import matplotlib.pylab A big problem

I am a rookie in linux.
I input the following sentence in the python environment of OpenSuse 12.3
: import matplotlib.pylab
and the following is the error :
import matplotlib.pyplot
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/site-packages/matplotlib/__init__.py", line 123, in <module>
import os, re, shutil, warnings
File "/usr/lib/python2.7/shutil.py", line 12, in <module>
import collections
File "collections.py", line 13, in <module>
import numpy as np
File "/usr/lib/python2.7/site-packages/numpy/__init__.py", line 153, in <module>
from . import add_newdocs
File "/usr/lib/python2.7/site-packages/numpy/add_newdocs.py", line 13, in <module>
from numpy.lib import add_newdoc
File "/usr/lib/python2.7/site-packages/numpy/lib/__init__.py", line 6, in <module>
from .type_check import *
File "/usr/lib/python2.7/site-packages/numpy/lib/type_check.py", line 11, in <module>
import numpy.core.numeric as _nx
File "/usr/lib/python2.7/site-packages/numpy/core/__init__.py", line 46, in <module>
from numpy.testing import Tester
File "/usr/lib/python2.7/site-packages/numpy/testing/__init__.py", line 10, in <module>
from unittest import TestCase
File "/usr/lib/python2.7/unittest/__init__.py", line 58, in <module>
from .result import TestResult
File "/usr/lib/python2.7/unittest/result.py", line 9, in <module>
from . import util
File "/usr/lib/python2.7/unittest/util.py", line 2, in <module>
from collections import namedtuple, OrderedDict
ImportError: cannot import name namedtuple


I have update the python and install the numpy,scipy,matplotlib
So ,could u help me solve theproblem?I beg ur help,thanks:'(