错误如下:
RuntimeError:
An attempt has been made to start a new process before the
current process has finished its bootstrapping phase.
This probably means that you are not using fork to start your
child processes and you have forgotten to use the proper idiom
in the main module:
if __name__ == '__main__':
freeze_support()
...
The "freeze_support()" line can be omitted if the program
is not going to be frozen to produce an executable.
ForkingPickler(file, protocol).dump(obj)
BrokenPipeError: [Errno 32] Broken pipe
错误原因:该问题的产生是由于windows下多线程的问题,和DataLoader类有关。将num_workers的数量修改为0即可。这是windows下的一个bug,现在(2020/6/22)仍未解决。