def compute_positivity(dico):
    "  This computes the positivity score of each statement. \n    Takes a dictionary with each statement as liste item and the corresponding interlocutor's name in names item  \n    \n    "
    dico_score = defaultdict((lambda : list()))
    for (name, liste) in dico.items():
        neg_score = 0
        pos_score = 0
        for ele in liste:
            if (ele in negative_word_list):
                neg_score += 1
            elif (ele in positive_word_list):
                pos_score += 1
            else:
                pass
        if ((neg_score < 30) or (pos_score < 30)):
            pass
        else:
            score = ((pos_score - neg_score) / (pos_score + neg_score))
            dico_score[name] = score
    return dico_score
This computes the positivity score of each statement. 
Takes a dictionary with each statement as liste item and the corresponding interlocutor's name in names item
def compute_positivity(dico):
    "  This computes the positivity score of each statement. \n    Takes a dictionary with each statement as liste item and the corresponding interlocutor's name in names item  \n    \n    "
    dico_score = defaultdict((lambda : list()))
    for (name, liste) in dico.items():
        neg_score = 0
        pos_score = 0
        for ele in liste:
            if (ele in negative_word_list):
                neg_score += 1
            elif (ele in positive_word_list):
                pos_score += 1
            else:
                pass
        if ((neg_score < 30) or (pos_score < 30)):
            pass
        else:
            score = ((pos_score - neg_score) / (pos_score + neg_score))
            dico_score[name] = score
    return dico_score