Overview

plr(python-leetcode-runner) is a tool to fetch LeetCode problems (using the problem title slug) and then to test your solutions.

plr handles the most common custom-judge cases directly from the docstring, so you usually do not need to add extra helper functions to the solution file.

Installation

Use uv to install and manage plr.

uv tool install git+https://github.com/dashmage/plr.git

Usage

From the LeetCode problem URL, obtain the title slug name. For the two sum problem, that would be two-sum.

Now run,

$ plr pull two-sum
# Or even directly with: uv run plr pull two-sum

001-two-sum.py has been created! Happy solving

This fetches the problem description and python starter code and adds into the newly created 001-two-sum.py python file. 001 is the zero-padded problem ID for the two sum problem.

After coding up a solution and adding it to the Solution class, run the plr test command with the path to the problem file to validate it against the example test cases.

$ plr test 001-two-sum.py
# Or: python -m plr test 001-two-sum.py

This will test the Solution class method(s) with the examples automatically parsed from the problem description in the docstring.

Multiple Solutions

You can even provide multiple solution methods in the Solution class and each of them would be validated with the example test cases.

=== twoSum_1 ===

[ OK ]
nums = [2,7,11,15], target = 9
Expected: [0, 1]
Actual  : [0, 1]
------------------------------
[ OK ]
nums = [3,2,4], target = 6
Expected: [1, 2]
Actual  : [1, 2]
------------------------------
[ OK ]
nums = [3,3], target = 6
Expected: [0, 1]
Actual  : [0, 1]
------------------------------

Passed: 3/3

=== twoSum_2 ===

[ FAILED ]
nums = [2,7,11,15], target = 9
Expected: [0, 1]
Actual  : [1, 2, 3]
------------------------------
[ FAILED ]
nums = [3,2,4], target = 6
Expected: [1, 2]
Actual  : [1, 2, 3]
------------------------------
[ FAILED ]
nums = [3,3], target = 6
Expected: [0, 1]
Actual  : [1, 2, 3]
------------------------------

Passed: 0/3

Extra Test Cases

Extra test cases can easily be added by appending a new "Example" in the problem description. This additional test will be picked up by the test validator.

Example 5:
Input: nums = [1,2,3], k = 2
Output: [1,2]

In-Place Array Problems

When the output includes a returned value and a mutated input array, plr treats that as an in-place prefix check automatically.

For example, in Problem #26, duplicates are to be removed from a sorted array. For testing solutions to this problem, we need to evaluate the number of unique elements and return that along with the input array as a tuple.

Here is what a sample input and output look like,

Input: nums = [1,1,2]
Output: 2, nums = [1,2,_]
Explanation: Your function should return k = 2, with the first two elements of nums being 1 and 2 respectively.
It does not matter what you leave beyond the returned k (hence they are underscores).

plr will call the solution, read the returned k, and compare nums[:k] against the non-underscore prefix from the expected output.

Inferred Comparison Rules

For problems where equality is not a simple actual == expected, plr infers the right comparison mode directly from the problem text.

It currently detects:

• order-insensitive flat lists when the problem says the answer can be returned in any order
• order-insensitive nested lists for cases like 3Sum and grouped anagrams
• order-insensitive in-place prefix checks for custom-judge problems such as Remove Element

For example, in Problem #347, the answer can be returned in any order:

Input: nums = [1,1,1,2,2,3], k = 2
Output: [1,2]

For nested outputs such as 3Sum or grouped anagrams:

Input: nums = [-1,0,1,2,-1,-4]
Output: [[-1,-1,2],[-1,0,1]]

For Problem #27, where the first k mutated elements may be in any order:

Input: nums = [3,2,2,3], val = 3
Output: 2, nums = [2,2,_,_]

Take a look at the solved LeetCode problems provided in the repo for concrete examples.

Development

Install the project with the test extra into your local environment.

uv sync --extra test

For a live editable install in a virtualenv:

uv venv
source .venv/bin/activate
uv pip install -e .

This makes the local plr command use your current checkout, so code changes are reflected immediately.

Run the test suite with:

uv run --extra test pytest -q

Run type checking with ty:

ty check

For a one-off local CLI install without activating a venv:

uv tool install --force .