Python语言编写有趣练习题！

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')
        break
    else:
        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 += 1
    if 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 re

def 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'
                break
            else:
                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)**3
            if formula <= 0:
                lst_con += char[(x) % len(char)]
            else:
                lst_con += ' '
       lst.append(lst_con)
       allChar += lst
   print('\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()