LightGBM Python Package
=======================

|License| |Python Versions| |PyPI Version|

Installation
------------

Preparation
'''''''''''

`setuptools <https://pypi.python.org/pypi/setuptools>`_ is needed.

For macOS users, gcc with OpenMP support must be installed first. Refer to `Installation Guide <https://github.com/Microsoft/LightGBM/blob/master/docs/Installation-Guide.rst#macos>`__ for installing gcc with OpenMP support.

Note: 32-bit Python is not supported. Please install 64-bit version.

Install from `PyPI <https://pypi.python.org/pypi/lightgbm>`_ Using ``pip``
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
For Windows users, `VC runtime <https://go.microsoft.com/fwlink/?LinkId=746572>`_ is needed if Visual Studio (2015 or 2017) is not installed.

Install `wheel <http://pythonwheels.com>`_ via ``pip install wheel`` first. After that download the wheel file and install from it:

.. code:: sh

    pip install lightgbm

Build from Sources
******************

.. code:: sh

    pip install --no-binary :all: lightgbm

For Linux and macOS users, installation from sources requires installed `CMake <https://cmake.org/>`_.

For macOS users, you need to specify compilers by runnig ``export CXX=g++-7 CC=gcc-7`` first.

For Windows users, Visual Studio (or `MS Build <https://www.visualstudio.com/downloads/>`_) is needed. If you get any errors during installation, you may need to install `CMake <https://cmake.org/>`_ (version 3.8 or higher).

Build GPU Version
~~~~~~~~~~~~~~~~~

.. code:: sh

    pip install lightgbm --install-option=--gpu

For Windows users, `CMake <https://cmake.org/>`_ (version 3.8 or higher) is strongly required in this case.

Note: Boost and OpenCL are needed: details for installation can be found in `Installation Guide <https://github.com/Microsoft/LightGBM/blob/master/docs/Installation-Guide.rst#build-gpu-version>`__. You need to add ``OpenCL_INCLUDE_DIR`` to the environmental variable **'PATH'** and export ``BOOST_ROOT`` before installation.

Build with MinGW-w64 on Windows
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code:: sh

    pip install lightgbm --install-option=--mingw

Note: `CMake <https://cmake.org/>`_ and `MinGW-w64 <https://mingw-w64.org/>`_ should be installed first.

Install from GitHub
'''''''''''''''''''

For Linux and macOS users, installation from GitHub requires installed `CMake <https://cmake.org/>`_.

For Windows users, Visual Studio (or `MS Build <https://www.visualstudio.com/downloads/>`_) is needed. If you get any errors during installation and there is the warning ``WARNING:LightGBM:Compilation with MSBuild from existing solution file failed.`` in the log, you should install `CMake <https://cmake.org/>`_ (version 3.8 or higher).

.. code:: sh

    git clone --recursive https://github.com/Microsoft/LightGBM.git
    cd LightGBM/python-package
    # export CXX=g++-7 CC=gcc-7  # for macOS users only
    python setup.py install

Note: ``sudo`` (or administrator rights in Windows) may be needed to perform the command.

Run ``python setup.py install --mingw`` if you want to use MinGW-w64 on Windows instead of Visual Studio. `CMake <https://cmake.org/>`_ and `MinGW-w64 <https://mingw-w64.org/>`_ should be installed first.

Run ``python setup.py install --gpu`` to enable GPU support. For Windows users, `CMake <https://cmake.org/>`_ (version 3.8 or higher) is strongly required in this case. Boost and OpenCL are needed: details for installation can be found in `Installation Guide <https://github.com/Microsoft/LightGBM/blob/master/docs/Installation-Guide.rst#build-gpu-version>`__.

If you get any errors during installation or due to any other reason, you may want to build dynamic library from sources by any method you prefer (see `Installation Guide <https://github.com/Microsoft/LightGBM/blob/master/docs/Installation-Guide.rst>`__) and then run ``python setup.py install --precompile``.

Examples
--------

Refer to the walk through examples in `Python guide folder <https://github.com/Microsoft/LightGBM/tree/master/examples/python-guide>`_.

Troubleshooting
---------------

Refer to `FAQ <https://github.com/Microsoft/LightGBM/tree/master/docs/FAQ.rst>`_.

Developments
------------

The code style of Python-package follows `pep8 <https://www.python.org/dev/peps/pep-0008/>`_. If you would like to make a contribution and not familiar with pep-8, please check the pep8 style guide first. Otherwise, the check won't pass. You should be careful about:

- E1 Indentation (check pep8 link above)
- E202 whitespace before and after brackets
- E225 missing whitespace around operator
- E226 missing whitespace around arithmetic operator
- E261 at least two spaces before inline comment
- E301 expected 1 blank line in front of and at the end of a method
- E302 expected 2 blank lines in front of and at the end of a function or a class

E501 can be ignored (line too long).

.. |License| image:: https://img.shields.io/badge/license-MIT-blue.svg
   :target: https://github.com/Microsoft/LightGBM/blob/master/LICENSE
.. |Python Versions| image:: https://img.shields.io/pypi/pyversions/lightgbm.svg
   :target: https://pypi.python.org/pypi/lightgbm
.. |PyPI Version| image:: https://badge.fury.io/py/lightgbm.svg
   :target: https://badge.fury.io/py/lightgbm
