re.sub(): replace longest match instead of leftmost match?

[John Gordon]

In <mailman.3737.1324054637.27778.python-list at python.org> Devin Jeanpierre <jeanpierreda at gmail.com> writes:

> You could use re.finditer to find the longest match, and then replace
> it manually by hand (via string slicing).

> (a match is the longest if (m.end() - m.start()) is the largest --
> so, max(re.finditer(...), key=3Dlambda m: (m.end() =3D m.start()))

I ended up doing something similar:

    # find the longest match
    longest_match = ''
    for word in re.findall('((0000:?)+)', ip6):
        if len(word[0]) > len(longest_match):
            longest_match = word[0]

    # if we found a match, replace it with a colon
    if longest_match:
      ip6 = re.sub(longest_match, ':', ip6, 1)

Thanks!

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"