RuntimeError: Unexpected optimization level 01. Option are '00' '01' '02' '03'

When I made the following changes to the original code and reported this error, I don’t know where the problem occurred. Can you give me some advice? Thank you. model, optimizer = amp.initialize(model, optimizer, opt_level="O1") with amp.scale_loss(loss, optimizer) as scaled_loss: scaled_loss.backward()

[ptrblck]

Hi @wangyingyu, could you check if you are trying to pass the opt_level as two integers (i.e. “zero one” "01") instead of the expected uppercase O letter and 1 ("O1")?

[thammegowda]

(Glad to find I am not the only one) the names couldn’t get any better than O1, O2, O3 😆! Oh, by the way, that’s not zero😲, it’s the O as in 🍊🤦🏻‍♂️

Suggestion (before moving to pytorch core):

1. consider aliasing to lowercase o at least that would make it obvious when written like o1, o2, o3
2. better yet: please alias them level_1, level_2, level_3 or opt_1, opt_2, opt_3

🙏🏼