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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 add_prefix(self, prefix):
 """ Prefix labels with string `prefix`. For Series, the row labels are prefixed. For DataFrame, the column labels are prefixed. Parameters prefix : str The string to add before each label. Returns ------- Series or DataFrame New Series or DataFrame with updated labels. See Also -------- Series.add_suffix: Suffix row labels with string `suffix`. DataFrame.add_suffix: Suffix column labels with string `suffix`. Examples -------- 0 1 1 2 2 3 3 4 dtype: int64 item_0 1 item_1 2 item_2 3 item_3 4 dtype: int64 A B 0 1 3 1 2 4 2 3 5 3 4 6 col_A col_B 0 1 3 1 2 4 2 3 5 3 4 6 """

        f = functools.partial('{prefix}{}'.format, prefix=prefix)

        mapper = {self._info_axis_name: f}
        return self.rename(**mapper)