ReSplit: Improving the Structure of Jupyter Notebooks by Re-Splitting Their Cells

TL;DR

ReSplit is an algorithm that automatically re-splits Jupyter notebook cells to improve their structure, making them more self-contained and easier to understand, based on analysis of code definition-usage chains.

Contribution

The paper introduces ReSplit, a novel algorithm for automatically re-splitting Jupyter notebook cells to enhance their modularity and clarity.

Findings

ReSplit improved notebook structure in 29.5% of cases according to human evaluation.

The algorithm effectively identifies logical boundaries for cell splitting and merging.

Human experts preferred re-split notebooks in nearly a third of cases.

Abstract

Jupyter notebooks represent a unique format for programming - a combination of code and Markdown with rich formatting, separated into individual cells. We propose to perceive a Jupyter Notebook cell as a simplified and raw version of a programming function. Similar to functions, Jupyter cells should strive to contain singular, self-contained actions. At the same time, research shows that real-world notebooks fail to do so and suffer from the lack of proper structure. To combat this, we propose ReSplit, an algorithm for an automatic re-splitting of cells in Jupyter notebooks. The algorithm analyzes definition-usage chains in the notebook and consists of two parts - merging and splitting the cells. We ran the algorithm on a large corpus of notebooks to evaluate its performance and its overall effect on notebooks, and evaluated it by human experts: we showed them several notebooks in their original and the re-split form. In 29.5% of cases, the re-split notebook was selected as the preferred way of perceiving the code. We analyze what influenced this decision and describe several individual cases in detail.