Error when import grpc: "Symbol not found: _deflate"解決方法

Import grpc時出現如下錯誤：

Traceback (most recent call last):
  File "/private/var/tmp/_bazel_lls/5ea0bb16383fa9c06c47b535a23ac475/execroot/ttsbot/bazel-out/darwin-opt/bin/client/tts_client.runfiles/ttsbot/client/tts_client.py", line 7, in <module>
    import grpc
  File "/anaconda3/lib/python3.6/site-packages/grpc/__init__.py", line 22, in <module>
    from grpc._cython import cygrpc as _cygrpc
ImportError: dlopen(/anaconda3/lib/python3.6/site-packages/grpc/_cython/cygrpc.cpython-36m-darwin.so, 2): Symbol not found: _deflate
  Referenced from: /anaconda3/lib/python3.6/site-packages/grpc/_cython/cygrpc.cpython-36m-darwin.so
  Expected in: flat namespace
 in /anaconda3/lib/python3.6/site-packages/grpc/_cython/cygrpc.cpython-36m-darwin.so
           

最終解決方法為在anaconda中安裝grpcio，指令為：

$ conda install grpcio