import math import datetime def guess_number(answer): while True: guess = int(input("请猜一个数字: ")) if guess == answer: print("恭喜你，猜对了！") break elif guess > answer: print("太大了，请猜小一点。") else: print("太小了，请猜大一点。") def factorial_sum(n): sum = 0 for i in range(1, n+1): fact = math.factorial(i) print(f"{i}! = {fact}") sum += fact print(f"{n}! 的和为 {sum}") def case_conversion(s): result = "" for c in s: if c.isupper(): result += c.lower() elif c.islower(): result += c.upper() else: result += c print(result) def calculate_age_and_zodiac(year): current_year = datetime.datetime.now().year age = current_year - year zodiacs = ["猴", "鸡", "狗", "猪", "鼠", "牛", "虎", "兔", "龙", "蛇", "马", "羊"] zodiac_index = (year - 1900) % 12 zodiac = zodiacs[zodiac_index] print(f"你的年龄是{age}岁，生肖是{zodiac}。")给这个代码增加选择功能

好的，我可以为这个代码增加一个选择功能，让用户选择要执行的函数。下面是修改后的代码：

import math 
import datetime 

def menu():
    print("请选择要执行的操作：")
    print("1. 猜数字游戏")
    print("2. 求阶乘和")
    print("3. 大小写互换")
    print("4. 计算年龄和生肖")
    choice = input("请输入选择的数字：")
    return int(choice)

def guess_number(answer):
    while True:
        guess = int(input("请猜一个数字: "))
        if guess == answer:
            print("恭喜你，猜对了！")
            break
        elif guess > answer:
            print("太大了，请猜小一点。")
        else:
            print("太小了，请猜大一点。")

def factorial_sum(n):
    sum = 0
    for i in range(1, n+1):
        fact = math.factorial(i)
        print(f"{i}! = {fact}")
        sum += fact
    print(f"{n}! 的和为 {sum}")

def case_conversion(s):
    result = ""
    for c in s:
        if c.isupper():
            result += c.lower()
        elif c.islower():
            result += c.upper()
        else:
            result += c
    print(result)

def calculate_age_and_zodiac(year):
    current_year = datetime.datetime.now().year
    age = current_year - year
    zodiacs = ["猴", "鸡", "狗", "猪", "鼠", "牛", "虎", "兔", "龙", "蛇", "马", "羊"]
    zodiac_index = (year - 1900) % 12
    zodiac = zodiacs[zodiac_index]
    print(f"你的年龄是{age}岁，生肖是{zodiac}。")

while True:
    choice = menu()
    if choice == 1:
        answer = int(input("请输入答案数字："))
        guess_number(answer)
    elif choice == 2:
        n = int(input("请输入一个整数："))
        factorial_sum(n)
    elif choice == 3:
        s = input("请输入一个字符串：")
        case_conversion(s)
    elif choice == 4:
        year = int(input("请输入出生年份："))
        calculate_age_and_zodiac(year)
    else:
        print("选择无效，请重新选择。")

现在，当用户运行程序时，会先出现一个菜单，用户可以选择要执行的函数。根据用户的选择，程序会执行对应的函数。如果选择无效，程序会提示用户重新选择。