循环判断示例

九九乘法表：
完整版打印

for i in range(1,10):
    for j in range(1,10):
        print('%s*%s=%s'%(i,j,i*j))
    print('\n')
'''
i = 1
while i<10:
    j = 1
    while j<10:
        print('%s*%s=%s\t'%(j,i,i*j),end='')
        j+=1
    i+=1
    print('\n')
'''

正三角打印

i = 1
while i<10:
    j = 1
    while j<=i:
        print('%s*%s=%s\t'%(j,i,i*j),end='')
        j+=1
    i+=1
    print('\n')

01_九九乘法表.jpg

if elif例子：

salary = int(input('输入工资：'))
if salary<3000:
    print('屌丝......')
elif salary<5000:
    print('土鳖......')
elif salary<8000:
    print('温饱......')
elif salary<12000:
    print('普通......')
elif salary<20000:
    print('小康......')
else:
    print('土豪......')

判断变量名是否正确：

def f(s):
    if s[0].isdigit():
        return('不符合')
    else:
        for i in s:
            if (i.isalpha())or(i.isdigit())or(i=='_'):
                continue
            else:
                return('不符合')
        return('符合')
print(f(input('请输入字符串：')))

猜拳游戏：

import random

while True:
    computer = random.randint(0,2)
    player = int(input('请输入：剪刀(0)  石头(1)  布(2):'))

    if player!=0 and player!=1 and player!=2:
        print('输入的数字不符合要求，请重新选择')
    else:
        if (computer==0 and player==1)or(computer==1 and player==2)or(computer==2 and player==0):
            print('恭喜你，赢啦......')
        elif computer==player:
            print('平手......')
        else:
            print('输啦......')
        answer = input('****还玩吗(Y/N)?****')
        if answer!='Y':
            break

        print('计算机选择的是%s,用户选择的是%s.'%(computer,player))

print('game over......')