如何在Jinja2模板中获取列表中的列表

Question

In Flask,

@app.route('/test')
def test():
    test = ['a','b','c','d','e','f','g',['1','2','3']]
    return render_template('test.html',data=test)

here is my template :

{% for item in data %}
<tr>
  <td>{{item.0}}</td> 
  <td>{{item.1}}</td>  
  <td>{{item.2}}</td>
  <td>{{item.3}}</td> 
  <td>{{item.4}}</td>  
  <td>{{item.5}}</td>
  <td>{{item.6}}</td>
</tr>
<tr>
  <td colspan="5">{{ item[7][0]}}</td>
  <td>{{ item[7][1]}}</td>
  <td>{{ item[7][2]}}</td>
</tr>
{% endfor %}

But always getting error:

jinja2.exceptions.UndefinedError: str object has no element 7

How to get the list in list?

Looks like jinja2 need string, but it can't regonize python item[7][0] format. I also tried item.7.0 and item.7[0] , but same error.

Thanks!

Answer 1

You're passing in to the template a list consisting of 8 elements (7 strings and another list of strings).

Then in your Jinja template you're iterating over that list:

{% for item in data %}

However, in your loop you're trying to access each list member individually, but this doesn't make sense inside the context of the loop.

Your code as it stands would work without the for loop:

<tr>                                                                            
  <td>{{data.0}}</td>                                                           
  <td>{{data.1}}</td>                                                           
  <td>{{data.2}}</td>                                                           
  <td>{{data.3}}</td>                                                           
  <td>{{data.4}}</td>                                                           
  <td>{{data.5}}</td>                                                           
  <td>{{data.6}}</td>                                                           
</tr>                                                                           
<tr>                                                                            
  <td colspan="5">{{ data[7][0]}}</td>                                          
  <td>{{ data[7][1]}}</td>                                                      
  <td>{{ data[7][2]}}</td>                                                      
</tr> 

output:

<tr>
  <td>a</td> 
  <td>b</td>  
  <td>c</td>
  <td>d</td> 
  <td>e</td>  
  <td>f</td>
  <td>g</td>
</tr>
<tr>
  <td colspan="5">1</td>
  <td>2</td>
  <td>3</td>
</tr>

Answer 2

Try

{% for item in data %}
    <tr>
    {% if item|string %}  #or {% if item is string %}
        <td>{{item}}</td> 
    {% else %}
        {% for item_iside in item %}
            <td>{{item_iside}}</td> 
    {% endif %}
    </tr>
{% endfor %}

Answer 3

Thanks!

I just didn't provide a good test data After Matt answer reminding me, I found I made a stupid mistake. after chnage test to:

test =[ ['a1','b1','c1','d1','e1','f1','g1',['1','2','3']],
        ['a2','b2','c2','d2','e2','f2','g2',['2','3','4']]
        ]

the loop works now

Thank you guys.