def get_paginated_list_filter(klass, url, start, limit, query):
    start = int(start)
    limit = int(limit)
    results = klass

    obj = {}

    if start == 1:
        obj['previous'] = ''
    else:
        start_copy = max(1, start - limit)
        limit_copy = limit
        obj['previous'] = url + '?query=%s&start=%d&limit=%d' % (query, start_copy, limit)

    # make next url
    if start + limit < 1:
        obj['next'] = ''
    else:
        start_copy = start + limit
        obj['next'] = url + '?query=%s&start=%d&limit=%d' % (query, start_copy, limit)

    obj['results'] = results[(start - 1):(start - 1 + limit)]

    return obj

class UserFilter(Resource):
    def get(self):
        parser = reqparse.RequestParser()
        parser.add_argument('username', help='This field cannot be blank', required=True)
        data = parser.parse_args()
        current_users = UserModel.serialize_list(UserModel.query.filter(
            UserModel.username.like('%' + data['username'] + '%')).all())
        return jsonify(get_paginated_list_filter(
            current_users,
            'filter',
            start=request.args.get('start', 1),
            limit=request.args.get('limit', 20),
            query=data['username']
        ))

{
	"next": "filter?query=test&start=21&limit=10",
	"previous": "filter?query=test&start=1&limit=10",
	"results": [
		{
			"id": 25,
			"password": "$pbkdf2-sha256$29000$7b0XwnjvXct5T6m1NgbgnA$yhP3hg.IE76kLIQSHCtO4ghS6Wt2zbcpEygimkL1XK8",
			"username": "Testowy7"
		},
		{
			"id": 26,
			"password": "$pbkdf2-sha256$29000$xPh/D2FMaW0NQYgxRqjVOg$QG3Z1X8oWVgZ.M8A/yWY2fWo/HRB.NAN2xwWqv9fUMA",
			"username": "Testowy8"