Read my previous two posts on Django and Python - Part I and Part II

I've been working on a project management tool suite in Django. It's been a great side project to really experiment with Django in real-world scenarios.

Forms

At times I feel like I fight with newforms. In particular, it lacks the ability to specify basic class or style attributes for a given form field from within the template. I'd like to be able to more finely tune the display of the field, directly within the template, with a style attribute or a class. Is it suggested you write your own custom form field widget for a single element? I've been getting around this by doing the following:

<input type="text" name="{{ todo_form.item.name }}" style="width: 720px;"/>

This gets more complicated if you want to set a style attribute for a form field that's a select box (for a ForeignKey model field, for example).

<label for="category">Category:</label> <select name="{{ category_form.project.name }}" style="width: 221px;">
{% for choice_val, choice_label in category_form.project.field.choices %}
	<option value="{{ choice_val }}">{{ choice_label }}</option>
{% endfor %}

Is this a good use case for template tags? I feel like I'm missing something here.

On the positive side, it was an absolute pleasure to work with multiple forms on a single page submitted to and processed by a single view. This is primarily thanks to prefixes. Excellent, that's how easy it should be.

Ternary Operator

Update: It's been pointed out in comments (thanks!) that Python 2.5 introduced a ternary operator. It's syntax is as follows:

label = "true" if booleanVariable else "false"

I also ran into a minor Python syntax issue. I love the ternary operator in languages that offer it. It's a concise, one-line, syntax for an if-else clause. Consider the following PHP code:

$label = $booleanVariable ? 'true' : 'false';

// the above is identical to the following block:
if($booleanVariable) {
   $label = 'true';
} else {
   $label = 'false';
}

Python unfortunately lacks this syntactic sugar. Fortunately, however, you can effectively accomplish the same thing by doing this:

label = (booleanVariable and 'true' or 'false')

# the above is equivalent to the following block:
if booleanVariable:
   label = 'true'
else:
   label = 'false'

Sessions

Django has built in support for sessions. By default, sessions last longer than the lifecycle of the user's browser. I personally think it should be the other way around. It's easily changed though (in your settings.py):

SESSION_EXPIRE_AT_BROWSER_CLOSE = False

Views

In one of my views I wanted to test whether a filtered result set was empty or not. I was curious whether this was the "pythonic" way to accomplish this:

account = get_object_or_404(Account, pk=account_id)
if account.useraccount_set.filter(user__exact=request.user) != []:

Also, with respect to views and passing context to the response, sometimes it's an efficient shortcut to use locals() instead of explicitly typing out all the variables you'd like to expose. locals() returns a dictionary of all variables defined within the local scope.

def myview(request, id):
    account = get_object_or_404(Account, pk=id)
    new_account_form = NewAccountForm()

    return render_to_response('myview.html', locals())

More soon!

Related posts:

1. Django URL Parameter Passing and Python Strings
2. Django and Python First Impressions – Part II
3. Getting Started with Django and Python – First Impressions
4. Setup Python 2.5, mod_wsgi, and Django 1.0 on CentOS 5 (cPanel)
5. Setup Python 2.6.4, mod_wsgi 2.6, and Django 1.1.1 on CentOS 5.3 (cPanel)