九九乘法表金字塔型

要输出九九乘法表金字塔型，可以在右对齐的基础上，再加上一些空格来实现。具体代码如下：

for i in range(1, 10):
    for j in range(1, i+1):
        print("{:2d} x{:2d} ={:2d}".format(j, i, i*j), end="  ")
    print(" "*(18-3*i), end="")
    for j in range(1, i+1):
        print("{:2d} x{:2d} ={:2d}".format(j, i+1, (i+1)*j), end="  ")
    print()

在输出完每一行的乘法表后，再输出一些空格，使得下一行的第一个数能够与上一行的中间对齐。其中，18是每行的总长度，3是每个乘法表项的长度。效果如下：

 1 x 1 = 1                                       1 x 2 = 2  
 1 x 2 = 2   2 x 2 = 4                             1 x 3 = 3   2 x 3 = 6  
 1 x 3 = 3   2 x 3 = 6   3 x 3 = 9                 1 x 4 = 4   2 x 4 = 8   3 x 4 =12  
 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  
 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  
 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 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 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