# Installation¶

This page describes how to install datatable on various systems.

## Prerequisites¶

Python 3.6+ is required. You can check your python version via

$python --version Python 3.6.6  In addition, we recommend using pip version 20.0+, especially if you’re planning to install datatable from the source, or if you are on a Unix machine. $ pip --version pip 19.3.1 from /home/pasha/py36/lib/python3.6/site-packages/pip (python 3.6) $pip install pip --upgrade Collecting pip Using cached https://files.pythonhosted.org/.../pip-20.1.1-py2.py3-none-any.whl Installing collected packages: pip Found existing installation: pip 19.3.1 Uninstalling pip-19.3.1: Successfully uninstalled pip-19.3.1 Successfully installed pip-20.1.1  There are no other prerequisites. Datatable does not depend on any other python module 1, nor on any non-standard system library. ## Basic installation¶ On most platforms datatable can be installed directly from PyPI using pip: $ pip install datatable 

The following platforms are supported:

• macOS

Datatable has been tested to work on macOS 10.12.5 (Sierra), macoS 10.13.6 (High Sierra), and macOS 10.15.7 (Catalina).

• Linux x86_64 / ppc64le

We produce binary wheels that are tagged as manylinux2010 (for x86_64 architecture) and manylinux2014 (for ppc64le). Consequently, they will work with your Linux distribution if it is compatible with one of these tags. Please refer to PEP 513 and PEP 599 for details.

• Windows

Windows wheels are available for Windows 10 or later.

## Install latest dev version¶

If you wish to test the latest version of datatable before it has been officially released, then you can use one of the binary wheels that we build as part of our Continuous Integration process.

If you are on Windows, then pre-built wheels are available on AppVeyor. Click on a green main build of your choice, then navigate to the “Artifacts” tab, copy the wheel URL that corresponds to your Python version, and finally install it as:

C:\> pip install YOUR_WHEEL_URL 

For macOS and Linux, development wheels can be found at our S3 repository. Scroll to the bottom of the page to find the latest links, and then download or copy the URL of a wheel that corresponds to your Python version and platform. This wheel can be installed with pip as usual:

$pip install YOUR_WHEEL_URL  Alternatively, you can instruct pip to go to that repository directly and find the latest version automatically: $ pip install --trusted-host h2o-release.s3-website-us-east-1.amazonaws.com \ -i http://h2o-release.s3-website-us-east-1.amazonaws.com/ datatable 

## Build from source¶

In order to build and install the latest development version of datatable directly from GitHub, run the following command:

$pip install git+https://github.com/h2oai/datatable  Since datatable is written mostly in C++, your computer must be set up for compiling C++ code. The build script will attempt to find the compiler automatically, searching for GCC, Clang, or MSVC on Windows. If it fails, or if you want to use some other compiler, then set environment variable CXX before building the code. Datatable uses C++14 language standard, which means you must use the compiler that fully implements this standard. The following compiler versions are known to work: • Clang 5+; • GCC 6+; • MSVC 19.14+. ## Install datatable in editable mode¶ If you want to tweak certain features of datatable, or even add your own functionality, you are welcome to do so. This section describes how to install datatable for development process. 1. First, you need to fork the repository and then clone it locally: $ git clone https://github.com/your_user_name/datatable $cd datatable  2. Build _datatable core library. The two most common options are: $ # build a "production mode" datatable $make build$ # build datatable in "debug" mode, without optimizations and with $# internal asserts enabled$ make debug 

Note that you would need to have a C++ compiler in order to compile and link the code. Please refer to the previous section for compiler requirements.

On macOS you may also need to install Xcode Command Line Tools.

On Linux if you see an error that 'Python.h' file not found, then it means you need to install a “development” version of Python, i.e. the one that has python header files included.

3. After the previous step succeeds, you will have a _datatable.*.so file in the src/datatable/lib folder. Now, in order to make datatable usable from Python, run

$echo "pwd/src" >>${VIRTUAL_ENV}/lib/python*/site-packages/easy-install.pth 

(This assumes that you are using a virtualenv-based python. If not, then you’ll need to adjust the path to your python’s site-packages directory).

4. Install additional libraries that are needed to test datatable:

$pip install -r requirements_tests.txt$ pip install -r requirements_extra.txt $pip install -r requirements_docs.txt  5. Check that everything works correctly by running the test suite: $ make test 

Once these steps are completed, subsequent development process is much simpler. After any change to C++ files, re-run make build (or make debug) and then restart python for the changes to take effect.

Datatable only recompiles those files that were modified since the last time, which means that usually the compile step takes only few seconds. Also note that you can switch between the “build” and “debug” versions of the library without performing make clean.

## Troubleshooting¶

Despite our best effort to keep the installation process hassle-free, sometimes problems may still arise. Here we list some of the more frequent ones, where we know how to resolve them. If none of these help you, please ask a question on StackOverflow (tagging with [py-datatable]), or file an issue on GitHub.

pip._vendor.pep517.wrappers.BackendUnavailable

This error occurs when you have an old version of pip in your environment. Please upgrade pip to the version 20.0+, and the error should disappear.

ImportError: cannot import name '_datatable'

This means the internal core library _datatable.*.so is either missing entirely, is in a wrong location, or has the wrong name. The first step is therefore to find where that file actually is. Use the system find tool, limiting the search to your python directory.

If the file is missing entirely, then it was either deleted, or installation used a broken wheel file. In either case, the only solution is to rebuild or reinstall the library completely.

If the file is present but not within the site-packages/datatable/lib/ directory, then moving it there should solve the issue.

If the file is present and is in the correct directory, then there must be a name conflict. In python run:

import sysconfig sysconfig.get_config_var("SOABI") 
'cpython-36m-ppc64le-linux-gnu'

The reported suffix should match the suffix of the _datatable.*.so file. If it doesn’t, then renaming the file will fix the problem.

Python.h: no such file or directory when compiling from source

Your Python distribution was shipped without the Python.h header file. This has been observed on certain Linux machines. You would need to install a Python package with a -dev suffix, for example python3.6-dev.

fatal error: 'sys/mman.h' file not found on macOS

In order to compile from source on mac computers, you need to have Xcode Command Line Tools installed. Run:

\$ xcode-select --install 
ImportError: This package should not be accessible

The most likely cause of this error is a misconfigured PYTHONPATH environment variable. Unset that variable and try again.

Footnotes

1

Since version v0.11.0