app.route('/reviews/')
@app.route('/reviews/<int:page>')
def reviews(page = 1):
    title = "Llista de comentaris"
    per_page = 3
    previous = "window.location.href='/reviews/{}'".format(page -1)
    next = "window.location.href='/reviews/{}'".format(page + 1)
    comment_list = Comment.query.join(User).add_columns(
                            User.username, Comment.text).paginate(page, per_page, False)


return render_template('reviews.html', comment_list = comment_list, page = page, next = next, previous = previous)</pre><div>Código en reviews.html:</div><pre>    {% if comment_list.has_prev %}
&lt;button type="button" name="button" class="btn btn-primary" onclick={{previous}}&gt;&lt;&lt;/button&gt;
{% endif %}
&lt;button type="button" name="button" class="btn"&gt;{{page}}&lt;/button&gt;
{% if comment_list.has_next %}
&lt;button type="button" name="button" class="btn btn-primary" onclick={{next}}&gt;&gt;&lt;/button&gt;
{% endif %}</pre>

<div class="container">
    <h5> Pagina: {{comments.page}} </h5>
    <!-- anterior -->
    {% if comments.has_prev  %}
        <li><a href="{{ comments.page-1}}">Anterior</a></li>
    {% endif %}
    <!-- Siguiente -->
    {% if comments.has_next %}
        <li><a href="{{ comments.page+1}}">Siguiente</a></li>
    {% endif %}


</div>

<li><a href="{{ url_for('datos') }}/{{prev}}">Anterior</a></li>
en mi main.py
next_page = page+1
prev_page = page-1
return render_template('puntos.html', cursor=cursor, title=title, form=search_form, next=next_page, prev=prev_page)