def __init__(self, value, dimstr, utype=None):
        '''takes name of base unit and creates a Base object'''
        if utype=='BASE':   # manually create the dimension for a base unit
            self.value=value            # value of dimension
            self.dims={}    # dict of dimensions, keys are base units
            self.dims[dimstr]=1
        else:               # we're building a compound unit 
            if dimstr.strip()=='':  # no Dim object yet, so build it
                self.value=value
                self.dims={}
            else:
                tmp=ap_eval(dimstr,units)
                # At this point we have a Dim object
                self.value=value*tmp.value
                self.dims=tmp.dims
takes name of base unit and creates a Base object
recipes/Python/577333_Numerical_type_units/recipe-577333.py