集合的相关操作

集合元素的判断操作：

in 或者 not in 

a={1,2,3,4,5,"我","python","你好"}

print(1 in a)                       True

print(1 not in a)                 False

print("我" in a )                 True

print("我们" not in a )      True

增删改查

discard( )  （抛弃，丢弃） 一次删除一个指定元素

a={1,2,3,4,5,"我","python","你好"}

a.discard(1)

print(a)

{2,3,4,5,"我","python","你好"}

remove( ) （去除，去掉）  一次删除一个指定元素

a={1,2,3,4,5,"我","python","你好"}

a.remove(5)

print(a)

{1,2,3,4,"我","python","你好"}

pop（ ） 后面不能放参数，放参数就会报错，一次只删除一个任意元素，删除元素是随机的

a={1,2,3,4,5,"我","python","你好"}

a.pop( )

print(a)

{1,2,3,4,"我","python","你好"} 也有可能   a={1,2,3,4,5,"我","python"}  随机删除一个元素

add( ) 添加  一次添加一个元素 ，添加成功后的元素位置是随机的

a={1,2,3,4,5,"我","python","你好"}

a.add("我们")

print(a)

{1,2,3,4,5,"我","我们","python","你好"}

update( )     更新   至少添加一个元素

注意：a.update( {“字符串”} ) 将字符串添加到集合中，有重复的会忽略。

            a.update( “字符串” ) 将字符串拆分单个字符后，然后再一个个添加到集合中，有重复的会忽略。

a={1,2,3,4,5,"我","python","你好",6,7,8,9}

a.update([10,11,"我们"])

print(a)

{1,2,3,4,5,"我","python","你好",6,7,8,9,10,11,"我们"}

a={1,2,3,4,5,"我","python","你好",6,7,8,9}

a.update(["我们"])

print(a)

{1,2,3,4,5,"我","python","你好",6,7,8,9，"我","们"}

clear( )  清空集合

a={1,2,3,4,5,"我","python","你好",6,7,8,9}

a.clear( )

print(a)

set( )

71.集合的相关操作_哔哩哔哩_bilibili    9.23