# 今日作业： # 1.简述 # 什么是迭代器 # 1、   迭代是一个重复的过程，并且每次重复都是基于上一次的结果而来 仅仅循环，不是迭代 # 什么是可迭代对象 # 在python中，但凡内置有__iter__方法的对象，都是可迭代的对象 # 什么是面向过程编程 #   核心是'过程'二字，过程即解决问题的步骤，即先干什么，再干什么。。。。 #   基于面向过程编写程序就好比在设计一条流水线，是一种机械式的思维方式。 # 2.自定义生成器 实现 range功能 # def my_range(start,stop,step=1): #     while start < stop: #         yield start#yield 4 #         start+=step # # abc=my_range(1,5,1) # print(next(abc)) # print(next(abc)) # print(next(abc)) # 3、文件shopping.txt内容如下 # mac,2000,3 # lenovo,3000,10 # tesla,1000000,10 # chicken,200,1 # # with open(r'shopping.txt','w',encoding='utf-8') as f: #     f.writelines(['mac,2000,3\n', #             'lenovo,3000,10\n', #             'tesla,1000000,10\n', #             'chicken,200,1\n']) # # 求总共花了多少钱？ # with open(r'shopping.txt','r',encoding='utf-8') as f: #     info=[line.strip('\n').split(',') for line in f] #     res=sum(int(i[1])*int(i[2]) for i in info) #     print(res) # 打印出所有的商品信息，格式为 # [{'name':'xxx','price':'3333','count':3},....] # l=[] # with open(r'shopping.txt','r',encoding='utf-8') as f: #     for line in f: #         dic={} #         info=line.strip('\n').split(',') #         dic['name'] = info[0] #         dic['price'] = info[1] #         dic['count'] = info[2] #         l.append(dic) # print(l) # 求单价大于10000的商品信息，格式同上 # with open(r'shopping.txt',encoding='utf-8') as f: #     info=[{
  #         'name': line.strip('\n').split(',')[0], #         'price': float(line.strip('\n').split(',')[1]), #         'count': int(line.strip('\n').split(',')[2]) } #         for line in f if float(line.strip('\n').split(',')[1] )> 10000] #     print(info) # 4、文件内容如下,标题为:姓名,性别,年纪,薪资 # egon male 18 3000 # alex male 38 30000 # wupeiqi female 28 20000 # yuanhao female 28 10000 # # with open(r'salary.txt','w',encoding='utf-8') as f: #     f.writelines(['egon male 18 3000\n', #             'alex male 38 30000\n', #             'wupeiqi female 28 20000\n', #             'yuanhao female 28 10000\n']) # # 要求: # # 从文件中取出每一条记录放入列表中,列表的每个元素都是{'name':'egon','sex':'male','age':18,'salary':3000}的形式 l=[] with open(r'salary.txt','r',encoding='utf-8') as f:     for line in f:         dic={}         info=line.split()         dic['name'] = info[0]         dic['sex'] = info[1]         dic['age'] = info[2]         dic['salary'] = info[3]         l.append(dic) print(l) # # 5 根据1得到的列表,取出薪资最高的人的信息 # print(max(l,key=lambda dic:dic['salary'])) # # 6 根据1得到的列表,取出最年轻的人的信息 # print(min(l,key=lambda dic:dic['age'])) # # 7 根据1得到的列表,将每个人的信息中的名字映射成首字母大写的形式 # l1=[] # with open(r'salary.txt','r',encoding='utf-8') as f: #     for line in f: #         dic1={} #         info=line.strip('\n').split(' ') #         dic1['name'] = info[0].capitalize() #         dic1['sex'] = info[1] #         dic1['age'] = info[2] #         dic1['salary'] = info[3] #         l1.append(dic1) # print(list(l1)) # 8 根据1得到的列表,过滤掉名字以a开头的人的信息 g=filter(lambda item:item['name'].startswith('a'),l) print(list(g)) l.remove({'name': 'alex', 'sex': 'male', 'age': '38', 'salary': '30000'}) # l.pop(1) print(l)