Question

I’m new to Python, and I’m using Google App Engine to build a simple blog to help me learn it. I have the following test code:

entries = db.Query(Entry).order("-published").get()
        comments = db.Query(Comment).order("published").get()
        self.response.out.write(template.render(templatePath + 'test.django.html', { 'entries': entries, 'comments': comments, }))

And a Django template that looks like this:

{% extends "master.django.html" %}

{% block pagetitle %}Test Page{% endblock pagetitle %}

{% block content %}

{% for e in entries %}

<p><a href="/post/{{ e.slug }}/">{{ e.title|escape }} - {{ e.published|date:"jS o\f F Y" }}</p>

{% endfor %}

{% for c in comments.all %}

<p>{{ c.authorname }} {{ c.published|date:"d/m/Y h:i" }}</p>

{% endfor %}

{% endblock content %}

When I view this templated page in the browser, I get:

TypeError: 'Entry' object is not iterable

Changing the line {% for e in entries %} to {% for e in entries.all %} solves this problem, which is great.

However, this is the bit I don’t understand; in another template (for the archive page), I pass in the same thing, a list of Entry objects:

entries = db.Query(Entry).order("-published").fetch(limit=100)
        self.response.out.write(template.render(templatePath + 'archive.django.html', { 'entries': entries, }))

With the template as follows:

{% extends "master.django.html" %}

{% block pagetitle %}Home Page{% endblock pagetitle %}

{% block content %}

<ul>

{% for entry in entries %}

<li><a href="/post/{{ entry.slug }}/">{{ entry.title|escape }} <span>{{ entry.published|date:"jS o\f F Y" }}</a>{% if admin %} - <a href="/compose/?key={{ entry.key }}">Edit Post</a>{% endif %}</span></li>

{% endfor %}

{% endblock content %}

This code works fine, without changing entries to entries.all; indeed if I do change it to that I get no output (no errors, just nothing at all).

Can someone explain why this is please?

Edit: I originally pasted the wrong piece of query code for the second example, which would probably have made things easier for people to give me an answer… changed it now.

Answer 1

You want to use .fetch(), not get():

entries = db.Query(Entry).order("-published").fetch()
comments = db.Query(Comment).order("published").fetch()

get() returns only the first item that matches the query criteria, so instead of an iterable collection, you’ll get one instance, and Entry object.

I can not explain why the second version does work. It really looks like it shouldn’t.