human
Solve the following python programming problem given the following code:
@task
def get_authors():
assistant
#Here is the Python program you requested.

    """Get the list of authors since the previous release
    Returns the list in alphabetical order by last name.  Authors who
    contributed for the first time for this release will have a star appended
    to the end of their names.
    Note: it\s a good idea to use ./bin/mailmap_update.py (from the base sympy
    directory) to make AUTHORS and .mailmap up-to-date first before using
    this. fab vagrant release does this automatically.
    """
    def lastnamekey(name):
        '\n                                Sort    key    to    sort    by    last    name\n\n                                Note,    we    decided    to    sort    based    on    the    last    name,    because    that    way    is\n                                fair.    We    used    to    sort    by    commit    count    or    line    number    count,    but    that\n                                bumps    up    people    who    made    lots    of    maintenance    changes    like    updating\n                                mpmath    or    moving    some    files    around.\n                                '
        text = unicode(name.strip().split()[(-1)], encoding='utf-8').lower()
        return unicodedata.normalize('NFKD', text).encode('ascii', 'ignore')
    old_release_tag = get_previous_version_tag()
    with cd('/home/vagrant/repos/sympy'):
        with hide('commands'):
            releaseauthors = set(run('git    --no-pager    log    {tag}..    --format="%aN"'.format(tag=old_release_tag)).strip().split('\n'))
            priorauthors = set(run('git    --no-pager    log    {tag}    --format="%aN"'.format(tag=old_release_tag)).strip().split('\n'))
            releaseauthors = {name.strip() for name in releaseauthors if name.strip()}
            priorauthors = {name.strip() for name in priorauthors if name.strip()}
            newauthors = (releaseauthors - priorauthors)
            starred_newauthors = {(name + '*') for name in newauthors}
            authors = ((releaseauthors - newauthors) | starred_newauthors)
            return (sorted(authors, key=lastnamekey), len(releaseauthors), len(newauthors))