Ethan Welty <ethan.we...@gmail.com> added the comment: Terry Reedy: I just tried your suggestion of a main clause (code below) and it made no difference.
``` import _tkinter import numpy as np # multiprocessing.set_start_method("spawn") import multiprocessing def parallel_matmul(x): R = np.random.randn(3, 3) return np.matmul(R, x) if __name__ == '__main__': pool = multiprocessing.Pool(4) results = pool.map(parallel_matmul, [np.random.randn(3, 5000) for i in range(2)]) ``` Ronald Oussoren: Good to know that perhaps upgrading to the latest OSX would resolve this issue. I tried 'spawn' and 'forkserver' with multiprocessing.set_start_method() (see above) but both result in an endless stream of errors (with or without importing a graphics backend), although that may be my not knowing how to properly use them. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue33111> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com