🌰 walnut

Offline coding-practice CLI for terminal-native practice.

Offline coding-practice CLI I built because nothing kills practice momentum like spotty Wi-Fi on a flight or terrible hotel internet.

Local problems, test runner, starter templates, reference solutions, cheat sheets, progress tracking. Terminal-native. Stays on your machine.

What You Get

• Browse and practice a roadmap based on the public NeetCode 150 ordering from the terminal.
• Start each problem from a local starter.py.
• Write private attempts in ignored solution.py files.
• Run local tests and track progress under .walnut/.
• Use cheat sheets and reference solutions when you need a nudge.

Only the first 14 problems are fully seeded with statements, local tests, and reference solutions right now: Arrays & Hashing plus Two Pointers. The rest are roadmap entries with metadata, links, placeholder statements, and starters.

Requirements

• Python 3.9+ with working venv and pip.
• On Debian/Ubuntu, install venv support with sudo apt install python3-venv.
• bash for the setup installer.
• macOS or Linux.
• Windows users should use WSL.
• Internet once during ./setup to install rich and textual.
• Core practice is fully offline after setup.

Quick Start

Install from the repo root:

./setup

Then open Walnut:

export PATH="$HOME/.local/bin:$PATH"
walnut

After setup, walnut can run from any directory. The cloned repo stays the source of truth for the app, problem library, local progress, notes, and attempts.

In an interactive terminal, plain walnut opens the browse interface. Use walnut home for the static dashboard, or walnut tui when you want to be explicit.

./setup creates .venv/, installs Walnut in editable mode, writes a ~/.local/bin/walnut wrapper, pins that wrapper to this repo with WALNUT_HOME, and runs doctor plus verify --all. It does not edit your shell profile by default. It prints the one PATH line you can add yourself. Pass --modify-profile if you want it to add that line to your shell profile. Re-running setup is safe.

Practice Flow

Open the browse interface:

walnut

From there:

1. Use j/k to move around the list.
2. Press [ or ] to switch between topics and the full problem list.
3. Press enter on a topic to drill in.
4. Highlight a problem and press s to start it.
5. Press e to open the selected solution.py.
6. Press t to run local tests.
7. Press n to open private notes.
8. Press c to open the cheat sheet.

You can also do the same flow with direct commands:

walnut topics
walnut list arrays-and-hashing
walnut show 3
walnut pick 3

Write your answer in the generated solution.py file:

problems/01-arrays-and-hashing/03-two-sum/solution.py

Run it locally:

walnut test 3 --perf

Use a dry run when you do not want to update progress:

walnut run 3 --perf

Useful Commands

What you need	Command
Check setup	walnut doctor
Show topics	walnut topics
List a topic	walnut list two-pointers
Read a problem	walnut show 3
Start solving	walnut pick 3
Open solution in editor	walnut edit 3
Run tests	walnut test 3 --perf
Get next hint	walnut hint 3
Show reference solution	walnut solution 3
Pick the next unsolved problem	walnut next
Reset local attempt/progress for a problem	walnut reset 3
Print private notes path	walnut notes 3
Open private notes in editor	walnut notes 3 --open
Open a cheat sheet	walnut cheat 3
Print official links	walnut open-official 3 --print
Verify seeded solutions	walnut verify --all --plain

Terminal UI

walnut

walnut tui opens the same interface explicitly.

Key shortcuts:

j/k       move
[/]       switch tabs
enter     open a topic
s         start the selected problem
e         open selected solution.py
t         run local tests
r         reset the active timer
n         open notes
c         open the cheat sheet
esc       go back one layer
/         filter
q         quit

If you prefer another shell or pane, run tests there with walnut test <id> --perf. The TUI picks up the latest progress within a second.

Recommended Tmux Workflow

Walnut is designed around a multi-pane terminal workflow. Tmux is the recommended setup, but it is not required. Ghostty tabs, iTerm panes, or any setup with separate terminal windows work too.

The layout I use is:

walnut
  home    runs `walnut`
  editor  opens the selected solution.py when I press e
  notes   opens the selected notes.md when I press n

Create that layout manually:

tmux new-session -d -s walnut -n home -c "$PWD"
tmux new-window -t walnut -n editor -c "$PWD"
tmux new-window -t walnut -n notes -c "$PWD"
tmux send-keys -t walnut:home 'walnut' C-m
tmux attach -t walnut

The session is auto-detected and the target window names default to editor and notes. The WALNUT_TMUX_* variables are only needed if your session or window names differ from that layout:

WALNUT_TMUX_SESSION=walnut \
WALNUT_TMUX_EDITOR_WINDOW=editor \
WALNUT_TMUX_NOTES_WINDOW=notes \
walnut

Inside that setup, e sends the selected solution.py to the editor window, and n sends the selected notes.md to the notes window. The tmux integration expects nvim to be available, or an already-running vim, vi, or nvim in the target window. Without tmux, those keys show the file path so you can open it however you like.

What Stays Local

Your practice work is intentionally ignored by git:

**/solution.py
**/notes.md
.walnut/

That means your attempts, notes, timers, and progress stay on your machine. A fresh clone starts clean.

Cheat Sheets

Per-topic cheat sheets live in docs/cheatsheets/. They cover all 18 roadmap topics plus python-stdlib and complexity.

walnut cheat --list
walnut cheat arrays-and-hashing
walnut cheat python
walnut cheat complexity

If walnut Is Not Found

See the full PATH fix in Quickstart.

More Docs

• Quickstart
• Repo guide

Attribution and Content Policy

Walnut is an independent learning tool and is not affiliated with, endorsed by, or sponsored by LeetCode or NeetCode.

walnut sync-roadmap refreshes public roadmap metadata only: titles, topic labels, difficulty, LeetCode IDs, and links.

This project links to LeetCode problem pages and follows the public NeetCode 150 ordering for navigation. LeetCode and NeetCode own their respective names, websites, problem pages, explanations, videos, editorials, and other content.

Walnut does not copy or redistribute LeetCode or NeetCode problem statements, explanations, videos, paid content, editorials, or solution text. Seeded prompts, examples, local test cases, hints, and reference solutions in this repo are original Walnut practice material. For official problem text, use the linked LeetCode or NeetCode pages.