def stem(word):
    return word.lower().rstrip(",.!:;'-\"").lstrip("'\"")
No direction in order shoud raise MissingParameter
dataset/ETHPy150Open pytoolz/toolz/bench/test_wordcount.py/stem--crossover with--dataset/ETHPy150Open jcbagneris/fms/tests/markets.py/MarketTests.test_sanitize_order_direction