详细的正则表达式注释中的连字符会导致错误-Hypheninverboseregexcommentcauseserror

7  

According to the documentation (emphasis mine):

根据文件(强调我的):

re.X
re.VERBOSE

This flag allows you to write regular expressions that look nicer. Whitespace within the pattern is ignored, except when in a character class or preceded by an unescaped backslash, and, when a line contains a '#' neither in a character class or preceded by an unescaped backslash, all characters from the leftmost such '#' through the end of the line are ignored.

此标志允许您编写看起来更好的正则表达式。模式中的空格被忽略,除非在字符类中或前面有未转义的反斜杠,并且当一行中的字符类中既没有'#'也没有未转义的反斜杠时,最左边的所有字符都是'# '到最后一行被忽略了。

Basically, you cannot have comment inside a character class, and whitespace inside character class is considered significant.

基本上,您不能在字符类中进行注释,并且字符类中的空格被认为是重要的。

Since # is inside character class, it does not function as comment, and everything inside the character class is parsed as part of the character class without exception (even the new line character is parsed as part of the character class). The error is thrown due to n-c being invalid character range.

由于#在字符类中,因此它不作为注释起作用,并且字符类中的所有内容都被解析为字符类的一部分而没有异常(即使新行字符被解析为字符类的一部分)。由于n-c是无效字符范围而引发错误。

Valid way to write the expression would be:

编写表达式的有效方法是:

valid = re.compile(r'[^\uFFFE\uFFFF]   # non-characters', re.VERBOSE)

Here is one suggestion on how to comment when you want to explain a lengthy character class:

以下是关于如何在需要解释冗长字符类时进行注释的建议:

r'''
# LOTS is for foo
# _ is a special fiz
# OF-LITERAL is for bar
[^LOTS_OF-LITERAL]
'''

-1  

Comments don't always play nice in regular expressions, and it looks like your regex engine is parsing the hyphen as part of the regular expression. You can't rely on comments not getting parsed here. This is a good thing to find out before implementing this code.

注释在正则表达式中并不总是很好用,看起来你的正则表达式引擎正在解析连字符作为正则表达式的一部分。您不能依赖于未在此处解析的评论。在实现此代码之前,这是一件好事。