Sure is a python library for python that leverages a DSL for writing assertions created by Gabriel Falcão.

In CPython it monkey-patches the object type, adding some methods and properties purely for test purposes.

Any python code writen after import sure gains testing superpowers, so you can write assertions like this:

import sure

def some_bratty_function(parameter):
    raise ValueError("Me no likey {0}".format(parameter))

some_bratty_function.when.called_with("Scooby").should.throw(ValueError, "Me no likey Scooby")

Let’s get it started