AttributeError: 'tuple' object has no attribute 'log_softmax'

This is a well known problem.

Try one the following solutions:

1. disable aux_logits when the model is created here by also passing aux_logits=False to the inception_v3 function.

2. edit your train function to accept and unpack the returned tuple to be something like: output, aux = model(input_var)

Check the following link for more info.

This problem seams to me like instead you define F:

import torch.nn.functional as F

You in accident have set F to some tuple

F=(1,2)

And then when you call F.log_softmax you get exactly this error.