Linear models raise expection at import with dask-2025.1.0

[markotoplak]

Describe the issue:

Since dask==2025.1.0 I get an exception at importing dask_ml.linear_model with the latest dask_ml release (I did not run the development branch but at least the problematic import seems the same here). The same import works with 2024.12.1.

This is probably due to dask_expr inclusion in the main dask distrubution.

I fixed it locally by replacing import dask_expr with from dask.dataframe import dask_expr in linear_model/utils.py.

Minimal Complete Verifiable Example:

$ python -c "import dask_ml.linear_model"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/marko/venv312/lib/python3.12/site-packages/dask_ml/linear_model/__init__.py", line 5, in <module>
    from .glm import LinearRegression, LogisticRegression, PoissonRegression
  File "/home/marko/venv312/lib/python3.12/site-packages/dask_ml/linear_model/glm.py", line 19, in <module>
    from .utils import lr_prob_stack
  File "/home/marko/venv312/lib/python3.12/site-packages/dask_ml/linear_model/utils.py", line 10, in <module>
    import dask_expr
ModuleNotFoundError: No module named 'dask_expr'

[TomAugspurger]

Thanks for the report. Mind making a PR with your fix? IMO, we can bump the minimum supported dask version to 2025.1.0, and avoid the need for compatibility code in dask-ml.

[jrbourbeau]

I was about to open an issue for this but then saw one already existed -- thanks @markotoplak

IMO, we can bump the minimum supported dask version to 2025.1.0, and avoid the need for compatibility code in dask-ml.

+1 -- moving forward with the new default in dask makes sense to me too