python代码练习1

练习1:评价成绩

while True:
    a = input("请输入成绩(输入z退出):")
    if a.isdigit():
        a = int(a)
        if a > 100:
            print("请输入0到100的数字")
        elif a>=90:
            print("优秀")
        elif a>=70:
            print("良好")
        elif a>=60:
            print("及格")
        elif a>=0:
            print("不及格")
        else:
            print("请输入0到100的数字")
    elif a=="z":
        break
    else:
        print("请输入0到100的数字")
print("程序退出")

练习2:判断每个月的天数

while True:
    a = input("请输入月份(输入z退出程序)")
    if a.isdigit():
        a = int(a)
        if (a == 1 or a==3 or a==5 or a==7 or a==8 or a==10 or a==12):
            print(a,'月有31天')
        elif (a== 4 or a==6 or a==9 or a==11):
            print(a,'月有30天')
        elif a==2:
            var2=1
            while var2==1:
                b = input("请输入年份")
                if b.isdigit():
                    b = int(b)
                    if b%4==0 and b%100!=0 or b%400==0:
                        print(b,'年',a,'月有29天')
                        break
                    else:
                        print(b,'年',a,'月有28天')
                        break
                else:
                    print("输入错误")
    elif a=='z':
        break
print('程序结束')

练习3:猜数字游戏

import random

while True:
    a = random.randint(1,100)
    print("随机数已生成" + str(a))
    c = "1"
    d = "100"
    while True:
        b = input("请猜测随机数，范围( " + c + " — " + d + " ):")
        if b.isdigit():
            b = int(b)
            if b>a and b<=int(d):
                print("你输入的数字太大")
                d = str(b-1)
            elif b<a and b>=int(c):
                print("你输入的数字太小")
                c = str(b+1)
            elif b==a:
                print("恭喜你猜中了")
                break
            else:
                print("输入错误")
        else:
            print("输入有误")