.pop ----remove 删除

s = {1,2,3,4,5,6,'sn','7'}
s.pop()#删除随机值
print(s)#{2, 3, 4, 5, 6, '7', 'sn'}
s.remove('sn')#删除值
print(s)#{1, 2, 3, 4, 5, 6, '7'}