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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 sentiment( text = None, confidence = False ):
 """ This function accepts a string text input. It calculates the sentiment of the text, "pos" or "neg". By default, it returns this calculated sentiment. If selected, it returns a tuple of the calculated sentiment and the classificaton confidence. """

    try:
        words = text.split(" ")
        # Remove empty strings.
        words = [word for word in words if word]
        features = word_features(words)
        classification = classifier.classify(features)
        confidence_classification = classifier.prob_classify(features).prob(classification)
    except:
        classification = None
        confidence_classification = None
    if confidence:
        return (
            classification,
            confidence_classification
        )
    else:
        return classification