Ok, I finally found how to do it, for example to display all values :
for line in self.tree.get_children(): for value in self.tree.item(line)['values']: print(value)
use this code :
for Parent in self.treeview.get_children(): print(self.treeview.item(Parent)["text"]) for child in self.treeview.get_children(Parent): data = self.treeview.item(child)["text"] print(data)