ModuleNotFoundError: No module named 'schulze_helper'

[boompig]

After installing from pip, get this error when running code below:

from pyvotecore.schulze_method import SchulzeMethod
from pyvotecore.condorcet import CondorcetHelper
ballots = []
SchulzeMethod(ballots, ballot_notation = CondorcetHelper.BALLOT_NOTATION_GROUPING).as_dict()