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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def load_mldataset(filename):
 """Not particularly fast code to parse the text file and load it into three NDArray's and product an NDArrayIter """

    user = []
    item = []
    score = []
    with open(filename) as f:
        for line in f:
            tks = line.strip().split('\t')
            if len(tks) != 4:
                continue
            user.append(int(tks[0]))
            item.append(int(tks[1]))
            score.append(float(tks[2]))
    user = mx.nd.array(user)
    item = mx.nd.array(item)
    score = mx.nd.array(score)
    return gluon.data.ArrayDataset(user, item, score)