python基础五

dic = {‘k1‘:"v1",
       ‘k2‘:"v2",
        "k3":[11,22,33]}
# 1)循环输出所有的key
# for i in dic.keys():
#     print(i)
# 2)循环输出所有的value
# for i in dic.values():
#     print(i)
# 3)循环所有的key与value
# for k,v in dic.items():
#     print(k,v)
# 4)在字典中添加一个键值对，‘k4’:‘v4‘
# dic[‘k4‘]=‘v4‘
# dic.setdefault(‘k4‘,‘v4‘)
# 5)请在修改字典中‘k1’对应的值为‘alex’
# 1.dic[‘k1‘]=‘alex‘
# 2.dic1 = {‘k1‘:‘alex‘}
#   dic.update(dic1)
# 6)在k3对应的值中追加一个元素44
# dic[‘k3‘].append(44)
# 7)在k3对应的值的第一个位置插入一个元素18
#dic[‘k3‘].insert(0,‘18‘)

# li=[11,22,33,44,55,66,77,88,99,90]
# dic = {‘key1‘:[],‘key2‘:[]}
# for i in li :
#     if i >= 66:
#         dic[‘key1‘].append(i)
#     else:
#         dic[‘key2‘].append(i)
# print(dic)

li = ["手机","电脑","鼠标垫","游艇"]
msg = ‘‘‘
    1:页面显示
    2：查询商品信息
    Q：退出系统
‘‘‘
while 1:
    operate = input("请输入您需要的操作"+msg)
    if operate == ‘1‘:
        for i in li :
            print(li.index(i)+1,i)
    elif operate == ‘2‘:
        order = int(input("请输入商品序号"))-1
        if order > 3 or order<1:
            print("序号有误")
            break
        else :
            print(order+1,li[order])
    elif operate.lower() ==‘q‘:
        break
    else:
        operate = input("输入有误,重新输入")