以下方法，在ubuntu16.04亲测通过
wangpan@wangpan-OptiPlex-7050:~$ pip install opencv-python
Collecting opencv-python
Downloading https://files.pythonhosted.org/packages/e8/04/925d40d1aca43b949453c9350345ac0b4ca122d479d6d254a54ad0d1dd23/opencv_python-4.0.0.21-cp27-cp27mu-manylinux1_x86_64.whl (25.4MB)
100% |████████████████████████████████| 25.4MB 2.1MB/s
Requirement already satisfied: numpy>=1.11.1 in ./anaconda2/lib/python2.7/site-packages (from opencv-python) (1.15.4)
Installing collected packages: opencv-python
Successfully installed opencv-python-4.0.0.21