Strange code in python.

Try this:

>>> 2*2
4
>>> _*2
8
>>> print _*3
24
>>> print _*'a'
aaaaaaaa

The tensorflow python module - part 001.

TensorFlow™ is an open source software library for numerical computation using data flow graphs.
I used Fedora 25 distro and python version 2.7.
The base of this installation was the official website.
Fist step of the installation was the base python module: tensorflow.

[root@localhost build]# pip install tensorflow  
Collecting tensorflow
  Downloading tensorflow-1.0.1-cp27-cp27mu-manylinux1_x86_64.whl (44.1MB)
    100% |████████████████████████████████| 44.1MB 30kB/s 
Collecting mock>=2.0.0 (from tensorflow)
  Downloading mock-2.0.0-py2.py3-none-any.whl (56kB)
    100% |████████████████████████████████| 61kB 341kB/s 
Requirement already satisfied: six>=1.10.0 in /usr/lib/python2.7/site-packages (from tensorflow)
Requirement already satisfied: numpy>=1.11.0 in /usr/lib64/python2.7/site-packages (from tensorflow)
Collecting protobuf>=3.1.0 (from tensorflow)
  Downloading protobuf-3.2.0-cp27-cp27mu-manylinux1_x86_64.whl (5.6MB)
    100% |████████████████████████████████| 5.6MB 172kB/s 
Collecting wheel (from tensorflow)
  Downloading wheel-0.29.0-py2.py3-none-any.whl (66kB)
    100% |████████████████████████████████| 71kB 532kB/s 
Collecting funcsigs>=1; python_version < "3.3" (from mock>=2.0.0->tensorflow)
  Downloading funcsigs-1.0.2-py2.py3-none-any.whl
Collecting pbr>=0.11 (from mock>=2.0.0->tensorflow)
  Downloading pbr-2.0.0-py2.py3-none-any.whl (98kB)
    100% |████████████████████████████████| 102kB 518kB/s 
Requirement already satisfied: setuptools in /usr/lib/python2.7/site-packages (from protobuf>=3.1.0->tensorflow)
Installing collected packages: funcsigs, pbr, mock, protobuf, wheel, tensorflow
Successfully installed funcsigs-1.0.2 mock-2.0.0 pbr-2.0.0 protobuf-3.2.0 tensorflow-1.0.1 wheel-0.29.0

The next step come with the installation of python module gpu: tensorflow-gpu.

[root@localhost build]# pip install --upgrade tensorflow-gpu
Collecting tensorflow-gpu
  Downloading tensorflow_gpu-1.0.1-cp27-cp27mu-manylinux1_x86_64.whl (94.8MB)
    100% |████████████████████████████████| 94.8MB 15kB/s 
Requirement already up-to-date: mock>=2.0.0 in /usr/lib/python2.7/site-packages (from tensorflow-gpu)
Requirement already up-to-date: six>=1.10.0 in /usr/lib/python2.7/site-packages (from tensorflow-gpu)
Collecting numpy>=1.11.0 (from tensorflow-gpu)
  Downloading numpy-1.12.0-cp27-cp27mu-manylinux1_x86_64.whl (16.5MB)
    100% |████████████████████████████████| 16.5MB 83kB/s 
Requirement already up-to-date: protobuf>=3.1.0 in /usr/lib64/python2.7/site-packages (from tensorflow-gpu)
Requirement already up-to-date: wheel in /usr/lib/python2.7/site-packages (from tensorflow-gpu)
Requirement already up-to-date: funcsigs>=1; python_version < "3.3" in /usr/lib/python2.7/site-packages (from mock>=2.0.0->tensorflow-gpu)
Requirement already up-to-date: pbr>=0.11 in /usr/lib/python2.7/site-packages (from mock>=2.0.0->tensorflow-gpu)
Collecting setuptools (from protobuf>=3.1.0->tensorflow-gpu)
  Downloading setuptools-34.3.1-py2.py3-none-any.whl (389kB)
    100% |████████████████████████████████| 399kB 637kB/s 
Collecting appdirs>=1.4.0 (from setuptools->protobuf>=3.1.0->tensorflow-gpu)
  Downloading appdirs-1.4.3-py2.py3-none-any.whl
Collecting packaging>=16.8 (from setuptools->protobuf>=3.1.0->tensorflow-gpu)
  Downloading packaging-16.8-py2.py3-none-any.whl
Collecting pyparsing (from packaging>=16.8->setuptools->protobuf>=3.1.0->tensorflow-gpu)
  Downloading pyparsing-2.2.0-py2.py3-none-any.whl (56kB)
    100% |████████████████████████████████| 61kB 577kB/s 
Installing collected packages: numpy, tensorflow-gpu, appdirs, pyparsing, packaging, setuptools
  Found existing installation: numpy 1.11.2
    Uninstalling numpy-1.11.2:
      Successfully uninstalled numpy-1.11.2
  Found existing installation: setuptools 25.1.1
    Uninstalling setuptools-25.1.1:
      Successfully uninstalled setuptools-25.1.1
Successfully installed appdirs-1.4.3 numpy-1.12.0 packaging-16.8 pyparsing-2.2.0 setuptools-34.3.1 tensorflow-gpu-1.0.1

I got errors when I try to run this python module (libcudart.so.8.0).
I have a Intel I5 CPU with a video card without CUDA features.

    _mod = imp.load_module('_pywrap_tensorflow', fp, pathname, description)
ImportError: libcudart.so.8.0: cannot open shared object file: No such file or directory


Failed to load the native TensorFlow runtime.

See https://github.com/tensorflow/tensorflow/blob/master/tensorflow/g3doc/get_started/os_setup.md#import_error

for some common reasons and solutions.  Include the entire stack trace
above this error message when asking for help.

So I used this command to fix with the pip upgrade:

[root@localhost ~]# export TF_BINARY_URL=https://storage.googleapis.com/tensorflow/linux/cpu/tensorflow-0.11.0rc0-cp27-none-linux_x86_64.whl
[root@localhost ~]# pip install --upgrade $TF_BINARY_URL
Collecting tensorflow==0.11.0rc0 from https://storage.googleapis.com/tensorflow/linux/cpu/tensorflow-0.11.0rc0-cp27-none-linux_x86_64.whl
  Downloading https://storage.googleapis.com/tensorflow/linux/cpu/tensorflow-0.11.0rc0-cp27-none-linux_x86_64.whl (39.7MB)
    100% |████████████████████████████████| 39.8MB 37kB/s 
Requirement already up-to-date: mock>=2.0.0 in /usr/lib/python2.7/site-packages (from tensorflow==0.11.0rc0)
Requirement already up-to-date: six>=1.10.0 in /usr/lib/python2.7/site-packages (from tensorflow==0.11.0rc0)
Requirement already up-to-date: numpy>=1.11.0 in /usr/lib64/python2.7/site-packages (from tensorflow==0.11.0rc0)
Collecting protobuf==3.0.0 (from tensorflow==0.11.0rc0)
  Downloading protobuf-3.0.0-cp27-cp27mu-manylinux1_x86_64.whl (5.2MB)
    100% |████████████████████████████████| 5.2MB 206kB/s 
Requirement already up-to-date: wheel in /usr/lib/python2.7/site-packages (from tensorflow==0.11.0rc0)
Requirement already up-to-date: funcsigs>=1; python_version < "3.3" in /usr/lib/python2.7/site-packages (from mock>=2.0.0->tensorflow==0.11.0rc0)
Requirement already up-to-date: pbr>=0.11 in /usr/lib/python2.7/site-packages (from mock>=2.0.0->tensorflow==0.11.0rc0)
Requirement already up-to-date: setuptools in /usr/lib/python2.7/site-packages (from protobuf==3.0.0->tensorflow==0.11.0rc0)
Requirement already up-to-date: appdirs>=1.4.0 in /usr/lib/python2.7/site-packages (from setuptools->protobuf==3.0.0->tensorflow==0.11.0rc0)
Requirement already up-to-date: packaging>=16.8 in /usr/lib/python2.7/site-packages (from setuptools->protobuf==3.0.0->tensorflow==0.11.0rc0)
Requirement already up-to-date: pyparsing in /usr/lib/python2.7/site-packages (from packaging>=16.8->setuptools->protobuf==3.0.0->tensorflow==0.11.0rc0)
Installing collected packages: protobuf, tensorflow
  Found existing installation: protobuf 3.2.0
    Uninstalling protobuf-3.2.0:
      Successfully uninstalled protobuf-3.2.0
  Found existing installation: tensorflow 1.0.1
    Uninstalling tensorflow-1.0.1:
      Successfully uninstalled tensorflow-1.0.1
Successfully installed protobuf-3.0.0 tensorflow-0.11.0rc0

The basic the python tensorflow works, so I need to test.

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

Hello, TensorFlow!