V1 dataloader missing positional arguments

fastai fastai dev
1

Hi,

I am trying to get @radek’s kaggle starter kit to run and I run into an Error that I can’t really understand.

I tried training on GCP and Crestle - all of which are up to date. The weird thing is that I get this bug after training a while. So it runs perfectly fine but after a few batches, training gets interrupted.

I would really appreciate some help!

Thanks!

TypeError                                 Traceback (most recent call last)
<ipython-input-27-390c4543c0c9> in <module>
----> 1 learn.fit_one_cycle(2)

~/anaconda3/envs/fastai-v1/lib/python3.7/site-packages/fastai/train.py in fit_one_cycle(learn, cyc_len, max_lr, moms, div_factor, pct_start, wd, callbacks, **kwargs)
     18     callbacks.append(OneCycleScheduler(learn, max_lr, moms=moms, div_factor=div_factor,
     19                                         pct_start=pct_start, **kwargs))
---> 20     learn.fit(cyc_len, max_lr, wd=wd, callbacks=callbacks)
     21 
     22 def lr_find(learn:Learner, start_lr:Floats=1e-7, end_lr:Floats=10, num_it:int=100, stop_div:bool=True, **kwargs:Any):

~/anaconda3/envs/fastai-v1/lib/python3.7/site-packages/fastai/basic_train.py in fit(self, epochs, lr, wd, callbacks)
    160         callbacks = [cb(self) for cb in self.callback_fns] + listify(callbacks)
    161         fit(epochs, self.model, self.loss_func, opt=self.opt, data=self.data, metrics=self.metrics,
--> 162             callbacks=self.callbacks+callbacks)
    163 
    164     def create_opt(self, lr:Floats, wd:Floats=0.)->None:

~/anaconda3/envs/fastai-v1/lib/python3.7/site-packages/fastai/basic_train.py in fit(epochs, model, loss_func, opt, data, callbacks, metrics)
     92     except Exception as e:
     93         exception = e
---> 94         raise e
     95     finally: cb_handler.on_train_end(exception)
     96 

~/anaconda3/envs/fastai-v1/lib/python3.7/site-packages/fastai/basic_train.py in fit(epochs, model, loss_func, opt, data, callbacks, metrics)
     80             cb_handler.on_epoch_begin()
     81 
---> 82             for xb,yb in progress_bar(data.train_dl, parent=pbar):
     83                 xb, yb = cb_handler.on_batch_begin(xb, yb)
     84                 loss = loss_batch(model, xb, yb, loss_func, opt, cb_handler)

~/anaconda3/envs/fastai-v1/lib/python3.7/site-packages/fastprogress/fastprogress.py in __iter__(self)
     63         self.update(0)
     64         try:
---> 65             for i,o in enumerate(self._gen):
     66                 yield o
     67                 if self.auto_update: self.update(i+1)

~/anaconda3/envs/fastai-v1/lib/python3.7/site-packages/fastai/basic_data.py in __iter__(self)
     45     def __iter__(self):
     46         "Process and returns items from `DataLoader`."
---> 47         for b in self.dl:
     48             y = b[1][0] if is_listy(b[1]) else b[1]
     49             if not self.skip_size1 or y.size(0) != 1:

~/anaconda3/envs/fastai-v1/lib/python3.7/site-packages/torch/utils/data/dataloader.py in __next__(self)
    621         if self.rcvd_idx in self.reorder_dict:
    622             batch = self.reorder_dict.pop(self.rcvd_idx)
--> 623             return self._process_next_batch(batch)
    624 
    625         if self.batches_outstanding == 0:

~/anaconda3/envs/fastai-v1/lib/python3.7/site-packages/torch/utils/data/dataloader.py in _process_next_batch(self, batch)
    656         self._put_indices()
    657         if isinstance(batch, ExceptionWrapper):
--> 658             raise batch.exc_type(batch.exc_msg)
    659         return batch
    660 

TypeError: __init__() missing 2 required positional arguments: 'doc' and 'pos'
2

Had this issue as well, and the underlying cause was malformed JSON data. The error message you are seeing is likely from failing to construct a JSONDecodeError, which requires ‘doc’ and ‘pos’ as positional args in the constructor.

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