Posts

Many developers see the value in getting started with testing their web applications, but don’t know how to actually start using it. I’ll write about a variety of products and processes which cover the whole range of testing web applications. The posts in this series will be published in the coming weeks. You can find a rough table of contents below but the list may get modified or extended. Approach Initially you must spend some thoughts on how you want to approach testing. The main obstacle is that almost always you start with an existing project that already has a big code base. It seems impossible to ever get enough testing in place to be meaningful. But my experience shows that even very little coverage can already improve quality of your system a lot. ...

The Semantic Web is one of those technologies I’ve heard so often that I got tired of it. But lately I’ve become more interested in one aspect of the whole Semantic Web: graph data. Graph databases are basically one of the many different ways to store data - something which is currently being hyped under the awful name “NoSQL”. So much so that Neo4J, one of the well-known graph databases, even uses that term in their title now. ...

It’s no secret that around here we are big wiki fans. But the paradox of wikis is that it’s so easy to collect information that suddenly there is too much of it. And that makes it hard to navigate the information. So a wiki must constantly be refactored - especially the navigation structures. But no matter how good your navigation structures are, how do you make it easy for newcomers to get into the wiki? Our main space at Nektoon contains 452 pages at the moment - that’s after only six months of existence. At local.ch, my former work, there is a lot more after several years of wiki usage with many more people involved. ...

For returning complex values from a method you have a few popular choices: Return a tuple with positional values. Those are very easy to unpack in Python and quite attractive because of that. Return a dictionary with the values. This can lead to slightly verbose accessing of the individual values. Return an object of some class you define. This required the definition of a class which can be too verbose for just a simple return value. Since Python 2.6 you have one additional tool: collections.namedtuple. They give you a very lightweight class but it’s a one-liner to define them. ...

I did a presentation at the March swiss.py user group meeting about using Python eggs. I hear a lot of bitching about Python’s packaging. Guido even managed to talk at lengths about the problems with it at his PyCon keynote talk. Here I am boldly saying almost the opposite: Python packaging rocks! It’s very easy to have a great workflow both for development as well as deployment using Python eggs. Some notes from the presentation which you can download as a PDF. ...

The Safari web browser can autofill form fields from your personal address book card. I’ve had very good experiences with this feature. But today I was creeped out a little on my brightkite profile as I saw my birthday even though I had not provided it anywhere. It took me a moment to realize that Safari had autofilled my birthday. So I quickly came up with an evil idea. Would it be possible to abuse that feature to automatically collect birthdays from users on say a signup form? ...

nose is my Python testing tool of choice. You can use it to very easily create test suites. While it does support the unittest module which is included with Python, it also allows for a much simple style using just methods and asserts. Put the following code into a file called test_basic.py: <notextile>def test_addition(): print 2 + 2 assert 2 + 2 == 4 def test_addition_wrong(): print 2 + 3 assert 2 + 3 == 6</notextile> Then just run nosetests in the directory where you stored this file. You’ll get an output indicating, that there is a test failure. ...

Tomorrow (March 31) we’ll hold the second swiss.py user group event. We’ll meet at the main ETH building at 19:30. If all goes well, Florian Bösch will talk about OpenGL development using Python. He’s currently not feeling that well, so the topic might change on the day itself. Get more details on the official swiss.py web site.

The local.ch location pages contain many nice information about every city and village from Switzerland. Since putting the regional news online, I regularly look at the location page for Olten. I’ve now created a Greasmonkey script which - once installed - automatically jumps from tab to tab every five seconds. You can get the script. When you open that page Greasemonkey will ask you to install the script. I’ve tested the script both with the original Greasemonkey as well as with the Safari implementation GreaseKit.

Python’s with statement can be a very elegant alternative to long try/except/finally clauses. It offers a standard protocol that classes can implement to properly clean up state. The best example for it’s value is file reading. A good implementation would have to look like this traditionally: f = open('/tmp/myfile', 'r') try: content = f.read() finally: f.close() The with statement shortens this to the following code: with open('/tmp/myfile', 'r') as f: content = f.read() Behind the scenes it wraps the finally statement around this and makes sure that the file gets closed upon leaving the with block. ...