I'm writing tests for a small library and I decided to use py.test after hearing so many good things about it.

However, `pytest.mark.parameterize` is giving me some issues. At first, I thought maybe I just mismatched some parens and it went off looking for a fixture elsewhere. So I decided to start with the given example of parameterize:

```
@pytest.mark.parametrize("input,expected", [
    ("3+5", 8),
    ("2+4", 6),
    ("6*9", 42),
])
def test_eval(input, expected):
    assert eval(input) == expected

```

But this gives the same error:

> 
> fixture 'input' not found
> 
> 
> available fixtures: capfd, pytestconfig, recwarn, capsys, tmpdir, monkeypatch
> 
> 
> use 'py.test --fixtures [testpath]' for help on them.
> 
> 
> 

I went off googling, but I couldn't find any answers that applied. Any ideas on how to approach this?

Edit: I suppose knowing which Python/py.test versions is helpful.

Python 3.4.0 and py.test 2.6.4