Prediction Deep Copy / Replace

[mawelborn]

A small "Zen of Python" enhancement for using idiomatic copy.deepcopy() and copy.replace() functions with correct and performant behavior.

I previously implemented Prediction.copy() because copy.deepcopy(prediction) copied immutable objects, which is unnecessary and particularly expensive when OCR is assigned. (Copying the whole associated table, its cells, and all their tokens for each prediction copy is slow, to no one's surprise.)

I've since learned the behaviour of copy.deepcopy() can be customized by implementing __deepcopy__() on classes. This PR drops Prediction.copy() in favor of the idiomatic copy.deepcopy(), customizing the latter's behavior to not copy immutable objects, thus getting the same speed and memory improvements as the custom Prediction.copy() implementation.

This PR also adds support for the Python 3.13+ copy.replace() function via __replace__(). It has better ergonomics than dataclasses.replace() by performing a deep copy as above and additionally supports assignment of computed class properties.

Where before:

new_prediction = dataclasses.replace(
    prediction.copy(),  # Must remember to copy to avoid shared mutable state.
    label="EXCEPTION_FLAG",
    confidence=1.0,  # Computed property not supported by `replace()`.
    span=etl_output.tokens[0].span,  # Same here and for other properties.
)

Now:

new_prediction = copy.replace(
    prediction,  # Mutable state handled for you.
    label="EXCEPTION_FLAG",
    confidence=1.0,  # Computed properties can be updated like attributes.
    span=etl_output.tokens[0].span,
)

---

Note

Introduces idiomatic, performant copying for predictions and results.

• Add optimized __deepcopy__ to Prediction and subclasses (DocumentExtraction, Summarization, Unbundling) to avoid copying immutable/large OCR objects; implement Result.__deepcopy__ (deep-copies predictions only)
• Replace custom copy() implementations with standard copy.deepcopy(); remove dataclasses.replace-based copies
• Implement Python 3.13+ copy.replace() via Prediction.__replace__, and unshadow it in subclasses (del <Subclass>.__replace__)
• Minor import cleanups aligned with the new copy strategy

^{Written by Cursor Bugbot for commit af42845. This will update automatically on new commits. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with Cloud Agents, enable Autofix in the Cursor dashboard.}

[cursor]

AttributeError on Python < 3.13 from del replace

High Severity

The del ClassName.__replace__ statements (in classification.py, extraction.py, documentextraction.py, formextraction.py, summarization.py, and unbundling.py) will raise AttributeError on Python 3.10–3.12 because @dataclass only generates __replace__ starting in Python 3.13. Since the project specifies requires-python = ">=3.10" in pyproject.toml, these import-time deletions will crash on all supported Python versions except 3.13+.

Additional Locations (2)

• indico_toolkit/results/predictions/extraction.py#L38-L39
• indico_toolkit/results/predictions/documentextraction.py#L208-L209