Python一段程序中为何结果有的是‘ ‘ 有的是“ ”？

Question

formatter = "%r %r %r %r"

print formatter % (

    "I had this thing.",

    "That you could type up right.",

    "But it didn't sing.",

    "So I said goodnight."

)

上边这段程序结果如下：

'I had this thing.' 'That you could type up right.' "But it didn't sing." 'So I said goodnight.'

为什么有的是‘     ’有的是‘’‘’？

Answer 1

因为"But it didn't sing."  这句中间有单引号啊