使用Jinja2模板从数据库进行循环

Question

Goal: {% for loop %} over a list (using Jinja2 ) and then print out results {{print}} in a HTML table using Bootstrap.
Problem: List is not printing in the template.

In the view_config , I used query .all() to return a list of all the assessment_results objects. They are returning... I confirmed this via terminal/print debugging. However, the for loop is not returning the values needed to populate a table; as read in Jinja2 tutorial . I don't think I need to use a for loop in the view_config as I have seen others do ( see here ), but I am new to this and am trying to figure out how these two programs ( SQLALCHEMY and Jinja2 ) interact.

An example from the printout after using .all() mentioned above:

[<Assessment_Result(owner='<User(username ='baseball', firstname ='Jen', lastname ='See', email='girl@aol.com')>', assessment='<Assessment(name='Becoming a Leader', text='better decisions')>')>]

view_config code:
views.py

@view_config(route_name='assessment_results', request_method='GET', renderer='templates/assessment_results.jinja2')
def all_assessment_results(request):
    with transaction.manager: # < --- THIS WAS THE ISSUE ! 
        assessment_results = api.retrieve_assessment_results()
        if not assessment_results:
            raise HTTPNotFound()
        return {'assessment_results': assessment_results}

Corresponding Jinja2 template using Bootstrap:
assessment_results.jinja2

<div class="container">
    <table class="table table-hover">
        <thead>
            <tr>
                <td> Assessment ID </td>
                <td> Assessment </td>
                <td> Owner </td>
            </tr>
        </thead>
        <tbody>
            <tr>
                {% for x in assessment_results %}
                <td>{{ x.assessments|e }}</td>
                <td>{{ x.owners|e}}</td>
                {% else %}
                <td><em>no users found</em></td>
                {% endfor %}
            </tr>
        </tbody>
        </table>
    </div>

Answer 1

You should look at the documentation

http://jinja.pocoo.org/docs/dev/templates/#for

You want to iterate over a dict , so consider using iteritems , itervalues or what ever you want.

Also note that your query will not return a dict , it will return a list or rows that matched.

I am also not sure if the for-else works in jinja. But you should avoid using that anyways.