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Python multiprocessing: Pickling Errors, Lambdas, Local Functions That Hang Pool.map, spawn vs fork and Shared State

By ThisIsDave — Dave Saylor

Executed on Python 3.10: default start method fork, spawn pools with module functions, PicklingError for lambdas, AttributeError for local objects, a local function hanging map until map_async timeout, locks not picklable, shared Value counters and lost list appends.