一、元素分类
有如下值集合[11,22,33,44,55,66,77,88,99]，将所有大于66 的值保存在字典的第一个key中，将小于66的值放在另一个key中，即：{‘k1’:大于66的所有值，‘k2’:小于66的所有值}
li = [11,22,33,44,55,66,77,88,99] dic={ "k1":[], "k2":[] } for i in li: if i<=66: dic['k1'].append(i) else: dic['k2'].append(i) print(dic) #输出结果 {'k2': [77, 88, 99], 'k1': [11, 22, 33, 44, 55, 66]}
二、查找
查找列表中元素，移动空格，并查找以a或者A开头并且以c结尾的所有元素
li=["alec", "aric", "Alex", "Tony", "rain"]
tu=("alec", "aric", "Alex", "Tony", "rain")
dic={'k1': "alex", 'k2': 'aric', 'k3': "Alex", "k4": "Tony"}
li=["aleb","alec", "aric", "Alex", "Tony", "rain"] for i in li: #print(i) #i表示每一个元素 new_i = i.strip() #if判断的顺序，从前到后，OR，自己成功就行，AND if (new_i.startswith('a') or new_i.startswith('A')) and new_i.endswith('c'): print(i) #输出结果 alec aric
tu=("alec", "aric", "Alex", "Tony", "rain") for i in tu: #print(i) #i表示每一个元素 new_i = i.strip() #if判断的顺序，从前到后，OR，自己成功就行，AND if (new_i.startswith('a') or new_i.startswith('A')) and new_i.endswith('c'): print(i) #输出 alec aric
dic={'k1': "alex", 'k2': 'aric', 'k3': "Alex", "k4": "Tony"}
for i in dic.values():
#print(i) #i表示每一个元素
new_i = i.strip()
#if判断的顺序，从前到后，OR，自己成功就行，AND
if (new_i.startswith('a') or new_i.startswith('A')) and new_i.endswith('c'):
print(i)
#输出
aric
三、输出商品列表，用户输入序号，显示用户选中的商品
商品li=["手机","电脑","鼠标垫", "游艇"]
li = ["手机","电脑","鼠标垫","游艇"] for i,j in enumerate(li): print(i+1,j) num = input('num: ') num = int(num) len_li=len(li) if num>0 and num<=len_li: #索引 good = li[num-1] print(good) else: print("商品不存在！")
四、购物车
功能要求：
要求用户输入总资产，例如：2000
显示商品列表，让用户根据序号选择商品，加入购物车
购买，如果商品总额大于总资产，提示账户余额不足，否则，购买成功
附加：课重置、某商品移除购物车
goods=[ {"name":"电脑","price":1999}, {"name":"鼠标","price":19}, {"name":"游艇","price":998}, {"name":"键盘","price":20} ]
解答一
asset_all = 0 i1= input("请输入总资产：") asset_all = int(i1) car_list = [] # { # "电脑":{'price': "单个商品的价格：","num":"购买多少个！"} # } goods = [ {"name": "电脑", "price": 1999}, {"name": "鼠标", "price": 19}, {"name": "游艇", "price": 998}, {"name": "键盘", "price": 20} ] for i in goods: #i,每一个列表的元素，字典 #["price": 1999,'name': "电脑'] print(i['name'],i['price']) while True: i2 = input("请选择商品（Y/y结算）:") if i2.lower() == "y": break for j in goods: if j['name'] == i2: #print(j) car_list.append(j) #print(car_dict) #总和 print(car_list) all_price=0 for item in car_list: p=item['price'] all_price += p print(asset_all,all_price) if all_price > asset_all: print("余额不足！") else: print("购买成功！") #输出结果 请输入总资产：1000 电脑 1999 鼠标 19 游艇 998 键盘 20 请选择商品（Y/y结算）:电脑 请选择商品（Y/y结算）:y [{'name': '电脑', 'price': 1999}] 1000 1999 余额不足！
解答二（用字典的方式保存商品）
#总资产 asset_all = 0 i1= input("请输入总资产：") asset_all = int(i1) goods = [ {"name": "电脑", "price": 1999}, {"name": "鼠标", "price": 19}, {"name": "游艇", "price": 998}, {"name": "键盘", "price": 20} ] for i in goods: #i,每一个列表的元素，字典 #["price": 1999,'name': "电脑'] print(i['name'],i['price']) car_dict={} # car_dict={ # "电脑":{'price':123,'num':345} # } while True: i2 = input("请选择商品(Y/y结算)：") if i2.lower() == "y": break #循环所有的商品，查找需要的商品 for item in goods: if item["name"] == i2: name = item['name'] #判断购物车是否已经有该商品，有，num+1； if name in car_dict.keys(): car_dict[name]['num'] = car_dict[name]['num'] + 1 else: car_dict[name] = {'num': 1, 'single_price': item['price']} print(car_dict) # { # '鼠标':{'single_price':10,'num':1},#1*10 # '电脑':{'single_price':1999,'num':9} # # } all_price = 0 for k,v in car_dict.items(): n = v['single_price'] m = v['num'] all_sum = m * n all_price = all_price + all_sum if all_price > asset_all: print("余额不足") else: print("购买成功") #输出结果 请输入总资产：100000 电脑 1999 鼠标 19 游艇 998 键盘 20 请选择商品(Y/y结算)：电脑 请选择商品(Y/y结算)：电脑 请选择商品(Y/y结算)：电脑 请选择商品(Y/y结算)：y {'电脑': {'num': 3, 'single_price': 1999}} 购买成功
五、用户交互，显示省市县三级联动的选择
dic = { "河北": { "石家庄": ["鹿泉","邺城" "元氏"], "邯郸": ["永年", "涉县", "磁县"] }, "湖南":{ "长沙":["岳麓","开福","芙蓉"], "株洲":["中车", "608", "331"] }, "江西":{ "南昌":["红谷滩","新建","青山湖"], "抚州":["临川","广昌","鹰潭"] }, }
#解答
dic = { "河北": { "石家庄": ["鹿泉","邺城" "元氏"], "邯郸": ["永年", "涉县", "磁县"] }, "湖南":{ "长沙":["岳麓","开福","芙蓉"], "株洲":["中车", "608", "331"] }, "江西":{ "南昌":["红谷滩","新建","青山湖"], "抚州":["临川","广昌","鹰潭"] }, } #循环输出所有的省 for x in dic: print(x) i1 = input("请输入省份：") a = dic[i1] #循环所有的市 for j in a: print(j) i2 = input("请输入市：") b=dic[i1][i2] print(b) #list __str__ for z in b: print(z)