from qgis.core import *
from qgis.gui import *
from PyQt4.QtGui import *
from PyQt4.QtCore import *
import os
#coding=system


def group_name():
  root = QgsProject.instance().layerTreeRoot()
  print root.name()


group_name()

for group in iface.legendInterface().groups():
    print group

groups = iface.legendInterface().groups()
groups[0]