Fix: Defer TableWidget import to prevent ZMQ port conflicts #2309
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| __all__ = ["TableWidget"] | ||
| except Exception: | ||
| pass | ||
| def __getattr__(name: str) -> Any: |
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This isn't typical to do, so could you please add some comments explaining why we defer in this way in the docstring and/or comments as well?
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Thanks for suggestion. I add docstring.
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This PR addresses a flaky ZMQError: Address already in use that occasionally occurred during parallel notebook test execution.
Problem:
The bigframes.display module eagerly imported anywidget and traitlets at module load time (
bigframes/display/__init__.py). This meant that when multiple Jupyter kernels were spun up simultaneously by nox for parallel testing, they would all try to initialize traitlets.HasTraits objects with sync=True properties. This led to race conditions and ZMQ port conflicts, causing notebook tests (including those that did not directly use anywidget likestreaming_dataframe.ipynb) to fail. Log is here.Solution:
The TableWidget class import in
bigframes/display/__init__.pyhas been refactored to use Python's__getattr__for lazy loading. This ensures that anywidget and traitlets are only imported and their associated kernel communication channels are initialized when display.TableWidget is actually accessed by the code. This prevents premature initialization and eliminates the port collision race condition during parallel test startup.Fixes #<465768150> 🦕