my from sklearn.decomposition import PCA have an error - python-2.7

Question

I tried using "from sklearn.decomposition import PCA" on windows python 2.7 to my program, but the result was an error and it said like this:
Traceback (most recent call last):
File "<pyshell#6>", line 1, in <module>
from sklearn.decomposition import PCA
File "C:\Python27\lib\site-packages\sklearn\decomposition\__init__.py", line 10, in <module>
from .kernel_pca import KernelPCA
File "C:\Python27\lib\site-packages\sklearn\decomposition\kernel_pca.py", line 14, in <module>
from ..preprocessing import KernelCenterer
File "C:\Python27\lib\site-packages\sklearn\preprocessing\__init__.py", line 8, in <module>
from .data import Binarizer
File "C:\Python27\lib\site-packages\sklearn\preprocessing\data.py", line 18, in <module>
from scipy import stats
File "C:\Python27\lib\site-packages\scipy\stats\__init__.py", line 343, in <module>
from .stats import *
File "C:\Python27\lib\site-packages\scipy\stats\stats.py", line 171, in <module>
from . import distributions
File "C:\Python27\lib\site-packages\scipy\stats\distributions.py", line 10, in <module>
from ._distn_infrastructure import (entropy, rv_discrete, rv_continuous,
File "C:\Python27\lib\site-packages\scipy\stats\_distn_infrastructure.py", line 16, in <module>
from scipy.misc import doccer
File "C:\Python27\lib\site-packages\scipy\misc\__init__.py", line 97, in <module>
from .pilutil import *
File "C:\Python27\lib\site-packages\scipy\misc\pilutil.py", line 21, in <module>
import Image
File "C:\Python27\lib\site-packages\PIL\Image.py", line 27, in <module>
from . import VERSION, PILLOW_VERSION, _plugins
ValueError: Attempted relative import in non-package
what's wrong with that? yesterday back then, I used that "from sklearn.decomposition import PCA" to my program and there's no problem whit that. help me please