python之字典

基本操作：

# Author:yebo

info = {
    'stu01':"yebo",
    'stu02':"shuz",
    'stu03':"yomi"
}


#改
info['stu01'] = "松江小旋风"

#增
info['stu04'] = "7zai"
print(info)

#删
info.pop('stu02')
print(info)

#查
print(info.get('stu01'))
print('stu01' in info)   #判断有无此key值

#循环打印
for i in info:
    print(i,info[i])   #法一,更好

for k,v in info.items():
    print(k,v)   #法二

三级菜单：

# Author:yebo

data = {
    'shanghai' : {
        'songjiang' :{
            "sues" : ["ysh","zcx"]   #最后用[]或者{}都可以
        },
        'xuhui' :{
            "jiaoda" : {"jb"}
        }
    },
    'changsha' : {
        'yuelu' :{
            "huzhongda" :{"shuzhui","yomi"},
            "hunanshida" : {"yt"},
            "zhongnan" : {"shuzhe"}
        },
        'kaifu' :{
            "changli" : {"kzr"}
        }
    }
}

exit_flag = False

while not exit_flag:   #重点!!!!!!
    for i in data:
        print(i)   #打印一级菜单
    choice = input("选择进入1>>>:")   #进入第一级菜单
    if choice in data:
        while not exit_flag:
            for i2 in data[choice]:
                print("\t",i2)   #打印二级菜单
            choice2 = input("选择进入2>>>:")   #进入第二级菜单
            if choice2 in data[choice]:
                while not exit_flag:
                    for i3 in data[choice][choice2]:
                        print("\t\t", i3)   #打印三级菜单
                    choice3 = input("选择进入3>>>:")   #进入第三级菜单
                    if choice3 in data[choice][choice2]:
                        for i4 in data[choice][choice2][choice3]:
                            print("\t\t\t", i4)   #打印三级菜单中内容
                        choice4 = input("最后一层，按b返回>>>:")
                        if choice4 == 'b':
                            pass
                        elif choice4 == 'q':
                            exit_flag = True
                    if choice3 == 'b':
                        break
                    elif choice3 == 'q':
                        exit_flag = True
            if choice2 == 'b':
                break
            elif choice2 == 'q':
                exit_flag = True
    elif choice == 'q':
        exit_flag = True

购物车：

自己的垃圾版本：（缺少许多的用户输入验证if判断）

# Author:yebo


items = [
    [1,"iphone",5800],
    [2,"mac pro",12000],
    [3,"latte",31],
    [4,"python start",81],
    [5,"bike",800]
]
shopping_list = []   #提前准备一个空集

my_salary = int(input("my salary:"))

while True:
    print(items)
    items_number = int(input("which one do you want to buy?"))
    items_index = items_number - 1   #实际列表排序从0开始

    if items[items_index][2] > my_salary:
        print("you do not have enough money")
    else:
        my_salary = my_salary - items[items_index][2]
        print("you have bought %s,which is %d, my salary remain:%d"
              %(items[items_index][1],items[items_index][2],my_salary))
        shopping_list.append(items[items_index][1])

    continue_confirm = input("if you want to quit, please press 'q'; if not, please press any key.")
    if continue_confirm == "q":
        break

print("***----list----***")
print("you have bought:")
for i in shopping_list:
    print(i)
print("***------------***")

老男孩ALex老师版本：

__author__ = "Alex Li"


product_list = [
    ('Iphone',5800),
    ('Mac Pro',12000),
    ('Bike',800),
    ('Watch',30000),
    ('Coffee',30),
    ('Alex Python',120),
]
shopping_list = []
salary = input("Input your salary:")
if salary.isdigit():   #判断输入是否是数字
    salary = int(salary)
    while True:
        for index,item in enumerate(product_list):   #方法一：enumerate在同时需要index和value的时候使用
            #print(product_list.index(item),item)  #方法二：用.index增加了商品编号
            print(index,item)
        user_choice = input("选择要买嘛？>>>:")
        if user_choice.isdigit():   #判断输入是否是数字
            user_choice = int(user_choice)
            if 0 <= user_choice < len(product_list):   #len（）直接得到列表长度
                p_item = product_list[user_choice]   #取出购买的商品
                if p_item[1] <= salary:  #买的起
                    shopping_list.append(p_item)   #增加到购物车
                    salary -= p_item[1]
                    print("Added %s into shopping cart,your current balance is \033[31;1m%s\033[0m" %(p_item,salary) )
                else:
                    print("\033[41;1m你的余额只剩[%s]啦，还买个毛线\033[0m" % salary)   #增加字体颜色
            else:
                print("product code [%s] is not exist!"% user_choice)
        elif user_choice == 'q':
            print("--------shopping list------")
            for p in shopping_list:
                print(p)
            print("Your current balance:",salary)
            exit()
        else:
            print("invalid option")