1. 登录作业：

写一个登录程序，登录成功之后，提示XXX欢迎登录，登录失败3次后，提示账户锁定

username = "admin"
passwd = "1234"
count =0
_username = str(input("请输入用户名："))
while count < 3:_passwd = str(input("请输入密码："))if _username == username and _passwd == passwd :print(username,'欢迎登录')breakelse:if count < 2:print("输入错误，请检查后再一次输入")else:print("由于你输入的错误次数过多，登录已经被锁定")count += 1if count == 3:f =open("lock.txt","a",encoding="utf-8")f.write("\n")f.write(_username)

2. 判断密码是否安全

设计一个密码是否安全的检查函数。
密码安全要求：
1.要求密码为6到20位，
2.密码只包含英文字母和数字

import redef check_code(code):while True:if len(code) < 6 or len(code) > 20:return '密码长度不足6-20位'break  # 不用break将是死循环else:for i in code:s = ord(i) in range(97, 123) or ord(i) in range(65, 91) or ord(i) in range(48, 59)if not s:return '密码只能包含英文字母和数字，不能填入其他字符'breakelse:return '密码安全'print(check_code('555555'))

3. 有1、2、3、4个数字，能组成多少个互不相同且无重复数字的三位数？都是多少？

分析：
- 可填在百位、十位、个位的数字都是1、2、3、4
- 组成所有的排列后再去掉不满足条件的排列

for i in range(1,5):for j in range(1,5):for k in range(1,5):if( i != k ) and (i != j) and (j != k):print (i,j,k)

4. 打印楼梯，同时在楼梯上方打印两个笑脸

print("^_^",end='')
for i in range(1,11):for j in range(1,i):print('===',end='\t')print()

延伸一下，很有趣！

import turtle# 画矩形立方体
def draw_cube(i):turtle.begin_fill()turtle.color("black")turtle.goto(i, i * 3)turtle.goto(100 + i, i * 3)turtle.goto(100 + i, 20 + i * 3)turtle.goto(i, 20 + i * 3)turtle.goto(i, i * 3)turtle.end_fill()turtle.penup()turtle.goto(i, 20 + i * 3)turtle.pendown()turtle.goto(10 + i, 30 + i * 3)turtle.goto(110 + i, 30 + i * 3)turtle.goto(110 + i, 10 + i * 3)turtle.goto(100 + i, i * 3)turtle.penup()turtle.goto(100 + i, 20 + i * 3)turtle.pendown()turtle.goto(110 + i, 30 + i * 3)# 画笑脸
def draw_smile_face(x, y):turtle.goto(x + 50, y)turtle.pensize(1.5)# 脸部turtle.circle(20)turtle.penup()# 眼睛turtle.goto(x + 40, y + 20)turtle.pendown()turtle.begin_fill()turtle.color("black")turtle.circle(3)turtle.end_fill()turtle.penup()turtle.goto(x + 60, y + 20)turtle.pendown()turtle.begin_fill()turtle.color("black")turtle.circle(3)turtle.end_fill()turtle.penup()# 嘴巴turtle.goto(x + 45, y + 10)turtle.pendown()turtle.right(90)turtle.pensize(2)turtle.circle(5, 180)def main():turtle.speed(2)for i in range(0, 100, 10):draw_cube(i)
draw_smile_face(100, 300)
turtle.hideturtle()
time.sleep(3)main()

5. 打印心形

import time
sentence = "Dear, I love you forever!"
for char in sentence.split():allChar = []for y in range(12, -12, -1):lst = []lst_con = ''for x in range(-30, 30):formula = ((x*0.05)**2+(y*0.1)**2-1)**3-(x*0.05)**2*(y*0.1)**3if formula <= 0:lst_con += char[(x) % len(char)]else:lst_con += ' 'lst.append(lst_con)allChar += lstprint('\n'.join(allChar))time.sleep(1)

6. 9*9乘法表

for i in range(1,10):for j in range(1,i+1):print(str(j) + str("*") + str(i)+"=" + str(i*j),end="\t")print()