为什么Python的原始字符串文字不能以单个反斜杠结尾? [英] Why can't Python's raw string literals end with a single backslash?

问题描述

从技术上讲，如中所述，任意数量的反斜杠文档.

>>> r'\'
  File "<stdin>", line 1
    r'\'
       ^
SyntaxError: EOL while scanning string literal
>>> r'\\'
'\\\\'
>>> r'\\\'
  File "<stdin>", line 1
    r'\\\'
         ^
SyntaxError: EOL while scanning string literal

似乎解析器可以将原始字符串中的反斜杠视为常规字符(这不是原始字符串的全部含义吗?)，但是我可能缺少明显的东西.

It seems like the parser could just treat backslashes in raw strings as regular characters (isn't that what raw strings are all about?), but I'm probably missing something obvious.

推荐答案

原因在本部分中以粗体突出显示的部分进行了解释:

The reason is explained in the part of that section which I highlighted in bold:

字符串引号可以使用 反斜杠，但反斜杠仍然存在 在字符串中；例如，r"\""是一个 由两个组成的有效字符串文字 字符:一个反斜杠和一个双 引用; r"\"不是有效的字符串 文字(即使原始字符串也不能结束 以奇数个反斜杠表示). 具体来说，原始字串无法结束 在一个反斜杠中(因为 反斜杠将逃避以下内容 引号字符).另请注意， 单个反斜杠后跟换行符 被解释为这两个字符 作为字符串的一部分，而不是一行 延续.

String quotes can be escaped with a backslash, but the backslash remains in the string; 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 string cannot end in a single backslash (since the backslash would escape the following quote character). Note also that a single backslash followed by a newline is interpreted as those two characters as part of the string, not as a line continuation.

因此原始字符串不是100％原始的，仍然存在一些基本的反斜杠处理.

So raw strings are not 100% raw, there is still some rudimentary backslash-processing.

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