习题8：打印打印

formatter = "%r %r %r %r"
print formatter % (1, 2, 3, 4)
print formatter % ("one", "two", "three", "four")
print formatter % (True, False, False, True)
print formatter % (formatter, formatter, formatter, formatter)
print formatter % ("I had this thing.",
"That you could type up right.",
"But it didn't sing.",
"So I said goodnight.")

运行结果如下：

正如作者在加分习题所问——“注意最后一行程序中既有单引号又有双引号，你觉得它是如何工作的？”

这也正是我好奇的地方。