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Thoughts about RSpec for Python
# codec: blocks
describe('articles.views.ArticleView'):
context('when user has permissions'):
it('should add new article'):
# some code
it('should delete existing article'):
# some code
context('when user has no permissions'):
it('should not add new article')
it('should not even show article form')
from bdd import describe, context, it
with describe('articles.views.ArticleView'):
with context('when user has permissions'):
@it('should add new article')
def test():
# some code
@it('should delete existing article')
def test():
# some code
with context('when user has no permissions'):
# pending tests
it('should not add new article')
it('should not even show article form')
@kesor
kesor commented May 9, 2012

How about creating a DSL with its own parser that generates and runs python code. Most python syntax highlight and auto-completion tools can work fine with it (bonus).

For example:

import spec_helper

describe articles.views.ArticleView
    context 'a user with permissions':
        it 'should add a new article':
            # some code
        it 'should delete an existing article':
            # some code
    context 'a user without permissions':
        it 'should not add a new article'
        it 'should not show the article form'

Then RSpec matchers can usually be translated into unittest2 assertions.
http://rubydoc.info/gems/rspec-expectations/RSpec/Matchers

Python unittest2 assertions are not really much more verbose than the .should and .should_not rspec helpers, but more pythonic:

assert expected is False
assert expected is None
assert expected is not None
assert isinstance(expected, list)
assert almost_equal(expected, 55)

As I don't like all those parenthesis (), signs like @, keywords like with and def in the original gist. And RSpec just can't be written as native Python, so no reason to force it - there are other ways.

@lostmarinero

What do you all think 2 years later, any suggestions? Still using sure? I am coming from Rspec and Jasmine and not saying I need everything the same, but I like being able to use contexts

@thefonso

I too would be interested in lostmarinero's question.

@rocknrollMarc

Im just starting python and come form ruby so rspec Ill let you know what I think and end up using but i like sure

@jdrago999

sheesh people. Years later and nothing?

Check out mamba https://github.com/nestorsalceda/mamba

We ended up not using it, but now I wish we had.

@eliasdorneles

@gabrielfalcao sure surely looks like a nice assertion library, thanks for that! :)

However, the discussion here is about a library that helps to structure tests, like RSpec does.
Namely, something that helps you to write test names and their structure, even before you actually write any assertion.
This is a powerful communication and designing tool, that gives you a lot more than simply a cool way to do assertions: it helps you to think, to plan and to adapt later on.
Assertions are probably not that important when it comes to high-level design, except when deciding to use mocks vs stubs.

This excerpt from the RSpec book might be a good introduction to these ideas: http://media.pragprog.com/titles/achbd/outside-in.pdf

I haven't find a really good tool in Python ecossystem for that yet.

mamba looks promising.
There are some other alternatives behave, pytest-bdd, lettuce and etc, but none seems to attempt to help the upfront thinking when design -- they always get in the way, requiring you to write boilerplate stuff.

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