Python basics lesson 5 notes and homework

Condition control

if statement

# if 条件表达式:
#     代码块
a = False
if a:
    print('True')

if-else statement

a = False
if a:
    print('True')
else:
    print('False')

if-elif-else statement

value = 30000
if value >= 30000:
    print('有钱任性')
elif value >= 20000:
    print('有钱真好')
elif value >= 10000:
    print('工资还说的过去')
else:
    print('苦')

input() function

• This function is used to get user input
• After input() is called, the program will immediately pause, waiting for user input
• After the user enters the content, the program will continue to execute downward after clicking Enter
• After the user's input is completed, the content entered will be returned in the form of return value

Loop control

while statement

# 语法
# while 条件表达式:
#     代码块
# else:
#     代码块

break和continue

• break can be used to immediately exit the loop statement, including the else statement
• continue is used to skip the original loop

operation

Find the number of daffodils within 1000

for i in range(100, 1000):
    m = i // 100    #整除获得百位数
    n = (i % 100) // 10        #十位数
    k = i % 10       #个位数
    if m**3 + n ** 3 + k ** 3 == i:
        print(i)

---

Get any number entered by the user and determine whether it is a prime number?

num = int(input("请输入一个数字: "))
is_ok = True
count = 2
if num > 1:
    while is_ok:
        if count >= num:
            is_ok = False
        else:
            if (num % count) == 0:
                print(num, "不是质数")
                print(f"{count} 乘于 {num // count} = {num}")
                break
        count += 1
    else:
        print(f"{num}是质数")
else:
   print(f"{num}不是质数")

---

Guessing game:

• Punch player: manual input computer: random input
• Judging the winner: the player wins the computer wins the draw

import random

while True:
    c = random.randint(1, 3)
    c_str = ''
    print("**************************************************")
    u = int(input("1. 石头、\t2. 剪刀\t3. 布\t0. 退出\t请选择:"))
    u_str = ''
    if u == 0:
        break
    else:
        if c == 1:
            c_str = "石头"
        elif c == 2:
            c_str = "剪刀"
        else:
            c_str = "布"
        if u == 1:
            u_str = "石头"
        elif u == 2:
            u_str = "剪刀"
        else:
            u_str = "布"
        print(f"电脑: {c_str}")
        print(f"玩家: {u_str}")
        if c == u:
            print("平局")
        elif u - c == -1 or u - c == 2:
            print("恭喜你赢了")
        else:
            print("你输了")
    input("任意键从来")
print("游戏结束")