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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 topports(sort_by='records', limit=10, date=None, return_format=None):
 """Information about top ports for a particular date with return limit. :param sort_by: one of 'records', 'targets', 'sources' :param limit: number of records to be returned :param date: an optional string in 'Y-M-D' format or datetime.date() object """

    uri = '/'.join(['topports', sort_by, str(limit)])
    if date:
        try:
            uri = '/'.join([uri, date.strftime("%Y-%m-%d")])
        except AttributeError:
            uri = '/'.join([uri, date])
    return _get(uri, return_format)