In [1]: import pyunitwizard as puw

In [2]: puw.configure.load_libraries(['pint', 'openmm.unit'])
   ...: puw.configure.set_default_form('pint')
   ...: puw.configure.set_standard_units(['nm', 'ps', 'kcal', 'mole'])
   ...: 

In [3]: q = puw.quantity(2.5, 'nanometers/picoseconds')

In [4]: puw.get_form(q)
Out[4]: 'pint'

In [5]: puw.get_value(q)
Out[5]: 2.5

In [6]: puw.get_unit(q)
Out[6]: <Unit('nanometer / picosecond')>

In [7]: puw.dimensionality(q)
Out[7]: {'[L]': 1, '[M]': 0, '[T]': -1, '[K]': 0, '[mol]': 0, '[A]': 0, '[Cd]': 0}

In [8]: q2 = puw.convert(q, to_unit='angstroms/femtoseconds', to_form='openmm.unit')

In [9]: print(q2)
0.025000000000000005 A/fs

In [10]: puw.get_form(q2)
Out[10]: 'openmm.unit'

In [11]: puw.compatibility(q, q2)
Out[11]: True

In [12]: q3 = puw.standardize(q2)

In [13]: print('q3 is now a {} quantity expressed in {}.'.format(puw.get_form(q3), puw.get_unit(q3)))
q3 is now a pint quantity expressed in nanometer / picosecond.