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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 get_Y_categories(self, entries=None):
 """ Returns names of y cat. of the IOSystem as unique names in order Parameters entries : List, optional If given, retuns an list with None for all values not in entries. Returns ------- Index List of categories, None if no attribute to determine list is available """

        possible_dataframes = ['Y', 'FY']

        for df in possible_dataframes:
            if (df in self.__dict__) and (getattr(self, df) is not None):
                try:
                    ind = getattr(self, df).columns.get_level_values(
                        'category').unique()
                except (AssertionError, KeyError):
                    ind = getattr(self, df).columns.get_level_values(
                        1).unique()
                if entries:
                    if type(entries) is str:
                        entries = [entries]
                    ind = ind.tolist()
                    return [None if ee not in entries else ee for ee in ind]
                else:
                    return ind
        else:
            logging.warn("No attributes available to get Y categories")
            return None