Joblib UserWarning while trying to cache results

Joblib UserWarning while trying to cache results here is the suggestion Joblib is a library used for caching and parallelizing Python functions. When using Joblib to cache the results of a function, you may encounter a UserWarning that says something like:

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UserWarning: Loky-backed parallel loops cannot be called in multiprocessing, setting n_jobs=1

This warning occurs because Joblib's default parallel backend is based on the Loky library, which uses a multiprocessing-based approach to parallelism. However, when using Joblib to cache results in a multiprocessing environment, the Loky-based backend may cause issues, as multiprocessing is already being used.

To resolve this warning, you can set the n_jobs parameter to 1 when creating the Memory object or when calling the cached function, like so:

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from joblib import Memory, cached

memory = Memory(location='cache_dir', verbose=0)

cached_func = cached(memory.cache(func), n_jobs=1)

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By setting n_jobs to 1, you will force Joblib to use a single-threaded approach to parallelism, which should avoid the warning.