astrofrog/astropy — pull request #22 by iguananaut (2012-12-18 23:03:33+00:00)
Title: Constants refactor 2

Here's an update to astropy/astropy#572 illustrating something like what I have in mind. It still has the shortcoming that doing something like

```
from astropy.constants import e
from astropy.units import Quantity as Q

e * Q(100, 'V')
```

Will treat `e` as being in Coulombs. I think though that with a few more tweaks to the `EMConstant` class we could prevent this implicit behavior if desired.