I am following the book and lecture 2 fastai (2022) on the grizzly bear chapter…all the cells are working except when I put the code and attempt to run:
dls = bears.dataloaders(path)
I get this error message:
TypeError Traceback (most recent call last)
/tmp/ipykernel_27/3866548988.py in
----> 1 dls = bears.dataloaders(path)
/opt/conda/lib/python3.7/site-packages/fastai/data/block.py in dataloaders(self, source, path, verbose, **kwargs)
153 **kwargs
154 ) → DataLoaders:
→ 155 dsets = self.datasets(source, verbose=verbose)
156 kwargs = {**self.dls_kwargs, **kwargs, ‘verbose’: verbose}
157 return dsets.dataloaders(path=path, after_item=self.item_tfms, after_batch=self.batch_tfms, **kwargs)
/opt/conda/lib/python3.7/site-packages/fastai/data/block.py in datasets(self, source, verbose)
145 splits = (self.splitter or RandomSplitter())(items)
146 pv(f"{len(splits)} datasets of sizes {‘,’.join([str(len(s)) for s in splits])}", verbose)
→ 147 return Datasets(items, tfms=self._combine_type_tfms(), splits=splits, dl_type=self.dl_type, n_inp=self.n_inp, verbose=verbose)
148
149 def dataloaders(self,
/opt/conda/lib/python3.7/site-packages/fastai/data/core.py in init(self, items, tfms, tls, n_inp, dl_type, **kwargs)
452 ):
453 super().init(dl_type=dl_type)
→ 454 self.tls = L(tls if tls else [TfmdLists(items, t, **kwargs) for t in L(ifnone(tfms,[None]))])
455 self.n_inp = ifnone(n_inp, max(1, len(self.tls)-1))
456
/opt/conda/lib/python3.7/site-packages/fastai/data/core.py in (.0)
452 ):
453 super().init(dl_type=dl_type)
→ 454 self.tls = L(tls if tls else [TfmdLists(items, t, **kwargs) for t in L(ifnone(tfms,[None]))])
455 self.n_inp = ifnone(n_inp, max(1, len(self.tls)-1))
456
/opt/conda/lib/python3.7/site-packages/fastcore/foundation.py in call(cls, x, *args, **kwargs)
96 def call(cls, x=None, *args, **kwargs):
97 if not args and not kwargs and x is not None and isinstance(x,cls): return x
—> 98 return super().call(x, *args, **kwargs)
99
100 # %% …/nbs/02_foundation.ipynb 46
/opt/conda/lib/python3.7/site-packages/fastai/data/core.py in init(self, items, tfms, use_list, do_setup, split_idx, train_setup, splits, types, verbose, dl_type)
366 if do_setup:
367 pv(f"Setting up {self.tfms}", verbose)
→ 368 self.setup(train_setup=train_setup)
369
370 def _new(self, items, split_idx=None, **kwargs):
/opt/conda/lib/python3.7/site-packages/fastai/data/core.py in setup(self, train_setup)
395 x = f(x)
396 self.types.append(type(x))
→ 397 types = L(t if is_listy(t) else [t] for t in self.types).concat().unique()
398 self.pretty_types = ‘\n’.join([f’ - {t}’ for t in types])
399
TypeError: ‘NoneType’ object is not iterable
