TensorFlow似乎没有安装

我有这些警告：

2017-09-26 14：50：45.956966：W tensorflow / core / platform / cpu_feature_guard.cc：45] TensorFlow库未编译为使用SSE4.2指令，但这些指令可在您的计算机上使用并且可以加速CPU计算 . 2017-09-26 14：50：45.956986：W tensorflow / core / platform / cpu_feature_guard.cc：45] TensorFlow库未编译为使用AVX指令，但这些指令可在您的计算机上使用，并可加速CPU计算 . 2017-09-26 14：50：45.956990：W tensorflow / core / platform / cpu_feature_guard.cc：45] TensorFlow库未编译为使用AVX2指令，但这些指令可在您的计算机上使用，并可加速CPU计算 . 2017-09-26 14：50：45.956996：W tensorflow / core / platform / cpu_feature_guard.cc：45] TensorFlow库未编译为使用FMA指令，但这些指令可在您的计算机上使用，并可加速CPU计算 .

所以，根据我在互联网上找到的内容，我接着点了这个链接：

https://www.tensorflow.org/install/install_sources

但是，当我尝试：

$ python

并且：

# Python
import tensorflow as tf
hello = tf.constant('Hello, TensorFlow!')
sess = tf.Session()
print(sess.run(hello))

输出应为： Hello, TensorFlow!

但是，我根本得不到这个......

emixam23@pt-mguittet:~/Workspace$ python
Python 3.6.2 (default, Sep  4 2017, 16:58:35) 
[GCC 4.2.1 Compatible Apple LLVM 8.1.0 (clang-802.0.42)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

>>> import tensorflow as tf
>>> hello = tf.constant('Hello, TensorFlow!')
>>> sess = tf.Session()
2017-09-26 14:56:33.905065: W tensorflow/core/platform/cpu_feature_guard.cc:45] The TensorFlow library wasn't compiled to use SSE4.2 instructions, but these are available on your machine and could speed up CPU computations.
2017-09-26 14:56:33.905096: W tensorflow/core/platform/cpu_feature_guard.cc:45] The TensorFlow library wasn't compiled to use AVX instructions, but these are available on your machine and could speed up CPU computations.
2017-09-26 14:56:33.905105: W tensorflow/core/platform/cpu_feature_guard.cc:45] The TensorFlow library wasn't compiled to use AVX2 instructions, but these are available on your machine and could speed up CPU computations.
2017-09-26 14:56:33.905112: W tensorflow/core/platform/cpu_feature_guard.cc:45] The TensorFlow library wasn't compiled to use FMA instructions, but these are available on your machine and could speed up CPU computations.
>>> print(sess.run(hello))
b'Hello, TensorFlow!'
>>>

即使在我安装它之后，我仍然有警告，为什么呢？我使用了Xcode 7.3，但我没有把GPU放在 ./configuration 进程中 .

任何的想法？ ：/ 预先感谢 ！