def __init__(self, variables, p):
        self.variables = variables
        self.p = p
Subclasses may override this provide a pretty ID which can be used
dataset/ETHPy150Open lisa-lab/pylearn2/pylearn2/costs/cost.py/LpPenalty.__init__--crossover with--dataset/ETHPy150Open kwminnick/rackspace-dns-cli/dnsclient/base.py/Resource.human_id