def unit(key):
 _check_obsolete(key)
 return physical_constants[key][1]

def unit ( key ) : _check_obsolete ( key ) return physical_constants [ key ] [ 1 ]
unit in physical_constants indexed by key parameters key : python string or unicode key in dictionary physical_constants returns unit : python string unit in physical_constants corresponding to key see also codata : contains the description of physical_constants .