Pretext: escape backslashes in regex

[Alex-Jordan]

With Python 3.12.2, running pretext produces these warnings:

/Users/alex.jordan/pretext/pretext/pretext.py:2524: SyntaxWarning: invalid escape sequence '\*'
  elif len(re.findall('^[ ]{2},\*apt} #([a-j]+?) ', line)) > 0:
/Users/alex.jordan/pretext/pretext/pretext.py:2526: SyntaxWarning: invalid escape sequence '\*'
  chapter_number = brf_to_num(re.findall("^[ ]{2},\*apt} #([a-j]+?) ", line)[0])

The intent here is to escape the asterisk in the regex context. But first the backslash must be escaped or python will produce that warning. I'm guessing might \* become *, and this regex was not working as intended. Or maybe \* becomes \*. But this change should have things working as intended and make those warnings go away.

[rbeezer]

I think this may be dead code, for chunking a braille BRF into chapters.

So did you get these warnings while doing something else? You weren't building braille were you? Is it simple a product of using 3.12.

Inclined to merge with very little testing...

[Alex-Jordan]

I think it is just because I upgraded python and it's reporting this where previous python versions sweep it under the rug. Not building braille, building webwork. But python is trying to parse everything in pretext.py, catches this, and gives those warnings.

[rbeezer]

it's reporting this where previous python versions sweep it under the rug

As suspected. Thanks for the confirmation. Merged.

Pinging @alexeikolesnikov since he is interested in this code.