python7

# # 1.可变不可变
# name = "alex"
# # name = "sb"#9764064
# v = id(name)#15989984
# print(v)
# #字符串是不可变类型
# hobby = ['coding','play']
# # print(id(hobby))#53298640
# hobby[0] = 'sb'
# print(id(hobby))#13452752
# 所以列表可变
# 数字也是不可变得
# 元祖（不可变）
# 字典，可变
# 2.访问顺序
# 1.顺序访问：字符串，列表，元祖
# 2.映射访问 字典
# 3.直接访问：数字
# #字典查询速度快，但是比较占内存
# 存放元素个数：
# 容器里类型：列表、元祖、字典
# 原子（只能存放一个值）：数字，字符串
# 3.集合
# 1.不同元素组成
# 2.无序
# 3.只能存放不可变的数据类型：数字，字符串，元组
# 4.
#####s = {1,2,6,3,5,8,}#集合
# s = {1,2,2,2,3,3,33,1}
# print(s)#{1, 2, 3, 33}
# s = set("hello")
# print(s)#{'e', 'o', 'l', 'h'}
# s = set(['alex','alex','sb'])
# print(s)#{'sb', 'alex'}
# 5.添加
# s = {1,2,3,4,5,9}
# s.add('s')
# print(s)#{1, 2, 3, 4, 5, 9, 's'}
# 6.clear
# 7.copy
# s1 = s.copy()
# print(s1)#{1, 2, 3, 4, 5, 9}
# 8.删除
# s = {1,2,3,4,5,9}
# s.pop()
#随机删除 无序
# 9.remove
# s = {1, 2, 3, 4, 5,'s',9}
# s.remove('s')
# print(s)#{1, 2, 3, 4, 5, 9}
# 10.求交集
# python_1 = ['lcg','szw','zjw']
# linux_1 = ['lcg','szw']
# p_s = set(python_1)
# l_s = set(linux_1)
# print(p_s,l_s)
# print(p_s.intersection(l_s))#{'lcg', 'szw'}
# 11.#求并集
# python_1 = ['lcg','szw','zjw']
# linux_1 = ['lcg','szw','sb']
# p_s = set(python_1)
# l_s = set(linux_1)
# print(p_s.intersection(l_s))
# print(p_s.union(l_s))#{'lcg', 'szw', 'zjw', 'sb'}
# 13.求差集
# print("差集",p_s-l_s)#存在于左边，不存在与右边
# print('差集'l_s-p_s)#存在于右边不存在于左边
# 14.交叉补集
# 合到一块，扣掉共有的部分
# print(p_s.symmetric_difference(l_s))
# print^
# 15.#取完差集之后再赋值
# python_1 = ['lcg','szw','zjw']
# linux_1 = ['lcg','szw','sb']
# p_s = set(python_1)
# l_s = set(python_1)
# p_s = p_s -l_s
# p_s.difference_update(l_s)
# print(p_s)
# 16.判断两个集合是否有交集,如果没有交集则返回True
# s1 = {1,2}
# s2 = {3,5}
# print(s1.isdisjoint(s2))
# 17.#子集
# s1= {1,2}
# s2= {1,2,3}
# print(s1.issubset(s2))#True
# print(s2.issubset(s1))#False
# 18.#fu父集
# issuperset
# 19.更新
# s1= {1,2}
# s2= {1,2,3}
# s1.update(s2)
# print(s1#{1, 2, 3}
# 20.集合的定义（不可变集合）
# s=frozenset('hello')
# print(s)#frozenset({'o', 'h', 'l', 'e'})
# 21.简单去重
# names=['alex','alex','wupeik']
# names = list(set(names))
# print(names)#['wupeik', 'alex']
# 22.字符串拼接
# msg='i am %s my hobby is alex' %'ddg'
# print(msg#i am ddg my hobby is alex
# 多个拼接
# msg='i am %s my hobby is alex %s' % ('lhf','alex')
# print(msg)#i am lhf my hobby is alex alex
# %s可以接受列表，和字符串，数字，也可以接受变量
# %d只能接受数字
# name = 'lhf'
# msg = 'i am %s my hobby is %s' % (name,19)
# print(msg)#i am lhf my hobby is 19
# 23.浮点数 保留两位
# tpl = "percent%.2f" % 99.97623444444
# print(tpl)#percent99.98
# 24.
# 以字典的形式传入字符串
# tpl = 'i am %(name)s age %(age)d' % {"name":"alex","age":18}
# print(tpl)#i am alex age 18
# 25.中间加： sep
# print('root','x','0','0',sep=':')#root:x:0:0
################################format###格式化
# 26.format()
# tpl = "i am {},age {}, {}".format("seven",18,'alex')
# print(tpl)#i am seven,age 18, alex
# tpl = "i am {2},age {1}, {0}".format("seven",18,'alex')
# print(tpl)#i am alex,age 18, seven
# 27.函数
# python中函数定义方法
# def test(x):
# "The function definitions"
# x += 1
# return x
# def:定义函数关键字
# test:函数名
# （）：内可定义参数
# "":文档描述
# x += 1:泛指代码块或程序处理逻辑
# return:定义返回值
# def test(x):
# y = 2*x + 1
# return(y)
# y = test(3)
# print(y)#7 #有参数的情况
# def test():
# x = 3
# y = 2*x + 1
# print(y)
# return(y)
# a = test()
# print(a)#7 #没有参数的情况
# 28.python按照顺序执行
# 后面的会覆盖前面的
# 29.函数的优点
# 代码重用
# 保持一致性，易维护
# 可扩展性
# 30.过程
# 过程就是没有返回值的函数
# 31.
# def test01():
# msg = 'a1'
# print(msg)

# def test02():
# msg = 'a2'
# print(msg)
# return msg
# def test03():
# msg = 'a3'
# print(msg)
# return 1,2,3,5,4,['alex'],{"gds":"12000"}
# t1 = test01()#a1
# t2 = test02()#a2
# t3 = test03()#a3
# print(t1)#Noue
# print(t2)#a2
# print(t3)#(1, 2, 3, 5, 4, ['alex'], {'gds': '12000'})
# 总结：
# 返回值个数=0：返回None
# 返回值个数=1：返回object
# 返回值个数>1:返回tuple
# 32.形参和实参
# 形参变量只有在被调用时才分配内存单元，在调用结束时，即可释放所分配的内存单元。
# 实参可以是常量、变量、表达式、函数等
# def calc(x,y):#这里的x.y是形参
# res = x**y
# return x#只要一个return运行整个函数结束
# res = calc(2,3)#这里的2、3是实参
# print(res)
# def test(x,y,z):#位置参数
# print(x)
# print(y)
# print(z)
# test(1,2,3)
# def test(x,y,z):#关键字参数
# print(x)
# print(y)
# print(z)
# test(y=1,x=2,z=3)
# 33.默认参数
# def handle(x,type="mysql"):#type = 'mysql'#默认参数
# print(x)
# print(type)
# handle("hello",type='sqlite')#
#hello
#sqlite
# 34.#参数组，*只能传位置参数，不能够传递关键字参数,以元组形式输出
# def test(x,*args):#*arge代表列表组,非固定长度参数，为后期留下扩展性
# print(x)
# print(args)
# print(args[0])
# test(1,2,3,4)
# # 1
# # (2, 3, 4)
# # 2
# 35.# 传递关键字参数 =
# def test(x,**kwargs):
# print(x)
# print(kwargs)
# test(1,y=2,z=3)
# 1
# {'y': 2, 'z': 3}
# def test(x,**kwargs):
# print(x)
# print(kwargs)
# test(1,y=2,z=3,y=3)#一个参数不能传两遍值
# 36.
# def test(x,*args,**kwargs):
# print(x)
# print(args)
# print(kwargs)
# #test(1,5,8,9,7,45,y=2,z=3)
# # 1
# # (5, 8, 9, 7, 45)
# # {'y': 2, 'z': 3}
# test(1,*[1,5,78,5,7,9],**{'y':1})
# # 1
# # (1, 5, 78, 5, 7, 9)
# # {'y': 1}