32-bit Python is not supported. Please install 64-bit version. If you have a strong need to install with 32-bit Python, refer to `Build 32-bit Version with 32-bit Python section <#build-32-bit-version-with-32-bit-python>`__.
For **Windows** users, `VC runtime <https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads>`_ is needed if **Visual Studio** (2015 or newer) is not installed.
- Starting from version 2.2.1, the library file in distribution wheels is built by the **Apple Clang** (Xcode_8.3.3) compiler. This means that you don't need to install the **gcc** compiler anymore. Instead of that you need to install the **OpenMP** library, which is required for running LightGBM on the system with the **Apple Clang** compiler. You can install the **OpenMP** library by the following command: ``brew install libomp``.
- For version smaller than 2.2.1 and not smaller than 2.1.2, **gcc-8** with **OpenMP** support must be installed first. Refer to `Installation Guide <https://github.com/microsoft/LightGBM/blob/master/docs/Installation-Guide.rst#gcc>`__ for installation of **gcc-8** with **OpenMP** support.
- In case you prefer **Apple Clang**, you should install **OpenMP** (details for installation can be found in `Installation Guide <https://github.com/microsoft/LightGBM/blob/master/docs/Installation-Guide.rst#apple-clang>`__) first and **CMake** version 3.12 or higher is required.
In some cases **OpenMP** cannot be found which causes installation failures. So, if you encounter errors during the installation process, try to pass paths to **CMake** via ``pip`` options, like
- In case you prefer **gcc**, you need to install it (details for installation can be found in `Installation Guide <https://github.com/microsoft/LightGBM/blob/master/docs/Installation-Guide.rst#gcc>`__) and specify compilers by running ``export CXX=g++-7 CC=gcc-7`` (replace "7" with version of **gcc** installed on your machine) first.
For **Windows** users, **Visual Studio** (or `VS Build Tools <https://visualstudio.microsoft.com/downloads/>`_) is needed. If you get any errors during installation, you may need to install `CMake`_ (version 3.8 or higher).
**MPI** libraries are needed: details for installation can be found in `Installation Guide <https://github.com/microsoft/LightGBM/blob/master/docs/Installation-Guide.rst#build-mpi-version>`__.
**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>`__. Almost always you also need to pass ``OpenCL_INCLUDE_DIR``, ``OpenCL_LIBRARY`` options for **Linux** and ``BOOST_ROOT``, ``BOOST_LIBRARYDIR`` options for **Windows** to **CMake** via ``pip`` options, like
For more details see `FindBoost <https://cmake.org/cmake/help/latest/module/FindBoost.html>`__ and `FindOpenCL <https://cmake.org/cmake/help/latest/module/FindOpenCL.html>`__.
It is recommended to use **Visual Studio** for its better multithreading efficiency in **Windows** for many-core systems
(see `Question 4 <https://github.com/microsoft/LightGBM/blob/master/docs/FAQ.rst#4-i-am-using-windows-should-i-use-visual-studio-or-mingw-for-compiling-lightgbm>`__ and `Question 8 <https://github.com/microsoft/LightGBM/blob/master/docs/FAQ.rst#8-cpu-usage-is-low-like-10-in-windows-when-using-lightgbm-on-very-large-datasets-with-many-core-systems>`__).
By default, installation in environment with 32-bit Python is prohibited. However, you can remove this prohibition on your own risk by passing ``bit32`` option.
It is **strongly not recommended** to use this version of LightGBM!
For **macOS** users who compile with **Apple Clang**, to pass **OpenMP** paths to **CMake** use the following syntax: ``python setup.py install --openmp-include-dir=/usr/local/opt/libomp/include/ --openmp-library=/usr/local/opt/libomp/lib/libomp.dylib``.
For **Windows** users, 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`_ (version 3.8 or higher).
# export CXX=g++-7 CC=gcc-7 # macOS users, if you decided to compile with gcc, don't forget to specify compilers (replace "7" with version of gcc installed on your machine)
Run ``python setup.py install --nomp`` to disable **OpenMP** support. All remarks from `Build Threadless Version section <#build-threadless-version>`__ are actual in this case.
Run ``python setup.py install --mpi`` to enable **MPI** support. All remarks from `Build MPI Version section <#build-mpi-version>`__ are actual in this case.
Run ``python setup.py install --mingw``, if you want to use **MinGW-w64** on **Windows** instead of **Visual Studio**. All remarks from `Build with MinGW-w64 on Windows section <#build-with-mingw-w64-on-windows>`__ are actual in this case.
Run ``python setup.py install --gpu`` to enable GPU support. All remarks from `Build GPU Version section <#build-gpu-version>`__ are actual in this case. To pass additional options to **CMake** use the following syntax: ``python setup.py install --gpu --opencl-include-dir=/usr/local/cuda/include/``, see `Build GPU Version section <#build-gpu-version>`__ for the complete list of them.
Run ``python setup.py install --hdfs`` to enable HDFS support. All remarks from `Build HDFS Version section <#build-hdfs-version>`__ are actual in this case.
Run ``python setup.py install --bit32``, if you want to use 32-bit version. All remarks from `Build 32-bit Version with 32-bit Python section <#build-32-bit-version-with-32-bit-python>`__ are actual in this case.
If you get any errors during installation or due to any other reasons, 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 just run ``python setup.py install --precompile``.
In case you are facing any errors during the installation process, you can examine ``$HOME/LightGBM_compilation.log`` file, in which all operations are logged, to get more details about occurred problem. Also, please attach this file to the issue on GitHub to help faster indicate the cause of the error.
The code style of Python-package follows `PEP 8 <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 PEP 8 style guide first. Otherwise, the check won't pass. Only E501 (line too long) and W503 (line break occurred before a binary operator) can be ignored.
