Django Tutorial Review

http://www.flickr.com/photos/stevewall/1095860966/

Don't forget to commit

Commit early and often! Every time your code is working with a new feature or bugfix, you should commit it so that you have that snapshot available later if you need to come back to it. Use hg status frequently to make sure you haven't forgotten to add any files (or add them to your .hgignore). Don't leave files around showing a ? in hg status: if they should be added, hg add them; if they should be ignored, put them in .hgignore.

I'll often use Mercurial to clone a copy of your work that I can play with locally. As far as I'm concerned, if it isn't committed it doesn't exist.

Be hygienic

If you're using Mercurial properly you can delete stuff fearlessly, rather than leaving big ugly chunks of commented code laying around. If you need to go back to what you had before, it's there in your revision history.

BlogPost

class BlogPost(object):
  #...
  def as_html(self):
    " Return HTML-formatted blog post. "

    lines = [
      '<h3 class="post_title"><a href="#permalink">%s</a></h3>' % self.title,
      '<span class="post_author">%s</span>' % self.author,
      '<span class="post_date">%s</span>' % self.pub_date
    ]

    for paragraph in self.content.split('\n\n'):
      lines.append('<p>%s</p>' % paragraph)

    return '\n'.join(lines)

Notes

In general, use string-formatting (%s) and build up lists of lines to join; avoid string-concatenation with +.
Use semantic HTML. Your HTML should define only the meaning of things, not how they are displayed. For instance, this means the <br> tag should only be used in places where a linebreak is semantically meaningful; i.e. poetry, or a mailing address.
In reality, we'll almost never generate HTML in Python code like that. Mixing code and HTML makes things hard to maintain; use templates instead.

Classes and methods

Note that methods can be assigned and passed around just like regular functions. Even if you aren't passing arguments, you always use () to call a function or method:

>>> my_post = BlogPost(title='My Title', content='some content')
>>> f = my_post.as_html
>>> f
<bound method BlogPost.as_html of <blog.BlogPost object at 0x7f9414188310>>

>>> my_post.as_html
<bound method BlogPost.as_html of <blog.BlogPost object at 0x7f9414188310>>

>>> f()
'<h3 id="post_title">...'

>>> my_post.as_html()
'<h3 id="post_title">