Lettuce is a BDD tool written in python, 100% based on cucumber.

There are two reasons for the name:

• Lettuce is a green vegetable, just like cucumber the idea is that your tests must be always green.
• Letuce is the name of a brazillian band that I pretty much like

Hands on!

There are links to lettuce’s official documentation at the end of this post, but there is a sneak peak:

Features are described in files with .feature extension and must be, by defaul within your project, in a folder called “features“.

Features are described like this:

In order to define steps all you need to do is write a new python file wihin features folder, Lettuce will import them all, recursively.

Example:

(the full example is available here aqui)

Motivation

Since I started with TDD in Python I had many experiences, I’ve tested many mock mock libraries and test techniques.
In web projects I’ve used Pyccuracy, so that I could both describe behaviour of the application and make automated acceptance tests.

Althrough, I had a chance to try Cucumber with Django here at globo.com, and the result was: I fell in love with it, and had incredibly productive features, such as step tables which allows drawing a ascii table and map it into a list of hashes, and the scenario outlines.

From there I had THE inspiration: to implement a tool that works exactly like Cucumber, but in python.

Why ?

Python programmers it’s easier and frictionless to use libraries written in Python. I personally avoid mixing programming languages in a single project, some technologies can suit perfectly in the project, no matter in what language, but if there is a Python option, I will give it a go.

Cucumber IMHO one lib to make ruby even more “sexy”
Build a robust application, well tested required patience, what about turn it into fun ! ?
It’s easier to package python modules for debian/ubuntu.

Besides, even considering the fact that  Cucumber already supports, would be more interesting to user pure python within step definitions.
Supposing that a web application will be written with Django and Cucumber, would be very useful to manipulate models within step definitions. However turning it possible, would need efforts to run rubypython, which the latest release dates october 2009.

Examples of similar libraries between python and ruby

Web framework:

ruby: rails
python: django

Micro web framework:

ruby: sinatra
python: cherrypy

Automated deploy:

ruby: capistrano
python: fabric

Behaviour-driven development:

ruby: cucumber
python: lettuce ?! (maybe ?! Who knows ?!  )

More on lettuce

Documentation

Available at http://lettuce.it covers all supported features until now.

Contribute!

I’ll appreciate all kinds of feedback, to do so we have some channels:

• GitHub repository
• Junte-se à lettuce users mailing list
• bugtracker !

Lettuce is under GNU GPL 3+ and have a long way until get robust, and any kind of help is welcome: patches, documentation, language support and so on!

Grab it, and happy hacking

I mean, no matter if you do TDD or not, if you do care about continuous integration, this is all a real lose of time.

When thinking about shipping good software, the best combination is, indeed, quite simple:

1. Use a powerful IDE. You as developer don’t even need to now how the things work, let the IDE do everything for you. Eclipse is the one you really need.
2. Use a well known, certified and reliable language. Why using dynamic languages ? You don’t need to be agile, you need to ship something with trust value, so build it with java.
3. Don’t code, use wizards and boilerplate generators. Once again, what is better, easy money or thousands of hours hacking things from scratch ? You can use UML-based code generators, and super-duper eclipse plugins to generate your code. Forget all stress and make your project manager happy.
4. Prepare yourself for possible future needs. To build a real scallable application you must ALWAYS use a complex SOA approach, so you can separate business-rules in each module and distribute in many servers. A RESTful approach is even better. Forget everything about agile software development, your customer doesn’t need a term, he needs a full-featured project.

To but it bluntly, Fred Brooks was totally wrong in his book “The Mythical Man-Month”, about “no silver bullet”, the steps below are, indeed, a silver bullet and you can see proofs of this sentence in the “Martin Flawler’s” article.

Once I am a Django web developer, one of my first actions were to create a django deployment setup, good and flexible enough. The time passed on and have been got new experiences, and the best desision, i think, was to create a new python sandbox, i mean, a customized python environment.

How is it possible ?

Simple! Just compiling python from scratch, with a fake root path (a prefix)

Anyway, the deployment process involves more variables, like setting both htaccess and dispatch files for each project, installing some basic modules such PIL and MySQL and so on…

So, i ever wanted to create a super duper script to do all that “dirty” work. And i did it last weekend!

I were working ia a freelance job and decided to create a subdomain to host test instance of them.

A new sandbox, ready to make my tests to create the super script.

So folks, i present you the brand new: django_dreamhost.sh

It’s composed by 4 files:

• django_dreamhost.sh itself
• djangify.template – a template with will become a script to setup new projects (htaccess and dipatch files, for instance)
• htaccess.template – a template that will become the .htaccess of each project of yours
• dispatch.template – will become the dispatch.fcgi for your projects as well

“But do i need to download all them ?”, of course NO!

You just download the main script, and he will do all do hard work!

“I wanna contribute, modify or do anything with that script, can I ?”, of course yes! All parts of the script are GPLv2 +

You can also always get the development version through git repository:

git clone http://git.nacaolivre.org/django_dreamhost

Don’t want to get all code, just the script ?

Download it at: http://gnu.gabrielfalcao.com/django_dreamhost/django_dreamhost.sh

What does that script do ?

He will do the following steps:

1. Download Python, Django, Python-setuptools, Python-fastcgi to a directory called downloads
2. Extract all
3. Create a local root at $HOME/.myroot and the subdirs etc and usr
4. Set the new bin path to you global path through bashrc and bash_profile
5. Compile and install python to the new prefix: $HOME/.myroot/usr
6. Install Django, rename django-admin.py to django-admin
7. Setup your bash-completion to support django scripts
8. Install the python modules above with the new python
9. Install PIL and MYSQL modules through easy_install (setuptools)
10. Download the template scripts to $HOME/projects/script_templates
11. Replace the custom tags in templates
12. Move the djangify.template to the new bin PATH: $HOME/usr/bin and give it execution permission

I thinks it’s all.

I currently use Fabric to help on deployment, and i have a quite smart basic setup for it to work with this dreamhost django environment, but it will be approached in the next blog post

See you, folks!