学习pytorch基础之图像分类器代码报错解决方案：RuntimeError: An attempt has been made to start a new process before...

图像分类器练习作为学习pytorch基础中的一课，生动给大家展示了如何将多组图片分成多个种类。原教程可以参照链接：https://github.com/fendouai/PyTorchDocs/blob/master/SecondSection/training_a_classifier.md

但是pytorch在训练的过程中，可能会出现一种报错：

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

解决方案是：
（1）加main函数，在main函数中调用 。（我尝试了这一种）
（2）num_workers改为0，单进程加载。

以上改动的具体方案及代码，请大家参考原文：https://blog.csdn.net/yaoyutian/article/details/85086129
https://blog.csdn.net/jacke121/article/details/81456842

在此感谢以上博主的优秀方案！