Fix Python demo and doc. (#4545)

* Remove old doc.
* Fix checking __stdin__.

python-package/README.rst

@@ -4,41 +4,6 @@ XGBoost Python Package
 
 |PyPI version|
 
-Notes
-=====
-
-- Windows users: pip installation may not work on some Windows environments, and it may cause unexpected errors.
-  
-  Installation from pip on Windows is therefore currently disabled for further investigation; please `install from Github <https://xgboost.readthedocs.io/en/latest/build.html>`_ instead.
-- If you want to run XGBoost process in parallel using the fork backend for joblib/multiprocessing, you must build XGBoost without support for OpenMP by ``make no_omp=1``. Otherwise, use the forkserver (in Python 3.4) or spawn backend. See the `sklearn\_parallel.py <../demo/guide-python/sklearn_parallel.py>`__ demo.
-
-Requirements
-============
-
-Since this package contains C++ source code, ``pip`` needs a C++ compiler from the system to compile the source code on-the-fly.
-
-macOS
------
-
-On macOS, ``gcc@5`` is required as later versions remove support for OpenMP. `See here <https://github.com/dmlc/xgboost/issues/1501#issuecomment-292209578>`_ for more info.
-
-Please install ``gcc@5`` from `Homebrew <https://brew.sh/>`_::
-
-    brew install gcc@5
-
-After installing ``gcc@5``, set it as your compiler::
-
-    export CC=gcc-5
-    export CXX=g++-5
-
-Linux
------
-
-Please install ``gcc``::
-
-    sudo apt-get install build-essential      # Ubuntu/Debian
-    sudo yum groupinstall 'Development Tools' # CentOS/RHEL
-
 Installation
 ============
 
@@ -49,28 +14,7 @@ For a stable version, install using ``pip``::
 
     pip install xgboost
 
-From source
------------
-
-For an up-to-date version, `install from Github <https://xgboost.readthedocs.io/en/latest/build.html>`_:
-
--  Run ``./build.sh`` in the root of the repo.
--  Make sure you have `setuptools <https://pypi.python.org/pypi/setuptools>`_ installed: ``pip install setuptools``
--  Install with ``cd python-package; python setup.py install`` from the root of the repo
--  For Windows users, please use the Visual Studio project file under the `Windows folder <../windows/>`_. See also the `installation
-   tutorial <https://www.kaggle.com/c/otto-group-product-classification-challenge/forums/t/13043/run-xgboost-from-windows-and-python>`_ from Kaggle Otto Forum.
--  Add MinGW to the system PATH in Windows if you are using the latest version of xgboost which requires compilation::
-
-    python
-    import os
-    os.environ['PATH'] = os.environ['PATH'] + ';C:\\Program Files\\mingw-w64\\x86_64-5.3.0-posix-seh-rt_v4-rev0\\mingw64\\bin'
-
-Examples
-========
-
--  Refer also to the walk through example in `demo folder <https://github.com/dmlc/xgboost/tree/master/demo/guide-python>`_.
--  See also the `example scripts <https://github.com/dmlc/xgboost/tree/master/demo/kaggle-higgs>`_ for Kaggle
-   Higgs Challenge, including `speedtest script <https://github.com/dmlc/xgboost/tree/master/demo/kaggle-higgs/speedtest.py>`_ on this dataset.
-
 .. |PyPI version| image:: https://badge.fury.io/py/xgboost.svg
    :target: http://badge.fury.io/py/xgboost
+
+For building from source, see `build <https://xgboost.readthedocs.io/en/latest/build.html>`_.

python-package/xgboost/compat.py

@@ -44,7 +44,7 @@ except ImportError:
 # dt
 try:
     # Workaround for #4473, compatibility with dask
-    if sys.__stdin__.closed:
+    if sys.__stdin__ is not None and sys.__stdin__.closed:
         sys.__stdin__ = None
     import datatable