import random
# 1.将登陆注册的代码改成函数的写法
def a(): print("欢迎来到登录界面") name = input("请输入用户名:") password = input("请输入密码:") a = {name: password} for i, j in database.items(): if a == {i: j}: print("登录成功") if a != {i: j}: print("账号或密码错误,请重新输入") def b(): while True: print("欢迎来到注册界面\n不需要注册输入:0") name = input("请输入用户名:") if name == "0": print("退出注册\n") break password = input("请输入密码:") for i in database.keys(): if name == i: print("此账户已被注册\n") break if name != i: database.setdefault(name, password) print("注册成功") break database = {" ": " "} while True: choice = int(input("网站登录界面\n1:登录\n2:注册\n3:退出\n请选择:")) if choice == 1: a() if choice == 2: b() if choice == 3: print("退出成功") break # 2.设计一个函数,统计一个字符串中出现频率最高的字符(单个符号)及其出现次数 str1 = input("请输入:") def hanshu(): top = 0 count = 0 num = 0 while num < len(str1): if count < str1.count(str1[num]): count = str1.count(str1[num]) top = str1[num] num += 1 print("频率最高的字符为", '\"',