def replacement(match):
    groupdict = match.groupdict()
    is_url = groupdict.get('url')
    if is_url:
        return is_url
    return ('\\' + groupdict['markdown'])
def replacement(match):
    groupdict = match.groupdict()
    is_url = groupdict.get('url')
    if is_url:
        return is_url
    return ('\\' + groupdict['markdown'])