Re: Correct syntax for pathological re.search()

On 2024-10-07 14:35, Michael F. Stemper via Python-list wrote:

I'm trying to discard lines that include the string "\sout{" (which is TeX, for
those who are curious. I have tried:
    if not re.search("\sout{", line):
    if not re.search("\sout\{", line):
    if not re.search("\sout{", line):
    if not re.search("\sout\{", line):
 But the lines with that string keep coming through. What is the right syntax to
properly escape the backslash and the left curly bracket?
 

String literals use backslash is an escape character, so it needs to be escaped, or you need to use a "raw" string.
However, regex also uses backslash as an escape character.
That means that a literal backslash in a regex that's in a plain string literal needs to be doubly-escaped, once for the string literal and again for the regex.