def mapping_id(self): esb = EnsemblRelease(77) self.data_filtered['ensembl_id_1'] = [ esb.gene_id_of_protein_id(protein) for protein in self.data_filtered.protein1 ] self.data_filtered['ensembl_id_2'] = [ esb.gene_id_of_protein_id(protein) for protein in self.data_filtered.protein2 ]