【Pthon入门学习】99乘法表

学习知识点：

1. string.join(seq): 以string字符串作为分隔符，将seq的所有元素拼接成一个新的字符串

  1 s = ['%d * %d = %d' % (y, 4, 4*y) for y in range(1, 5)]
  2 print('\t'.join(s))
  3 

2. list的赋值可以采用表达式

  1 s = ['%d * %d = %d' % (y, 4, 4*y) for y in range(1, 5)]

下面是99乘法表的拆分过程

1. 打印第i行

  1 i = 5
  2 s = ['%d * %d = %d' % (y, i, y * i) for y in range(1, i+1)]
  3 print('\t'.join(s))

2. 打印多行

  1 i = 1
  2 s = ['%d * %d = %d' % (y, i, y * i) for y in range(1, i+1)]
  3 print('\t'.join(s))
  4 i = 2
  5 s = ['%d * %d = %d' % (y, i, y * i) for y in range(1, i+1)]
  6 print('\t'.join(s))
  7 i = 3
  8 s = ['%d * %d = %d' % (y, i, y * i) for y in range(1, i+1)]
  9 print('\t'.join(s))

3. 再次借助join的方式实现

  1 i = 1
  2 s = ['%d * %d = %d' % (y, i, y * i) for y in range(1, i+1)]
  3 # print('\t'.join(s))
  4 i = 2
  5 s = ['%d * %d = %d' % (y, i, y * i) for y in range(1, i+1)]
  6 # print('\t'.join(s))
  7 i = 3
  8 s = ['%d * %d = %d' % (y, i, y * i) for y in range(1, i+1)]
  9 # print('\t'.join(s))
 10
 11 print('\n'.join('\t'.join(s) for i in range(1, 10)))
 12 #将s替换成表达式后即为99乘法表
 13 print('\n'.join('\t'.join(['%d * %d = %d' % (y, i, y * i) for y in range(1, i+1)]) for i in range(1, 10)))
 14
 15