If you want to use it inside a python script you have to import it. Let say you import it this way: from unify import unify
Unify is written for converting from one unit to another. Let say you have a string like this: length='15.0168*cm'
Now if you need this length to be given in mm you do: length=unify(length+'/mm')
and now your length is in mm, whatever the unit in which it was given in the first place.
Note that the output returned by unify is still a string, so if you need to do a calculation with length in the above example, you will need to call float(length) first!