Mac 安装tensorflow

python 环境。在Mac 系统上实行 pip install tensorflow 可能会出现下面的错误提示

Cannot uninstall 'numpy'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall.

是尝试卸载numpy时出现的错误，可用下面一行强行(忽略旧版本升级)安装新的numpy

sudo pip install --ignore-installed numpy

或者配合Homebrew 安装，这是官方文档提的方法：

安装python

  $ brew install python
  $ brew linkapps python
  $ which python
  /usr/local/bin/python

用 easy_install 安装或升级pip:

  $ easy_install pip
  $ pip install --upgrade pip

安装 TensorFlow:

  $ pip install tensorflow
  $ pip install tensorflow-gpu # Optional

测试:

  $ python
  >>> import tensorflow as tf

如果上面的方法安装不成功，可尝试下面一行解决，填写最新版本：

pip install tensorflow==1.12.0 --user

关于python版本的问题

#当需要输入python时直接指向python3.5，可以这样处理：
ln -s /usr/local/python3/bin/python3 /usr/bin/python #前面换成你的安装路径

#ps：如果提示 ln: creating symbolic link `/usr/bin/python': File exists
#需要把原来的/usr/bin/python 通过以下命令备份一下
 mv /usr/bin/python /usr/bin/python.bak

#需要恢复原来的python指向的话：
cp /usr/bin/python.bak /usr/bin/python

python3

如果是python3 环境就更方便，但目前tensorflow 只支持 Python 3.4, 3.5, 3.6，如果用brew install python 或 brew install python3 则会安装最新的python3.7，用下面的方法才能安装python3.6 ：

brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/f2a764ef944b1080be64bd88dca9a1d80130c558/Formula/python.rb

此时默认已安装pip3,更新

pip3 install --upgrade pip

安装tensorflow

sudo pip3 install tensorflow

成功安装的包：

$ pip3 list
Package             Version
------------------- -------
absl-py             0.6.1  
astor               0.7.1  
gast                0.2.0  
grpcio              1.17.1 
h5py                2.8.0  
Keras-Applications  1.0.6  
Keras-Preprocessing 1.0.5  
Markdown            3.0.1  
numpy               1.15.4 
pip                 18.1   
protobuf            3.6.1  
setuptools          39.2.0 
six                 1.12.0 
tensorboard         1.12.1 
tensorflow          1.12.0 
termcolor           1.1.0  
Werkzeug            0.14.1 
wheel               0.31.1 

看看tensorflow 的信息：

$ pip show tensorflow
Name: tensorflow
Version: 1.12.0
Summary: TensorFlow is an open source machine learning framework for everyone.
Home-page: https://www.tensorflow.org/
Author: Google Inc.
Author-email: opensource@google.com
License: Apache 2.0
Location: /usr/local/lib/python3.6/site-packages
Requires: six, termcolor, tensorboard, numpy, keras-preprocessing, keras-applications, grpcio, wheel, protobuf, absl-py, astor, gast
Required-by: 

测试：

python3 -c "import tensorflow as tf; tf.enable_eager_execution(); print(tf.reduce_sum(tf.random_normal([1000, 1000])))"

输出：

tf.Tensor(-193.46434, shape=(), dtype=float32)