context-window-packer-py 0.1.0

Pack context chunks into a budget by relevance and priority. Python port of @mukundakatta/context-window-packer.

context-window-packer-py

Pack context chunks into a budget by relevance and priority. Sort by score (descending), break ties by priority, accept each chunk if it fits, otherwise drop. Zero runtime dependencies.

Python port of @mukundakatta/context-window-packer.

Install

pip install context-window-packer-py

Quick start

from context_window_packer import pack

chunks = [
    {"text": "Pluto was reclassified...", "priority": 1, "relevance": 0.9},
    {"text": "Mars is the fourth planet...", "priority": 0, "relevance": 0.4},
    {"text": "Cats are independent...", "priority": 0, "relevance": 0.1},
]

result = pack(chunks, budget_tokens=20)

result.chunks   # list of dicts that fit
result.tokens   # int -- tokens consumed by kept chunks
result.dropped  # int -- count of chunks not kept

API

pack(chunks, budget_tokens, model=None) -> PackResult

Each chunk is a mapping with at minimum text. Optional fields:

Field	Default	Meaning
text	""	The chunk content.
tokens	ceil(len(text)/4)	Pre-counted tokens (skips estimator).
relevance / score	0	Higher = more relevant; primary sort key (descending).
priority	0	Tie-breaker for relevance (descending).

PackResult is a dataclass with:

• chunks: list[dict] -- chunks that fit, in pack order.
• tokens: int -- total tokens consumed.
• dropped: int -- count of chunks dropped.

model is reserved for future per-family token estimators (currently uses the standard ceil(chars/4) heuristic, matching the JS sibling).

License

MIT