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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 pluralize(data_type):
 """ adds s to the data type or the correct english plural form """

    known = {
             u"address": u"addresses", 
             u"company": u"companies"
    }
    if data_type in known.keys():
        return known[data_type]
    else:
        return u"%ss" % data_type