vote/unvote api calls

@issues_bp.route('/<int:issue_id>/vote/', methods=['POST'])
@login_required
def voting(issue_id):
    issue = Issue()
    vote_filter = db.session.query(Vote). \
        filter(and_(Vote.target_id == issue_id, Vote.author_id == g.user.id)
               ).all()
    if vote_filter:
        return jsonify({'msg': 'Already voted'})
    else:
        vote = Vote(author=g.user, vote=True, target=issue)
        vote.target_id = issue_id
        db.session.add(vote)
        db.session.commit()
        return jsonify({}), 201


@issues_bp.route('/<int:issue_id>/unvote/', methods=['DELETE'])
@login_required
def remove_vote(issue_id):
    vote_filter = db.session.query(Vote). \
        filter(and_(Vote.target_id == issue_id, Vote.author_id == g.user.id))
    result = vote_filter.delete(synchronize_session='fetch')
    if result:
        db.session.commit()
        return jsonify({'status': 0})
    else:
        db.session.rollback()
        return jsonify({'msg': 'vote not found', 'status': 1})