集合

!/usr/bin/env python
-*- coding:utf-8 -*-
Author:Alex Li
1、set，无序，不重复序列
li = [11,222]
print(li)
a. 创建
li = []
list((11,22,33,4))
list __init__,内部执行for循环(11,22,33,4) [11,22,33,4]
原理，list
dic = {"k1":123}
se = {"123", "456"}
s = set() # 创建空集合
li = [11,22,11,22]
s1 = set(li)
print(s1)
##可以创建空集合，集合是无序的，也可以通过sed的方法将列表转换成集合。
b. 功能
set()\

创建集合
s1 = {11,22}
s2 = set()
s3 = set([11,22,33,4])
##总结起来2种方式创建集合，直接创建，通过set的方法转换

# 操作集合
s = set()
print(s)
s.add(123)
s.add(123)
s.add(123)
print(s)
s.clear()
print(s)
##往集合添加元素，

s1 = {11,22,33}
s2 = {22,33,44}
s3 = s1.difference(s2)
A中存在，B中不存在
s3 = s2.difference(s1)
s3 = s1.symmetric_difference(s2)
print(s1)
print(s2)
print(s3)
s1.difference_update(s2)
##自己试验下就知道用途了，取各自不在的组成一起
s1.symmetric_difference_update(s2)
print(s1)

s1 = {11,22,33}
s1.discard(1111)
s1.remove(11111)
ret = s1.pop()
print(s1)
print(ret)
##集合的删除，discare是remove的友好版本

s1 = {11,22,33}
s2 = {22,33,44}
s3 = s1.union(s2)
print(s3)
##取集合并集
s3 = s1.intersection(s2)
s1.intersection_update(s2)
##直接修改s1,不创建新变量
print(s3)
"""
s1 = {11,22,33}
s1.add(11)
s1.add(12)
s1.add(13)
li = [11,22,3,11,2]
li = (11,22,3,11,2)
li = "alexalex"
s1.update(li)
print(s1)
"""

li = [11,22,33] # list __init__
li() # list __call__
li[0] # list __getitem__
li[0] = 123 # list __setitem__
def li[1] # list __delitem__
old_dict = {
"#1": 8,
"#2": 4,
"#4": 2,
}

new_dict = {
"#1": 4,
"#2": 4,
"#3": 2,
}
old_kyes = old_dict.keys()
old_set = set(old_kyes)
new_set = set(new_dict.keys())
old_set = set(old_dict.keys())

remove_set = old_set.difference(new_set)
add_set = new_set.difference(old_set)
update_set = old_set.intersection(new_set)

import re
re.match()