Getting Set Up

The Bokeh project encompasses two major components: the Bokeh package source code, written in Python, and the BokehJS client-side library, written in CoffeeScript and TypeScript. Accordingly, development of Bokeh is slightly complicated by the explicit compilation step required to generate deployable JavaScript.

For this reason, in order to develop Bokeh from a source checkout, you must first be able to build BokehJS. This chapter will walk you through getting a full development environment set up.

Preliminaries

Git

The Bokeh source code is stored in a Git source control repository. The first step to working on Bokeh is to install Git on to your system. There are different ways to do this depending on whether, you are using Windows, OSX, or Linux.

To install Git on any platform, refer to the Installing Git section of the Pro Git Book.

Conda

Developing Bokeh requires installing some software packages that are not Python packages (e.g. Selenium, nodejs, etc.). To make this more manageable, core developers rely heavily on the conda package manager for the free Anaconda Python distribution. However, conda can also install non-Python package dependencies, which helps streamline Bokeh development greatly. It is strongly recommended that anyone developing Bokeh also use conda, and the remainder of the instructions will assume that conda is available.

To install Conda on any platform, see the Download conda section of the conda documentation.

Cloning the Repository

The source code for the Bokeh project is hosted on GitHub. To clone the source repository, issue the following command:

git clone https://github.com/bokeh/bokeh.git

This will create a bokeh directory at your file system location. This bokeh directory is referred to as the source checkout for the remainder of this document.

Installing Dependencies

Bokeh requires many additional packages for development and testing. Many of these are on the main Anaconda default channel, but others are only available from additional conda channels, or via the Node Package Manager.

Conda Packages

On all platforms, execute the following two commands at your command prompt to add the “bokeh” and “conda-forge” channels to your list of package sources:

conda config --append channels bokeh
conda config --append channels conda-forge

Note

If you do not wish to make configuration changes to your conda configuration, then the channels above can be added on a per-command basis with the -c command line option to conda, e.g. conda install -c bokeh -c conda-forge <pkgs>

It’s also necessary to install jinja2 and pyyaml first, to bootstrap the rest of these instructions. To do that, execute:

conda install jinja2 pyyaml

From the top level of the source checkout directory, execute the following command at your command prompt to install all the required packages:

  • OSX / Linux

    conda install `python scripts/deps.py build run test`
    

    Note the required backticks in the command.

  • Windows (Powershell)

    conda install $(python scripts/deps.py build run).split() | where {$_}
    
  • Winows (DOS Command Prompt)

    for /F "delims=" %i in ('python scripts\deps.py build run') do (conda install %i)
    

Note

The test category has been omitted from the Windows installs above because not all of the testing packages are easily installable on Windows yet. The commands above will install everything necessary to build and run, however. If you are interested in helping out and becoming a Windows maintainer for Bokeh, please contact the developers.

Node Packages

Building BokehJS also requires installing JavaScript dependencies using the Node Package Manager. If you have followed the instructions above, conda has already installed the necessary npm and node.js packages to your system.

Starting from the top level of the source checkout directory, execute the following commands

cd bokehjs
npm install

This command will install the necessary packages into the node_modules subdirectory.


Typically, these instructions only need to be followed once, when you are first getting set up. Occasionally, however, dependencies may be added or changed, in which case these instructions will need to be followed again.

Configuring Git

There are a few configurations you can make locally that will help make working with the repository safer and easier.

Note

The optional instructions in this section are specific to OSX and Linux.

Git Hooks

In order to help prevent some accidental errors, here are some git hooks that may be useful. The scripts below should be placed in the .git/hooks subdirectory in the top level of the source checkout directory and be marked executable with e.g. chmod +x pre-commit. For more information on git hooks, see this turorial.

pre-commit

This git hook runs the code quality tests before allowing a commit to proceed. Note that all the standard testing dependencies must be installed in order for this hook to function.

#!/bin/bash

py.test -m quality
exit $?

pre-push

This git hook prevents accidental pushes to master on GitHub.

#!/bin/bash

protected_branch='master'
current_branch=$(git symbolic-ref HEAD | sed -e 's,.*/\(.*\),\1,')

if [ $protected_branch = $current_branch ]
then
    read -p "You're about to push master, is that what you intended? [y|n] " -n 1 -r < /dev/tty
    echo
    if echo $REPLY | grep -E '^[Yy]$' > /dev/null
    then
        exit 0 # push will execute
    fi
    exit 1 # push will not execute
else
    exit 0 # push will execute
fi

Git Aliases

There are also some useful aliases that can be added to the .gitconfig file located in your home directory.

The following alias adds a git resolve command that will automatically open up your editor to resolve any merge conflicts.

[alias]
    resolve = !sh -c 'vim -p $(git status -s | grep "^UU" | cut -c4-)'

You can replace vim with whatever your favorite editor command is.

Building and Installing

Once you have all the required depencies installed, the simplest way to build and install Bokeh and BokehJS is to use the setup.py script at the top level of the source checkout directory.

The setup.py script has two main modes of operation:

python setup.py install

Bokeh will be installed in your Python site-packages directory. In this mode, any changes to the python source code will not show up until setup.py install is run again.

python setup.py develop

A bokeh.pth path file will be written to your Python site-packages directory that points to the bokeh subdirectory of your source checkout. Any changes you make to the python source code will be available immediately without any additional steps.

With either mode, you will be prompted for how to install BokehJS, e.g.:

python setup.py develop

Bokeh includes a JavaScript library (BokehJS) that has its own
build process. How would you like to handle BokehJS:

1) build and install fresh BokehJS
2) install last built BokehJS from bokeh/bokehjs/build

Choice?

You may skip this prompt by supplying the appropriate command line option to setup.py, e.g.

  • python setup.py develop --build-js
  • python setup.py develop --install-js

Note that you will need to build BokehJS any time that the BokehJS source code changes (either by you or by pulling new revisions from GitHub). In particular, at the very least, you must build BokehJS the first time you install.

Note

Occasionally the list of JavaScript dependencies also changes. If this occurs, you will also need to re-run the instructions in the Node Packages section above.

Next Steps

You can check that everything is installed and set up correctly by executing the command:

python -m bokeh info

You should see output similar to:

Python version      :  3.6.1 |Anaconda, Inc.| (default, May 11 2017, 13:04:09)
IPython version     :  5.3.0
Bokeh version       :  0.12.7dev3-17-g184f1ed7a
BokehJS static path :  /Users/bryan/work/bokeh/bokeh/server/static
node.js version     :  v6.10.3
npm version         :  3.10.10

The next check that can be made is to run some of the examples. There are different ways in which bokeh can be used which suit a variety of use cases.

To create an html file,

BOKEH_RESOURCES=inline python examples/plotting/file/iris.py

which will create a file iris.html locally and open up a web browser.

../../_images/bokeh_iris_html.png

The variable BOKEH_RESOURCES determines where the css and JavaScript resources required by bokeh are found. By specifying inline we are using the version of BokehJS we just built to include the resources inline as part of the html file. The BOKEH_RESOURCES variable is required as the default behaviour is to use CDN resources.

Another method of running bokeh is as a server. An example of this mode of operation can be run using the command

python -m bokeh serve --show examples/app/sliders.py

which will open up a browser with an interactive figure.

../../_images/bokeh_app_sliders.png

All the sliders allow interactive control of the sine wave, with each update redrawing the line with the new parameters. The --show option opens the web browser to the appropriate address, the default is localhost:5006.

If you have any problems with the steps here, please contact the developers.