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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 uniquify_by(self, column, chooser=None, aggregate='MAX'):
 """ Group by `column` and run `aggregate` function on `chooser` column. """

        self.group_by.append(column)
        if chooser:
            i = self.columns.index(chooser)
            self.columns[i] = '{0}({1})'.format(aggregate, self.columns[i])