解决 macOS LightGBM OSError报错 Library not loaded

在OSX上使用lightGBM报错

Traceback (most recent call last):

File “lgb.py”, line 12, in

import lightgbm as lgb

File “/python2.7/site-packages/lightgbm/init.py”,line 8, in

from .basic import Booster, Dataset

File “/python2.7/site-packages/lightgbm/basic.py”, line 32, in

_LIB = _load_lib()

File “/python2.7/site-packages/lightgbm/basic.py”, line 27, in _load_lib

lib = ctypes.cdll.LoadLibrary(lib_path[0])

File “/python/2.7.14/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/init.py”, line 444, in LoadLibrary

return self._dlltype(name)

File “/python/2.7.14/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/init.py”, line 366, in init

self._handle = _dlopen(self._name, mode)

OSError: dlopen(/lib/python2.7/site-packages/lightgbm/lib_lightgbm.so, 6): Library not loaded: /usr/local/opt/gcc/lib/gcc/7/libgomp.1.dylib

Referenced from: /lib/python2.7/site-packages/lightgbm/lib_lightgbm.so

Reason: image not found

原因：LightGBM编译依赖OpenMP，Apple Clang不支持

解决方法：

brew install cmake
brew install gcc

git clone --recursive https://github.com/Microsoft/LightGBM ; cd LightGBM
export CXX=g++-7 CC=gcc-7
mkdir build ; cd build
cmake ..
make -j4

pip install lightGBM

即可正常使用