1、集合{}:可变数据类型,他里边的元素必须是不可变的,无序,不重复,
set1 = set({1,2,3})
print(set1)
# 集合的表现 '''set1 = set({1,2,3}) #set2 = {1,2,3,[2,3],{'name':'liang'}} # 报错 不可变就是可哈希的 print(set1) print(set2) ''' # 集合的增删查,不能改 # set1 = {'jinzha','muzha','nezha','xiaoliongnv'} # 增 随机增加 '''set1.add('小猪熊') print(set1) # update 加一个列表,列表中的每一个元素都在里边,随机 set1.update('abc') print(set1)''' # 删 pop 随机删除 '''set1.pop() print(set1) print(set1.pop()) # remove 按元素删 set1.remove('nezha') print(set1) # clear 清空集合 set()表示空集合 set1.clear() print(set1) # del 删除整个集合 报错 del set1 print(set1)''' # 查 用for循环去查 '''for i in set1: print(i) ''' # 交集 '''set1 = {1,2,3,4,5} set2 = {4,5,6,7,8} print(set1 & set2) # {4,5} print(set1.intersection(set2)) # {4,5}''' # 并集 '''set1 = {1,2,3,4,5} set2 = {4,5,6,7,8} print(set1 | set2) # {1,2,3,4,5,6,7,8} print(set1.union(set2)) # {1,2,3,4,5,6,7,8}''' # 差集 set1 独有的 重复的部分删去 '''set1 = {1,2,3,4,5} set2 = {4,5,6,7,8} print(set1 - set2) # {1,2,3} print(set1.difference(set2)) # {1,2,3}''' # 子集与超集 '''set1 = {1,2,3} set2 = {1,2,3,4,5,6} print(set1 < set2) # 说明set1是set2的子集 True print(set1.issubset(set2)) # True print(set2 > set1) # 说明set2是set1的超集 True print(set2.issuperset(set1)) # True''' # 面试题 列表中去除重复的,set比算法快 '''li = [1,2,33,33,2,1,4,5,6,6] set1 = set(li) print(set1) li = list(set1) print(li)''' # 可变数据类型转换为不可变数据类型 # 创建不可变集合 '''b = frozenset('runoob') print(b,type(b)) for i in b: #可查无序的 不可增删改查 print(i)''' # 生成一个新的不可变集合 ''' a = frozenset(range(10)) print(a)'''
2、基础数据类型汇总补充
str int list bool dict tupe
Ctrl点击 str 或 int 可转到使用界面,可自己了解
#循环列表和字典的时候不要删他的东西,删就会很麻烦容易报错 dic = {'k1':'v1','k2':'v2','a3':'v3'} # 1、循环字典当中你不能删除他的键 ''' dic1 = {} for i in dic: if 'k' not in i: dic1.setdefault(i,dic[i]) dic = dic1 print(dic) ''' # 2、把含有k的键放在一个列表里,循环列表删除字典所要删除的东西 '''l = [] for i in dic: if 'k' in i : l.append(i) for i in l: del dic[i] print(dic) ''' # 什么数据类型转化为bool是Forst int = 0 str = '' list = [] tup = () dict = {} set = () # 元组 # 如果元组里边只有一个元素且不加','此元素是什么类型,print结果就是什么类型 '''tup1 = (1) tup2 = (1,) tup3 = ([1]) tup4 = ([1],) print(tup1,type(tup1)) print(tup2,type(tup2)) print(tup3,type(tup3)) print(tup4,type(tup4)) '''