pip安装tensorflow报错：could not find a version that satisfies the requirement grpcio>=1.8.6

下图红色字体为错误提示：

- ERROR: Could not find a version that satisfies the requirement grpcio>=1.8.6 (from tensorflow) (from versions: none)
- ERROR: No matching distribution found for grpcio>=1.8.6 (from tensorflow)

出错原因：没有安装numpy或者版本不够新。

解决办法：用 “pip install --upgrade numpy” 安装或者更新，然后再重新安装tensorflow 即可。

注意 pugrade 前边是两个连字符 “-” 哦

参考博文