python中集合知识介绍

#集合 不容许有重复元素 可以进行交集，并集，差集
# 创建集合的字面量语法
set1 = {1, 2, 3, 3, 3, 2}
print(set1) #{1, 2, 3}
print('Length =', len(set1)) # Length = 3
# 创建集合的构造器语法(面向对象部分会进行详细讲解)
set2 = set(range(1, 10))
set3 = set((1, 2, 3, 3, 2, 1))
print(set2, set3) #{1, 2, 3, 4, 5, 6, 7, 8, 9} {1, 2, 3}
# 创建集合的推导式语法(推导式也可以用于推导集合)
set4 = {num for num in range(1, 100) if num % 3 == 0 or num % 5 == 0}
print(set4) #{3, 5, 6, 9, 10, 12, 15, 18, 20, 21, 24, 25, 27, 30, 33, 35, 36, 39, 40, 42, 45, 48, 50, 51, 54, 55, 57, 60, 63, 65, 66, 69, 70, 72, 75, 78, 80, 81, 84, 85, 87, 90, 93, 95, 96, 99}

set1.add(4)
set1.add(5)
set2.update([11, 12])
set2.discard(5)
if 4 in set2:
    set2.remove(4)
print(set1, set2) #{1, 2, 3, 4, 5} {1, 2, 3, 6, 7, 8, 9, 11, 12}
print(set3.pop()) # 1
print(set3)       # {2, 3}

 

# 集合的交集、并集、差集、对称差运算
print(set1 & set2) #{1, 2, 3}
# print(set1.intersection(set2))
print(set1 | set2) #{1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12}
# print(set1.union(set2))
print(set1 - set2) #{4, 5}
# print(set1.difference(set2))
print(set1 ^ set2) #{4, 5, 6, 7, 8, 9, 11, 12}
# print(set1.symmetric_difference(set2))
# 判断子集和超集
print(set2 <= set1)  #False
# print(set2.issubset(set1))
print(set3 <= set1)  #True
# print(set3.issubset(set1))
print(set1 >= set2)  #False
# print(set1.issuperset(set2))
print(set1 >= set3)  #True
# print(set1.issuperset(set3))