如何节约内存：
一个问题：
TerminatedWorkerError: A worker process managed by the executor was unexpectedly terminated. This could be caused by a segmentation fault while calling the function or by an excessive memory usage causing the Operating System to kill the worker.
其实导致问题的主要原因就是内存不够，限制一下n_jobs的数目
参考文献：
机器学习优化器Optimizer的总结TerminatedWorkerError: A worker process managed by the executor was unexpectedly terminatedGridSearchCV - How to limit memory usage
