方法一：
for i in range(1,10):
    for j in range(1,i+1):
        print( '%d X %d = %d' % (j,i,i*j),end = '  ' )
    print('  ')

方法二：
for i in range (1,10):
    for j in range(1,10):
        print('%d X %d = %d' % (j,i,i*j),end = '  ')
        if i==j:
            print(' ')
            break

方法三：
i = 1
while i <= 9:
    j = 1
    while j <= i:
        print('%d X %d = %d' % (j,i,i*j),end = '  ')
        j += 1
    print(' ')
    i += 1