heapmap

heapmap

A thread-safe heap that behaves like a dict but maintains heap ordering.

Features:

• Supports both min-heap and max-heap modes via a simple flag

• Dictionary-style access:

  • h[key] = priority (insert/update)
  • prio = h[key] (lookup)
  • del h[key] (remove)

• Bulk initialization: HeapMap({'a':1, 'b':2})

• Priority operations:

  • h.popitem() & h.peekitem() for root (min or max)
  • h.update(key, new_prio) to change an existing key’s priority

• Introspection:

  • len(h), key in h, h.is_empty()

• Safe iteration:

  • .keys(), .values(), .items(), and plain for k, v in h:
  • Detects concurrent modifications and raises RuntimeError

Installation

pip install heapmap

Quickstart

from heapmap import HeapMap

# Min-heap example
h = HeapMap({'a':5, 'b':2, 'c':3})
print(h.peekitem())  # ('b', 2)

# Insert
h['d'] = 1
print(h.popitem())   # ('d', 1)

# Update
h.update('a', 0)
print(h.peekitem())  # ('a', 0)

# Iterate
for key, prio in h.items():
    print(f"{key} -> {prio}")

API Reference

class HeapMap(MutableMapping):
    def __init__(self, initial=None, is_max_heap=False):
        """Initialize with optional dict and heap mode."""

    def __getitem__(self, key):
        """Get priority for key."""

    def __setitem__(self, key, priority):
        """Insert or update key with priority."""

    def __delitem__(self, key):
        """Remove key from heap."""

    def popitem(self):
        """Remove and return root (min or max) item."""

    def peekitem(self):
        """Return root item without removing it."""

    def update(self, key, new_priority):
        """Change priority and reheapify."""

    def clear(self):
        """Remove all items."""

    def is_empty(self):
        """Return True if heap is empty."""

    def keys(self):
        """Iterator over keys (safe to detect mods)."""

    def values(self):
        """Iterator over priorities."""

    def items(self):
        """Iterator over (key, priority) pairs."""

    def __len__(self):
        """Number of items in heap."""

    def __contains__(self, key):
        """Membership test."""

Testing

pip install -e .[test]  # installs pytest
pytest

Contributing

• Fork the repo
• Create a topic branch
• Submit a PR

License

MIT © Your Name