Lets-Plot Python Package

Requirements

• python >= 3.8 (with dev headers)
• setuptools (pip install setuptools)
• build (pip install build)

Configuration

Edit local.properties in the project root:

• architecture - set to arm64 or x86_64 depending on your Python architecture.
• enable_python_package - set to true for working with Python package.
• python.include_path - path to Python include directory where Python.h located. To get this path you can run python -c "from sysconfig import get_paths as gp; print(gp()['include'])".
• python.bin_path - path to your Python bin directory. To get this path you can run python -c "from sysconfig import get_paths as gp; print(gp()['scripts'])".

Building

There are two ways to build the Python package:

1. Full Build with Gradle

This method builds both the Kotlin multiplatform binaries and the Python package:

./gradlew :python-package-build:build

Note: The target Python version for this build is determined by the configuration in local.properties file (see Configuration section above).

2. Python Package Only Build

If you've only made changes to Python code, you can rebuild just the Python wheel:

python -m build -w

Prerequisites for Python build:

• Must be in the python-package directory
• Need an active Python environment with the build package installed
• The resulting wheel will target the Python version of your active environment

Installing locally

• change dir to lets-plot/python-package
• create / activate Python environment (if needed)
• run shell command:

pip install --no-index --find-links=dist/ lets-plot --no-deps --force-reinstall

Test in Jupyter

When the "dev" version is built, lets-plot embeds current "dev" js into Jupyter notebook.

If necessary, this default can be temporarily overwritten by editing dev_xxx settings in _global_settings.py

The "dev" version of JS library can be served from js-package/build/dist/js/developmentExecutable folder (in js-package project):

$ cd lets-plot

# Build developened JS package:
$ ./gradlew js-package:jsBrowserDevelopmentWebpack
  
# Start local web-server to serve dev js script:
$ python -m http.server 8080

Example code

from lets_plot import *
data = dict(time=['Lunch', 'Lunch', 'Dinner', 'Dinner', 'Dinner'])
p = ggplot(data) + geom_bar(aes(x='time', fill='..count..'))
p += scale_fill_hue()
p