> ## Documentation Index
> Fetch the complete documentation index at: https://leetcode-py.wisl.dev/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> leetcode-py is a Python LeetCode practice environment generator with one CLI: lcpy. It is not a service or platform.
> Each problem is a directory under leetcode/ with README.md, solution.py, test_solution.py, helpers.py, and playground.ipynb. lcpy gen creates them from JSON templates bundled with the package.
> Examples are backed by tests; copy them verbatim.

# Playground Notebook Cells Do Not Render

> Playground files use jupytext percent format, so cells need an editor that understands # %% markers: the VS Code interactive window or JupyterLab with jupytext enabled.

No error is raised. `playground.py` opens as a plain Python file with
`# %%` markers instead of notebook cells. Playgrounds use jupytext
percent format: one `.py` file that behaves as a notebook in the right
editor.

## Fix

* **VS Code**: install the Python extension, then open `playground.py`
  and use *Run Cell* / the interactive window. VS Code understands
  `# %%` natively.
* **JupyterLab**: enable the jupytext contents manager so percent-format
  files open as notebooks.
* **Committed an `.ipynb` by accident**: the repo keeps playgrounds as
  percent-format Python. In a repository checkout, run `bake nb-to-py`
  to convert everything back and delete the `.ipynb` files.

How the playground is meant to be used is covered in
[Notebooks](/practice/notebooks).

Not this problem? Every fix lives on
[Troubleshooting](/troubleshooting).