每次运行，都提示这样的错误：
/usr/local/lib/python2.7/dist-packages/sklearn/utils/__init__.py:12: RuntimeWarning: numpy.dtype size changed, may indicate binary incompatibility. Expected 96, got 88
from .murmurhash import murmurhash3_32
/usr/local/lib/python2.7/dist-packages/sklearn/utils/extmath.py:23: RuntimeWarning: numpy.dtype size changed, may indicate binary incompatibility. Expected 96, got 88
from ._logistic_sigmoid import _log_logistic_sigmoid
/usr/local/lib/python2.7/dist-packages/sklearn/utils/extmath.py:25: RuntimeWarning: numpy.dtype size changed, may indicate binary incompatibility. Expected 96, got 88
from .sparsefuncs_fast import csr_row_norms
/usr/local/lib/python2.7/dist-packages/sklearn/metrics/cluster/supervised.py:25: RuntimeWarning: numpy.dtype size changed, may indicate binary incompatibility. Expected 96, got 88
from .expected_mutual_info_fast import expected_mutual_information
/usr/local/lib/python2.7/dist-packages/sklearn/metrics/pairwise.py:31: RuntimeWarning: numpy.dtype size changed, may indicate binary incompatibility. Expected 96, got 88
from .pairwise_fast import _chi2_kernel_fast, _sparse_manhattan
看得多了，觉得这是个问题．上网一查，说是python2.7使用的numpy版本太高（吾版本是1.15.0），要降级．解决办法是：
sudo pip uninstall numpy
sudo pip install -U numpy==1.14.5
