expecter 0.1

Better expectation library

BASICS

Expecter Gadget helps you to write assertions. Never again will you forget which is expected and which is actual!

Basic expectations are easy:

>>> from expecter import expect
>>> expect('some' + 'thing') == 'something'
>>> expect(1) > 100
Traceback (most recent call last):
...
AssertionError: Expected something greater than 100 but got 1

Just read the expectations like a sentence. “expect(2) == 1 + 1” reads as “Expect 2 to equal 1 + 1”. Obviously, the expectation is about 2, and it’s being compared to 1 + 1. No ambiguity!

EXCEPTIONS

Expectations about exceptions use the “with” statement. Everything is good if the expected exception is raised:

>>> from __future__ import with_statement
>>> with expect.raises(KeyError):
...     {}[123]

If it’s not raised, Expecter Gadget will raise an AssertionError:

>>> with expect.raises(KeyError):
...     pass
Traceback (most recent call last):
...
AssertionError: Expected an exception of type KeyError but got none

Exceptions that don’t match the expected one will not be swallowed, so your test will error as you expect:

>>> from __future__ import with_statement
>>> with expect.raises(NameError):
...     {}[123]
Traceback (most recent call last):
...
KeyError: 123