内置函数详细信息:https://docs.python.org/3/library/functions.html?highlight=built#ascii
1、abs():返回绝对值
2、all():Return True if bool(x) is True for any x in the iterable.If the iterable is empty, return False.
3、ascii():返回ASCII码
4、bin():返回整数的二进制
5、bool():判断一个数据结构是True还是False
6、bytes():将里面的字符串变成bytes类型
7、callable():判断一个对象是否能够调用
8、complex():求复数
9、dict():生成一个空字典
10、dir():返回对象的可调用属性
11、divmod():返回除法的商和余数
12、enumerate():返回列表的索引和元素
13、eval():可以把字符串形式的list,dict,set,tuple,再转换成其原有的数据类型
14、 exec():把字符串格式的代码,进行解义并执行
filter():对list、dict、set、tuple等可迭代对象进行过滤
filter(lambda x:x>10, [0,1,2,3,4,10,11,13,14])
#过滤出所有大于10的数
15、float(): 转成浮点
16、frozenset(): 把一个集合变成不可修改的
17、globals(): 打印全局作用域里的值
18、hex(): 返回一个10进制的16进制表示形式
19、id():查看对象的内存地址
20、isinstance():判断一个数据结构的类型,比如判断a是不是fronzenset, isinstance(a,frozenset) 返回 True or False
21、iter(): 把一个数据结构变成迭代器
22、map():map(lambda x:x**2,[1,2,3,43,45,5,6,]) 输出 [1, 4, 9, 1849, 2025, 25, 36]
23、max():求最大值
24、ord():返回ascii的字符对应的10进制数 ord(‘a’) 返回97
25、round() :可以把小数4舍5入成整数. round(10.15,1) 得10.2
26、sum():求和,a=[1, 4, 9, 1849, 2025, 25, 36],sum(a) 得3949
27、zip():可以把2个或多个列表拼成一个, a=[1, 4, 9, 1849, 2025, 25, 36],b = [“a”,”b”,”c”,”d”]
练习题:
1.输入用户名密码,正确后登录系统 ,打印
1. 修改个人信息
2. 打印个人信息
3. 修改密码
2.每个选项写一个方法
3. 当用户选择1时,提示用户选择要修改的字段,根据用户输入对相应字段进行修改
4.登录时输错3次退出程序
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
import os def print_info(info, username): ''' 打印个人信息 :param info: dict :param username: str :return: None ''' personal_info = info[username] user_menu = ''' ---------------------- 1.Name: {0} 2.Age : {1} 3.Job : {2} 4.Dept: {3} 5.Phone: {4} ---------------------- '''.format(username, personal_info[2], personal_info[3], personal_info[4], personal_info[5]) print(user_menu) def change_info(info, new_value, user, *args): ''' 修改个人信息,并且将修改后的数据存入字典中 :param info:dict :param current_value:str :param new_value: str :return: ''' num = args[0] print(type(num)) info[user][num] = new_value return info def save_file(current, new): f_old_name = "info.txt" f_new_name = "{}.new".format(f_old_name) f = open(f_old_name, "r", encoding="utf-8") f_new = open(f_new_name, "w", encoding="utf-8") for line in f: if current in line: new_line = line.replace(current, new) else: new_line = line f_new.write(new_line) os.rename(f_new_name,f_old_name) def main(): ''' 主程序 :return: ''' menu = ''' 1.打印个人信息 2.修改个人信息 3.修改密码 ''' info_dict = {} f = open("info.txt", "r", encoding="utf-8") info_data = f.readlines() f.close() # 将数据存入字典中,并且key为username,去掉首行 for line in info_data: line = line.strip() if not line.startswith("#"): line_li = line.split(",") info_dict[line_li[0]] = line_li count = 0 while count < 3: username = input("输入账户名:") password = input("输入密码:") if username in info_dict and password == info_dict[username][1]: print("welcome {}".format(username).center(50,"-")) while True: print(menu) choice = input("请选择编号>>>:").strip().lower() if choice == "q": break elif choice == "1": print_info(info_dict, username) continue elif choice == "2": person_num = [] for k,value in enumerate(info_dict[username],1): k = str(k) person_num.append(k) print(k,value) while True: # 不能修改名字 choice_num = input("选择您要修改的编号:") if choice_num == "1" or choice_num == "2": print("不能修改账户昵称或密码,请重新输入!!") continue elif choice_num in person_num: choice_num = int(choice_num) current_value = input("current value>>>:") if current_value == info_dict[username][choice_num-1]: new_value = input("new value>>>:") info_dict = change_info(info_dict, new_value, choice_num - 1,username) print(info_dict[username]) save_file(current_value,new_value) break else: print("current value error") continue else: print("您的输入不符合规范") continue elif choice == "3": while True: current_password = input("输入旧密码>>>:") if current_password == info_dict[username][1]: new_passwd = input("输入新密码>>>:") change_info(info_dict, new_passwd,username,1) save_file(current_password,new_passwd) print("更改成功,新密码为:{}".format(info_dict[username][1])) break else: print("密码错误,请重新输入") continue else: print("输入不符合规范,请重新输入") continue count = 0 else: count += 1 print("账户名或密码错误,请重新输入") continue