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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 nametoindex(self, sds_name):
 """Return the index number of a dataset given the dataset name. Args:: sds_name : dataset name Returns:: index number of the dataset C library equivalent : SDnametoindex """


        sds_idx = _C.SDnametoindex(self._id, sds_name)
        _checkErr('nametoindex', sds_idx, 'non existent SDS')
        return sds_idx