

math = {'xm','xh','xg','xx'}
english ={'xd','xb','dm','john'}
math.update(english)
print(math)

运算结果：

{'xm', 'xh', 'john', 'xb', 'xd', 'dm', 'xx', 'xg'}

Process finished with exit code 0

ps：不可变集合

s = frozenset('hello')
print(s)

运行结果：

frozenset({'e', 'l', 'h', 'o'})

Process finished with exit code 0