列表——元组——字典——集合:
列表:
# 一:基本使用
# 1、用途:存放多个值
# 定义方式:[]内以逗号为分隔多个元素,列表内元素无类型限制
# l=['a','b','c'] #l=list(['a','b','c'])
# l1=list('hello')
# print(l1)
# 常用操作+内置的方法
# 按索引存取值(正向存取+反向存取):即可改也可以取
l = ['a', 'b', 'c']
print(id(l))
print(l[-1])
l[0] = 'A'
print(id(l))
print(l)
l[3] = 'd' # 报错
# 2、切片(顾头不顾尾,步长)
stus = [1,2,3,'a','b','c']
print(stus[1:3])
# 3、长度
# stus = [1,2,3,'a','b','c']
# print(len(stus))
# 4、成员运算in和not in
# stus = [1,2,3,'a','b','c']
# print('a' in stus)
# 5、追加
# stus = [1,2,3,'a','b','c']
# stus.append('d')
# stus.append('c')
# print(stus)
# 插入
# stus = [1,2,3,'a','b','c']
# stus.insert(1,'x')
# print(stus)
# 6、删除
# stus = [1,2,3,'a','b','c']
# del stus[1]
# print(stus)
# stus.remove('a')
# print(stus)
# stus.pop(1)
# stus.pop() # 默认删除末尾
# print(stus)
# res1=stus.remove('c') # 单纯的删除
# print(res1)
# res2=stus.pop(0) # 取走一个值
# print(res2)
# 7、循环
# stus = [1,2,3,'a','b','c']
# 依赖索引
# i=0
# while i < len(stus):
# print(stus[i])
# i+=1
# for i in range(len(stus)):
# print(i,stus[i])
# 不依赖索引
# for item in stus:
# print(item)
# 补充for循环
# for i in range(0,5,2): #0 2 4
# print(i)
# for i in range(10):#默认从零起始
# print(i)
# for i in range(10,-2,-1):
# print(i)
元组:
# 元组:相当于不可变的列表
# t = (1, 2, 3, 'a', 'b', 'c')
# print(id(t[2]))
# 用途:当存放的多个值,只有读的需求,没有改的需求时,可以用元组
# 常用操作:
# 依赖索引
# t = (1, 2, 3, 'a', 'b', 'c')
#
# i = 0
# while i < len(t):
# print(t[i])
# i += 1
#
# for i in range(len(t)):
# print(t[i])
#
#
# # 不依赖索引
# for item in t:
# print(item)
#
# list('hello')
# v = list(t)
# v = set(t)
# v = tuple(t)
字典:
# 根据数列,创建字典,并制定统一的值:
dic = {
'asd': '123',
'qx': 'cac'
}
# v = dict.fromkeys(['asd', 113, 'gsd'],123)
# v = dic['qx']
# v = dic.get('aad',12321)
# v = dic.pop('aasd', 121)
# v = dic.popitem()
# v = dic.setdefault('qx', '12e')
# v = dic.update({'qwd':'1321','fas':1231})
# print(dic)
# print(v)
# dic.keys() .values() .items() .get() .update()
集合:
# 定义:
# s1={1,2,3, 'a', 'b', 'c'}
# s2={4,5,6, 'a', 'b'}
# 注意:
# 集合无序
# 集合内元素不能重复
# 集合内的元素必须为不可变类型,但set集合是可变
# 用途:
# 集合使用来进行关系元素,单独取集合的某一个元素是没有意义,也没有相应的方法
#
# 交集:s1 & s2取两个集合的共同部分
# 差集:s1-s2,结果存于s1而不存于s2的元素集合
# 补集:s1 ^ s2,扣掉s1与s2共同部分,剩下的部分合到一起
# 并集:s1 | s2把两个合到一起,去掉重复
购物程序:
product_list=[
('Mac Book',9000),
('Mate Book',8000),
('Magic Book',5000),
('Think Pad',4000),
('Lenovo',5000),
('SAMSUNG',7000),
('OPPO',3000),
('MI',2500),
('HUAWEI',4500),
]
saving=input('请输入你的钱:')
shopping_car=[]
if saving.isdigit():
saving=int(saving)
while True:
for i,v in enumerate(product_list,1):
print(i,'>>>>',v)
choice=input('请选择购买的商品号:[结束购买请输入:W]: ')
if choice.isdigit():
choice=int(choice)
if choice>0 and choice<=len(product_list):
p_item=product_list[choice-1]
if p_item[1]<saving:
saving-=p_item[1]
shopping_car.append(p_item)
else:
print('余额不足,还剩%s'%saving)
print(p_item)
else:
print('您输入的号码不正确,请重新输入')
elif choice=='W':
print(
'------------您已经购买如下商品--------------'
)
for i in shopping_car:
print(i)
print('您还剩%s元钱'%saving)
break
else:
print('invalid input')