polars.thread_pool_size() int[source]#

Return the number of threads in the Polars thread pool.


The thread pool size can be overridden by setting the POLARS_MAX_THREADS environment variable before process start. The thread pool is not behind a lock, so it cannot be modified once set. A reasonable use case for this might be temporarily limiting the number of threads before importing Polars in a PySpark UDF or similar context. Otherwise, it is strongly recommended not to override this value as it will be set automatically by the engine.


>>> pl.thread_pool_size()