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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 readCell(self, row, col):
        ''' read a cell'''
        try:
            if self.__sheet is None:
                self.openSheet(super(ExcelRead, self).DEFAULT_SHEET)

            return self.__sheet.cell(row, col).value
        except BaseException as excp:
            raise UfException(Errors.UNKNOWN_ERROR, "Unknown Error in Excellib.readCell %s" % excp)