def_physical_type

astropy.units.def_physical_type(unit, name)

Add a mapping between a unit and the corresponding physical type(s).

If a physical type already exists for a unit, add new physical type names so long as those names are not already in use for other physical types.

Parameters:

unitUnit

The unit to be represented by the physical type.

namestr or set of str

A str representing the name of the physical type of the unit, or a set containing strings that represent one or more names of physical types.

Raises:

ValueError

If a physical type name is already in use for another unit, or if attempting to name a unit as "unknown".