用python实现九九乘法表

#for循环实现99乘法表
for i in range(1,10):   
    for a in range(1,10):  #横向打印
        print('%d*%d=%d'%(a,i,i*a),end=' ')
        if i==a:
            print('')
            break
-------------------------------------------------------
1*1=1 
1*2=2 2*2=4 
1*3=3 2*3=6 3*3=9 
1*4=4 2*4=8 3*4=12 4*4=16 
1*5=5 2*5=10 3*5=15 4*5=20 5*5=25 
1*6=6 2*6=12 3*6=18 4*6=24 5*6=30 6*6=36 
1*7=7 2*7=14 3*7=21 4*7=28 5*7=35 6*7=42 7*7=49 
1*8=8 2*8=16 3*8=24 4*8=32 5*8=40 6*8=48 7*8=56 8*8=64 
1*9=9 2*9=18 3*9=27 4*9=36 5*9=45 6*9=54 7*9=63 8*9=72 9*9=81 
--------------------------------------------------------
#while循环实现99乘法表
i = 1
while i <= 9:      #该乘法表横向打印
    j = 1
    while j <= i:              #先一个大循环，把所有小循环实现完成，在进行下一次大循环。若小循环的条件不能满足，则下列的 j+=1不成立。进入下一次循环
        print('%d X %d = %d' % (j,i,i*j),end = '  ') 
        j += 1
    print('')
    i += 1
--------------------------------------------------------
1 X 1 = 1  
1 X 2 = 2  2 X 2 = 4  
1 X 3 = 3  2 X 3 = 6  3 X 3 = 9  
1 X 4 = 4  2 X 4 = 8  3 X 4 = 12  4 X 4 = 16  
1 X 5 = 5  2 X 5 = 10  3 X 5 = 15  4 X 5 = 20  5 X 5 = 25  
1 X 6 = 6  2 X 6 = 12  3 X 6 = 18  4 X 6 = 24  5 X 6 = 30  6 X 6 = 36  
1 X 7 = 7  2 X 7 = 14  3 X 7 = 21  4 X 7 = 28  5 X 7 = 35  6 X 7 = 42  7 X 7 = 49  
1 X 8 = 8  2 X 8 = 16  3 X 8 = 24  4 X 8 = 32  5 X 8 = 40  6 X 8 = 48  7 X 8 = 56  8 X 8 = 64  
1 X 9 = 9  2 X 9 = 18  3 X 9 = 27  4 X 9 = 36  5 X 9 = 45  6 X 9 = 54  7 X 9 = 63  8 X 9 = 72  9 X 9 = 81 

print('hello',end='')
print('world')

print('hello',end='    ')
print('world')

print('hello',end='!')
print('world')
----------------------------------------------------------
helloworld
hello    world
hello!world

for i in range(1,3):
    print('%d X %d = %d' % (i,2,i*2),end = '  ')
print('') #用来换行

for i in range(1,4):
    print('%d X %d = %d' % (i,3,i*3),end = '  ') 
-------------------------------------------------
1 X 2 = 2  2 X 2 = 4  
1 X 3 = 3  2 X 3 = 6  3 X 3 = 9  

end=‘ ’用来控制在正常循环时不换行
print(‘’)用来在a=i时，进行下一行的切换
break 用来在a=i时，进行打断该次内循环，进行下一次的外循环