Use inspect to avoid virtual env custom site package pypa/virtualenv#228

tensorflow/g3doc/get_started/os_setup.md

@@ -30,7 +30,7 @@ images are listed in the corresponding installation sections.
 If you encounter installation errors, see
 [common problems](#common-problems) for some solutions.
 
-## Pip Installation 
+## Pip Installation
 
 [Pip](https://en.wikipedia.org/wiki/Pip_(package_manager)) is a package
 management system used to install and manage software packages written in
@@ -80,7 +80,7 @@ $ sudo pip3 install --upgrade https://storage.googleapis.com/tensorflow/mac/tens
 
 You can now [test your installation](#test-the-tensorflow-installation).
 
-## Virtualenv installation 
+## Virtualenv installation
 
 [Virtualenv](http://docs.python-guide.org/en/latest/dev/virtualenvs/) is a tool
 to keep the dependencies required by different Python projects in separate
@@ -170,7 +170,7 @@ $ source ~/tensorflow/bin/activate.csh  # If using csh.
 (tensorflow)$ deactivate
 ```
 
-## Docker installation 
+## Docker installation
 
 [Docker](http://docker.com/) is a system to build self contained versions of a
 Linux operating system running on your machine.  When you install and run
@@ -219,7 +219,7 @@ $ path/to/repo/tensorflow/tools/docker/docker_run_gpu.sh b.gcr.io/tensorflow/ten
 
 You can now [test your installation](#test-the-tensorflow-installation) within the Docker container.
 
-## Test the TensorFlow installation 
+## Test the TensorFlow installation
 
 ### (Optional, Linux) Enable GPU Support
 
@@ -269,7 +269,7 @@ The exact location of the Python library depends on your system, but is usually
 You can find out the directory with the following command:
 
 ```bash
-$ python -c 'import site; print("\n".join(site.getsitepackages()))'
+$ python -c 'import os; import inspect; import tensorflow; print(os.path.dirname(inspect.getfile(tensorflow)))'
 ```
 
 The simple demo model for classifying handwritten digits from the MNIST dataset
@@ -290,7 +290,7 @@ $ python /usr/local/lib/python2.7/dist-packages/tensorflow/models/image/mnist/co
 ...
 ```
 
-## Installing from sources 
+## Installing from sources
 
 When installing from source you will build a pip wheel that you then install
 using pip. You'll need pip for that, so install it as described
@@ -331,7 +331,7 @@ binary path.
 $ sudo apt-get install python-numpy swig python-dev
 ```
 
-#### Configure the installation 
+#### Configure the installation
 
 Run the `configure` script at the root of the tree.  The configure script
 asks you for the path to your python interpreter and allows (optional)
@@ -344,7 +344,7 @@ $ ./configure
 Please specify the location of python. [Default is /usr/bin/python]:
 ```
 
-#### Optional: Install CUDA (GPUs on Linux) 
+#### Optional: Install CUDA (GPUs on Linux)
 
 In order to build or run TensorFlow with GPU support, both Cuda Toolkit 7.0 and
 CUDNN 6.5 V2 from NVIDIA need to be installed.
@@ -376,7 +376,7 @@ sudo cp cudnn-6.5-linux-x64-v2/cudnn.h /usr/local/cuda/include
 sudo cp cudnn-6.5-linux-x64-v2/libcudnn* /usr/local/cuda/lib64
 ```
 
-##### Configure TensorFlow's canonical view of Cuda libraries 
+##### Configure TensorFlow's canonical view of Cuda libraries
 When running the `configure` script from the root of your source tree, select
 the option `Y` when asked to build TensorFlow with GPU support.
 
@@ -491,7 +491,7 @@ best install that too:
 $ sudo easy_install ipython
 ```
 
-#### Configure the installation 
+#### Configure the installation
 
 Run the `configure` script at the root of the tree.  The configure script
 asks you for the path to your python interpreter.
@@ -504,7 +504,7 @@ Please specify the location of python. [Default is /usr/bin/python]:
 Do you wish to build TensorFlow with GPU support? [y/N]
 ```
 
-### Create the pip package and install 
+### Create the pip package and install
 
 ```bash
 $ bazel build -c opt //tensorflow/tools/pip_package:build_pip_package
@@ -546,7 +546,7 @@ Validation error: 7.0%
 ...
 ```
 
-## Common Problems 
+## Common Problems
 
 ### GPU-related issues
 
@@ -635,7 +635,7 @@ copy of Python.
 
 On El Capitan, "six" is a special package that can't be modified, and this
 error is reported when "pip install" tried to modify this package. To fix use
-"ignore_installed" flag, ie
+"ignore_installed" flag e.g.,
 
 sudo pip install --ignore-installed six https://storage.googleapis.com/....