belljar 0.1.2

Extremely simple to use callable memoization decorator library.

belljar 🫙

Conditional memoization for complex runtime state.

Standard decorators check the cache before execution. belljar lets you check the cache during execution.

By calling includes(), you update the hash with runtime state (like file handles or database cursors). If belljar detects that this specific state has been processed before, execution stops immediately and the cached result is returned.

Usage

from belljar import jar, includes

@jar
def parse_log(file_handle):
    # 1. State is initially just the function args.
    
    # 2. Add runtime state to the hash (e.g., file cursor position).
    includes(file_handle)

    # CHECKPOINT: 
    # If this exact sequence (args + file state) exists in the cache,
    # execution STOPS here and returns the stored value.
    
    print("Heavy processing...")
    return file_handle.read()

Features

• Mid-Execution Cache Hits: Skip the heavy lifting if the intermediate state is recognized.
• Complex Serialization: Uses dill instead of pickle, supporting lambdas, local classes, and closures.
• Zero Config: caches to .jar/ by default, or pass a path: @jar(Path("/tmp/cache")).

Installation

uv add belljar
# or
pip install belljar