def areplace (a,oldval,newval):
        return N.where(a==oldval,newval,a)
https://developer.riotgames.com/api/methods#!/1034/3540
dataset/ETHPy150Open sunlightlabs/clearspending/completeness/statlib/pstat.py/areplace--crossover with--dataset/ETHPy150Open meraki-analytics/cassiopeia/cassiopeia/dto/championmasteryapi.py/get_top_champion_masteries