Grinding LeetCode in a bare editor means writing if __name__ == "__main__"
prints, losing your test cases between attempts, and having nothing to show
for a solved problem. leetcode-py generates a real software project per
problem, tests, helpers, docs, and tooling included, so practice looks
like the engineering you already do.
Tests come with the problem
Every generated problem ships a parametrized pytest suite with 10+ cases,
including edge cases, and a run_helper/assert_helper pair that keeps
inputs readable in failure output. You never write test scaffolding; you only
ever make red go green. Multiple solution approaches to the same problem?
One test suite covers all of them via
parametrized classes.
Data structures you can see
TreeNode, ListNode, GraphNode, and DictTree convert between LeetCode’s
array format and live objects, and render themselves as diagrams in Jupyter
or clean ASCII in the terminal. Debugging a twisted tree traversal is much
shorter when you can look at the tree.
See Visualizations.
1404 problems, ready to generate
The catalog covers the collections that matter (Grind 75, Blind 75,
NeetCode 150, NeetCode 250, and Algo Master 75) as JSON templates that
generate identical files on every machine. Browse everything in the
Catalog, then lcpy gen -t <collection> and practice.
Extensible by design
- Template-driven: every problem comes from a JSON template plus a
cookiecutter scaffold, so the tree stays consistent and reproducible.
See Problem Creation.
- LLM-assisted creation: the repo ships command specs that let Claude
Code, Cursor, or Copilot add new problems and strengthen test suites
following the house rules. See
LLM-Assisted Problem Creation.
- Production hygiene: type hints everywhere, loguru-powered test logs,
95%+ coverage, security scanning, and CI that verifies problems regenerate
byte-identically from their templates.
The loop
Generate, read the README, implement solution.py, run pytest, inspect in
playground, next problem. Every problem, the same shape. That consistency
is the feature: nothing between you and the algorithm except the algorithm.
The terminal side of the loop is walked through in
Test LeetCode Solutions Locally. Last modified on September 3, 2026
