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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def user_structure(user, site):
 """ An user structure. """

    full_name = user.get_full_name().split()
    first_name = full_name[0]
    try:
        last_name = full_name[1]
    except IndexError:
        last_name = ''
    return {'userid': user.pk,
            'email': user.email,
            'nickname': user.get_username(),
            'lastname': last_name,
            'firstname': first_name,
            'url': '%s://%s%s' % (
                PROTOCOL, site.domain,
                user.get_absolute_url())}