I'm trying to use a Python regex to find a mathematical expression in a string. The problem is that the forward slash seems to do something unexpected. I'd have thought that [\w\d\s+-/*]* would work for finding math expressions, but it finds commas too for some reason. A bit of experimenting reveals that forward slashes are the culprit. For example:
>>> import re
>>> re.sub(r'[/]*', 'a', 'bcd')
'abacada'
Apparently forward slashes match between characters (even when it is in a character class, though only when the asterisk is present). Back slashes do not escape them. I've hunted for a while and not found any documentation on it. Any pointers?