cmake cannot find python2_libraries

[tymiao1220]

System Mac 10.12 Sierra
Cmake 3.7

I am following http://www.pyimagesearch.com/2016/11/28/macos-install-opencv-3-and-python-2-7/, to install python2.7 with opencv, but I come across a issue which Is when I tried to configure them via cmake, it shows like:
-- Python 2:
-- Interpreter: /Users/tianyimiao/.virtualenvs/cv/bin/python (ver 2.7.10)
-- Libraries: NO
-- numpy: /Users/tianyimiao/.virtualenvs/cv/lib/python2.7/site-packages/numpy/core/include (ver 1.11.2)
-- packages path: lib/python2.7/site-packages

The Cmake Library path I use is:
cmake -D CMAKE_BUILD_TYPE=RELEASE
-D CMAKE_INSTALL_PREFIX=/usr/local
-D OPENCV_EXTRA_MODULES_PATH=~/opencv_contrib/modules
-D PYTHON2_LIBRARY=/usr/local/Cellar/python/2.7.12_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/config/libpython2.7.dylib
-D PYTHON2_INCLUDE_DIR=/usr/local/Cellar/python/2.7.12_2/Frameworks/Python.framework/Versions/2.7/include/python2.7
-D PYTHON2_EXECUTABLE=$VIRTUAL_ENV/bin/python
-D BUILD_opencv_python2=ON
-D BUILD_opencv_python3=OFF
-D INSTALL_PYTHON_EXAMPLES=ON
-D INSTALL_C_EXAMPLES=OFF
-D BUILD_EXAMPLES=ON ..

The libraries cannot be found all the time, and I have tried to delete and recreate build several times and it does not work, and the specified Library path I used is right coz I can find that 'libpython2.7.dylib' file by that path.

I am new at Mac and python as well, so really want to know the reason and how to fix that.
I appreciate for any help! Thank you