How to debug your code and ask for help with fastai v2

fastai
3

So, I’m trying to follow the tutorial on docs.fast.ai, and I wrote this code:

from fastai.vision.all import *

path = untar_data(URLs.PETS)

files = get_image_files(path/"images")

def label_func(f): return f[0].isupper()

dls = ImageDataLoaders.from_name_func(path, files, label_func, item_tfms=Resize(224), num_workers=0,device=torch.device('cuda'))

learn = vision_learner(dls, resnet34, metrics=error_rate)
learn.fine_tune(2)
learn.export(r'{private}/model.pkl')

But when I try to use load_learner in a interpreter, I get this error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\{private}\miniconda3\envs\fastai\lib\site-packages\fastai\learner.py", line 446, in load_learner
    try: res = torch.load(fname, map_location=map_loc, pickle_module=pickle_module)
  File "C:\Users\{private}\miniconda3\envs\fastai\lib\site-packages\torch\serialization.py", line 789, in load
    return _load(opened_zipfile, map_location, pickle_module, **pickle_load_args)
  File "C:\Users\{private}\miniconda3\envs\fastai\lib\site-packages\torch\serialization.py", line 1131, in _load
    result = unpickler.load()
  File "C:\Users\{private}\miniconda3\envs\fastai\lib\site-packages\torch\serialization.py", line 1124, in find_class
    return super().find_class(mod_name, name)
AttributeError: Custom classes or functions exported with your `Learner` not available in namespace.\Re-declare/import before loading:
        Can't get attribute 'label_func' on <module '__main__' (built-in)>
6 Likes