holst

A parser for Jupyter notebooks.

installation

Add the dependency to your shard.yml:

dependencies:
  holst:
    github: ruivieira/crystal-holst

and run shards install.

examples

Parse a Jupyter notebook with Holst::JupyterFile:

require "holst"

notebook = Holst::JupyterFile.new(file_path: "/path/to/notebook.ipynb")

Print the kernel spec and name:

notebook.content.metadata.kernelspec # => "my-python-3.9
notebook.content.metadata.language   # => python

Get all images in a notebook. This returns an array of Bytes that you can save directly to a file.

counter = 1
notebook.images.each { |img|
    File.write("image-#{i}.png", img)
    counter += 1
}

Alternatively, call export_images to bulk save.

notebook.export_images

By default images are save in a sub-folder images with prefix images-$counter.png. You can specify other values.

notebook = Holst::JupyterFile.new(file_path: "/path/to/notebook.ipynb",
    image_prefix: "diagram",
    image_dest: "/some/other/path")

will save images as /some/other/path/diagram-1.png, /some/other/path/diagram-2.png, etc.

compatibility

holst works with Jupyter notebooks with format 4+.

documentation

API documentation is available here.

A git mirror is available at https://git.sr.ht/~ruivieira/crystal-holst.