add text descriptions for Ppi and PpiComplex models

ippisite/ippidb/models.py

@@ -153,6 +153,9 @@ class Ppi(models.Model):
     pdb_id = models.CharField('PDB ID', max_length=4, null=True)
     symmetry = models.ForeignKey(Symmetry)
 
+    def __str__(self):
+        return '{} PPI, PDB:{}'.format(self.symmetry.description, self.pdb_id or 'unknown')
+
 class PpiComplex(models.Model):
     ppi = models.ForeignKey(Ppi)
     complex = models.ForeignKey(ProteinDomainComplex)
@@ -161,6 +164,9 @@ class PpiComplex(models.Model):
     class Meta:
         verbose_name_plural = "Ppi complexes"
 
+    def __str__(self):
+        return 'PPI {}, Complex {} ({})'.format(self.ppi, self.complex, self.cc_nb)
+
 class Disease(models.Model):
     ppi = models.ForeignKey(Ppi)
     disease_name = models.CharField('Disease', max_length=30) # is there any database/nomenclature for diseases?