打印九九乘法表的两种方法

#1.for循环
rows,cols = xrange(1,10),xrange(1,10)
row,col = 1,1
for row in rows:
   for col in cols:
      if col <= row:
         print ‘%d*%d=%d\t‘ % (col,row,col*row),  #\t代表tab键, 逗号确保同rows在同一行
   print  #打印空格，确保同col在同一列 

可以简化为:
for rows in xrange(1,10):
   for cols in xrange(1,10):
      if cols <= rows:
         print ‘%d*%d=%d\t‘ % (cols,rows,cols*rows),
   print 

#2.while循环
row = 1
while row <= 9:
    col = 1
    while col <= row:
       print ‘%s*%s=%s\t‘ % (col,row,col*row),
       col += 1
    row += 1
    print