def combine_first(self, other):
        new_index = self.index.union(other.index)
        this = self.reindex(new_index, copy=False)
        other = other.reindex(new_index, copy=False)
        # TODO: do we need name?
        name = _maybe_match_name(self, other)  # noqa
        rs_vals = com._where_compat(isnull(this), other._values, this._values)
        return self._constructor(rs_vals, index=new_index).__finalize__(self)
Add a right join to the query
dataset/ETHPy150Open pydata/pandas/pandas/core/series.py/Series.combine_first--crossover with--dataset/ETHPy150Open sdispater/orator/orator/query/builder.py/QueryBuilder.right_join