def addMolecule(self, mol, name=None): if name is None: name = mol.name d = MoleculeDrawer(self._int, mol, name) self.c += 1 if self.c >= self.cols: self.c = 0 self.r += 1 self._int.grid_rowconfigure(self.r, weight=1) d.grid(row=self.r, column=self.c, sticky="NEWS")