---
id: listcrunch
version: "1.0.1"
license: unclear
license_treatment: permissive
maintenance: abandoned
---

# listcrunch — A simple human-readable way to compress redundant sequential data

License: permissive · Maintenance: abandoned · Downloads: 257.8K/mo

## What it is and what it does

ListCrunch is a lightweight data compression utility that encodes sequences of repeated values into a compact, human-readable string format. Instead of storing `[1, 1, 1, 1, 1, 1, 1, 1, 1, 2]`, it produces `'1:0-8;2:9'`, indicating that value 1 occupies indices 0 through 8 and value 2 is at index 9. The package provides two main functions: `crunch()` to compress and `uncrunch()` to decompress.

With zero runtime dependencies and a pure-Python implementation, it installs with no friction. However, the project has not been maintained since 2020-06-15, meaning no bug fixes, security patches, or feature updates have been released in over 2251 days. The codebase is still available and the MIT license is permissive, but users should treat it as a stable snapshot rather than an actively supported tool.

Use it for:

- Compress log files or sensor data where consecutive readings are identical to reduce storage footprint.
- Encode sparse arrays or sequences with long runs of the same value for efficient transmission.
- Store game state or animation frame data where many frames repeat the same values.
- Deduplicate time-series data before archival or analysis.
- Create human-inspectable representations of repetitive sequences for debugging or documentation.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Compresses sequences of repeated values into a human-readable format and decompresses them back to their original form.

Yes, if you need simple run-length encoding with no external dependencies and can accept an unmaintained codebase. The permissive MIT license, low install friction, and zero security vulnerabilities make it safe to use in isolation. However, do not rely on it for mission-critical systems or expect updates—treat it as a stable utility for specific compression tasks where the format suits your data.

## Install

pip install listcrunch
uv add listcrunch
poetry add listcrunch

## Installing listcrunch

Before you install: No runtime dependencies and a pure-Python wheel make installation straightforward, but the package has been abandoned since 2020-06-15 with no maintenance activity for over 2251 days.

License in practice: MIT license permits commercial and private use with minimal restrictions, requiring only that you retain the license notice.

Quickstart:

from listcrunch import crunch, uncrunch

compressed = crunch([1, 1, 1, 1, 1, 1, 1, 1, 1, 2])
# Returns '1:0-8;2:9'

original = uncrunch('50:0-1,3-4;3:2,5;60:6;70:7-8')
# Returns ['50', '50', '3', '50', '50', '3', '60', '70', '70']

Verify before relying:

- Whether the compression format remains stable and suitable for long-term data storage
- Performance characteristics on large datasets or deeply nested sequences
- Compatibility with Python versions beyond 2 and 3 (classifiers list both but requires_python is unspecified)

## Package facts

- License: not declared (permissive)
- Python support: unspecified
- Install friction: low
- Maintenance: abandoned
- Downloads: 257.8K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

compress repeated data, run-length encoding, sequence compression, data deduplication, compact sequential values, human-readable compression, compression, data-encoding, unmaintained

[View on SkillFed](https://skillfed.io/packages/listcrunch) · [View on PyPI](https://pypi.org/project/listcrunch/)