1.统计下面字符串中每个单词出现的次数,并生成一个字典,字典作为key,次数作为value
实现思路:1.使用空格作为分隔符将字符串进行分割,得到list
2.遍历上一步中得到的list
3.将单词提取出来,生成一个字典
4.如果单词不存在,就以该值作为key,1作为value存储到字典中
5.如果单词存在,该单词对应的value递增1【修改键值对】#法一: str1 = "tomorrow is a good day tomorrow is a bad day tomorrow is a sunny day" list1 = str1.split(" ") dict1 ={} for element in list1: if element not in dict1: dict1[element] = 1 else: dict1[element] += 1 print(dict1) #法二: str1 = "tomorrow is a good day tomorrow is a bad day tomorrow is a sunny day" list1 = str1.split(" ") dict1 ={} for element in list1: value = dict1.get(element) #如果不存在则返回None if value == None: dict1[element] = 1 else: dict1[element] += 1 print(dict1)
2.给定对应的时间【时分秒】,打印出该时间的下一秒
timeStr = input("请输入正确格式的时间:") timeList = timeStr.split(":") h = int(timeList[0]) m = int(timeList[1]) s = int(timeList[2]) s += 1 if s == 60: m += 1 s = 0 if m == 60: h += 1 m = 0 if h == 24: h = 0 print("%.2d:%.2d:%.2d"%(h,m,s))
3.实现一个简单的购物车功能
引导用户选择商品;引导用户输入金额;加入购物车;查看购物车,计算余额productList = [("book",50),("kindle",500),("iphone x",8000),("food",100)] #商品列表 shoppingCar = [] #购物车 saving = input("请输入金额:") #判断金额是否是纯数字 if saving.isdigit(): saving = int(saving) #将对应的saving转化为数字类型 #添加商品: while True: for i,p in enumerate(productList): print(i,":",p) #引导用户选择商品 choice = input("请输入商品编号[输入q退出]:") if choice.isdigit(): choice = int(choice) if choice >= 0 and choice <= len(productList): #将用户选择的商品从productList中取出来 item = productList[choice] #元组item[0]:商品名称,item[1]:商品价格 if saving >= item[1]: #减少saving saving -= item[1] #将商品添加到购物车中 shoppingCar.append(item) else: print("编号不存在") elif choice == "q": print("------购物车中有如下商品--------") for i in shoppingCar: print(i) print("还剩余%d钱"%saving) break else: print("无效输入") else: print("无效输入")