为什么 raw 的 r 禁止转义会失效呢

原生字符串的结尾不能是 “反斜杠” + “引号” 。
可以写成 r'D:\下载\Temp\official' + '\\'

后边的引号被转义了
另： https://stackoverflow.com/questions/2953834/windows-path-in-python

根据 python 文档：Even in a raw literal, quotes can be escaped with a backslash, but the backslash remains in the result; for example, r"\"" is a valid string literal consisting of two characters: a backslash and a double quote; r"\" is not a valid string literal (even a raw string cannot end in an odd number of backslashes). Specifically, a raw literal cannot end in a single backslash (since the backslash would escape the folowing quote character). Note also that a single backslash followed by a newline is interpreted as those two characters as part of the literal, not as a line continuation.

只有最后一个反斜杠会失效

谢谢楼上的各位

这是为了让 syntax 简单，把 raw 放到 semantic 层来实现。