Consecutive, conflicting regex substitutions

Question

I've tried this for the italics:

r = re.compile(r"(\*[^ ]+\*)")
r.sub(r'<i>"\1"</i>', foo)

but it doesn't work, as I am sure anyone in the regex know will see right away.

Answer 1

It would easily work, if you switch the order of substitutions. Handling the bold case first would prevent italics taking over.

Answer 2

Your regex and substitution need a few tweaks.

r = re.compile(r"(\*[^ ]+\*)")

You are capturing a bit too much here -- the asterisks are preserved in \1.

r.sub(r'<i>"\1"</i>', foo)

You are substituting a bit too much here -- the double-quote marks are included in the substitution. Example:

r.sub(r'<i>"\1"</i>', '*foo*')  # -> '<i>"*foo*"</i>'

Try something like this:

foo = '***foo***'
bold = re.compile(r'''\*\*([^ ]+)\*\*''')
ital = re.compile(r'''\*([^ ]+)\*''')

ital.sub(r'''<i>\1</i>''', bold.sub(r'''<b>\1</b>''', foo)) # '<b><i>foo</i></b>'