python 实例

# 四位验证码

"""四位数验证码"""
code=""
for i in range(4):
    print(i)
    index = random.randrange(4)  #0-3 中随机取一个数
    if index != i and index + 1 != i:
        code +=chr(random.randint(97,122))  #小写字母
    elif index + 1 == i:
        code +=chr(random.randint(65,90))   #大写字母
    else:
        code +=str(random.randint(1,9))
print(code)

 登录写入日志，读取日志

#显示功能界面
def show():
    print(" q 退出登录 
 1 查看登录日志" )
    while True:
        code = input("输入选项：")
        if code == "q":
            break
        elif code == "1":
            read_log()
            break
        else:
            print("输入错误重新输入")
#登录日志查看
import time
def write_log(username):
    """写入日志"""
    """打开一个文件"""
    """日志格式 用户名 ： 日期 ，登录是否成功"""
    with open('info', 'a') as f:
        login_rizhi = "用户名:{} 登录时间: {} 
".format(username,time.strftime('%Y-%m-%d %H:%M:%S',time.localtime(time.time())))
        f.write(login_rizhi)

def read_log():
    """读取日子文件"""
    with open('info','r') as f:
        while True:
            line = f.readline()
            if line == "":
                break
            print(line)
user_passwd = {"xiao":"123","long":"1234","cui":"34"}
def login():
    """用户登录 """
    """进行判断"""
    username = input("输入用户名：")
    if username in user_passwd.keys():
        passwd = input("输入密码:")
        if passwd == user_passwd[username]:
            print("登录成功")
            write_log(username)
            show()
        else:
            print("密码错误")
    else:
        print("用户名不存在")
login()

查看是不是闰年

while True:
    code=int(input("输入年份："))
    if code == 0:
        break
    elif (code % 4 == 0 and code % 100 !=0) or code % 400 == 0:
        print("{} 年时闰年".format(code))
    else:
        print("{} 年不是闰年".format(code))

 画五角星

#画五角星
import turtle
import time
turtle.forward(100)
turtle.right(144)
turtle.forward(100)
turtle.right(144)
turtle.forward(100)
turtle.right(144)
turtle.forward(100)
turtle.right(144)
turtle.forward(100)
time.sleep(2)