---
id: heapdict
version: "1.0.1"
license: BSD
license_treatment: permissive
maintenance: abandoned
---

# HeapDict — a heap with decrease-key and increase-key operations

License: permissive · Maintenance: abandoned · Downloads: 412.6K/mo

## What it is and what it does

HeapDict implements a priority queue as a mutable mapping—it behaves like a Python dict but maintains heap ordering. You assign priorities to keys and retrieve the lowest-priority item with popitem(), or peek at it without removal using peekitem(). Unlike the standard library's heapq, HeapDict lets you efficiently update an existing key's priority, which is essential for graph algorithms like Dijkstra's shortest path and A* search.

The package has no runtime dependencies and installs cleanly as a pure Python wheel. It is marked abandoned, with the last release in 2019-09-09 and no active repository maintenance, so it receives no updates or bug fixes. The BSD license is permissive and poses no restrictions for most use cases.

Use it for:

- Implementing Dijkstra's shortest-path algorithm where you need to update node priorities as better paths are discovered.
- Building an A* pathfinding search where heuristic estimates require efficient priority adjustment during exploration.
- Any graph or optimization algorithm that maintains a working set of candidates with changing priority scores.
- Prototyping or teaching priority queue concepts when you need dict-like access with heap semantics.

## Worth the install?

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

HeapDict is a mutable mapping that acts as a priority queue, supporting efficient priority updates on existing keys—a capability the standard library's heapq module lacks.

Yes, if you need a priority queue with efficient decrease-key operations and can accept that the package is no longer maintained. It has no dependencies, installs easily, carries no known vulnerabilities, and solves a real problem the standard library doesn't address. However, verify it works on your target Python version and consider whether an actively maintained alternative better suits your long-term needs.

## Install

pip install heapdict
uv add heapdict
poetry add heapdict

## Installing HeapDict

Before you install: Installation is straightforward with no runtime dependencies. The package is marked abandoned (last release 2019-09-09, 2531 days ago), so expect no active maintenance or bug fixes.

License in practice: Licensed under BSD (permissive), so you may use, modify, and distribute it freely in both open and closed projects with minimal restrictions.

Quickstart:

from heapdict import heapdict

hd = heapdict()
hd['obj1'] = 1
hd['obj2'] = 2
key, priority = hd.popitem()

Verify before relying:

- Whether the package works reliably on modern Python versions beyond those listed in classifiers.
- Performance characteristics compared to alternative priority queue implementations for large datasets.
- Whether any edge cases or bugs have been discovered since the final 2019-09-09 release.

## Package facts

- License: BSD (permissive)
- Python support: unspecified
- Install friction: low
- Maintenance: abandoned
- Downloads: 412.6K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

priority queue with decrease-key, mutable heap dictionary, dijkstra algorithm priority queue, efficient priority update heap, a* search priority queue, heap with key modification, changeable priority queue, priority-queue, graph-algorithms, abandoned-but-stable

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