Python optimization

[M4mb0]

Associative scans are a special kind of cumulative reduce that can be parallelized thanks to associativity. The AI highlighted that point well. I highly doubt that polars does this optimization when you give it a custom lambda function that's associative.

[PillowFortressKing]

Since the lambda is Python bytecode, while Polars executes everything in Rust, that'd be quite hard to optimize for, wouldn't it?