self.out not initialised properly #118
Description
I'm fitting a model from fastai using jupyter notebook, and it always throws the following exception:
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
Cell In[76], line 1
----> 1 _.fit_one_cycle(1, 0.1)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastai/callback/schedule.py:121, in fit_one_cycle(self, n_epoch, lr_max, div, div_final, pct_start, wd, moms, cbs, reset_opt, start_epoch)
118 lr_max = np.array([h['lr'] for h in self.opt.hypers])
119 scheds = {'lr': combined_cos(pct_start, lr_max[/div](http://localhost:8888/div), lr_max, lr_max[/div_final](http://localhost:8888/div_final)),
120 'mom': combined_cos(pct_start, *(self.moms if moms is None else moms))}
--> 121 self.fit(n_epoch, cbs=ParamScheduler(scheds)+L(cbs), reset_opt=reset_opt, wd=wd, start_epoch=start_epoch)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastai/learner.py:272, in Learner.fit(self, n_epoch, lr, wd, cbs, reset_opt, start_epoch)
270 self.opt.set_hypers(lr=self.lr if lr is None else lr)
271 self.n_epoch = n_epoch
--> 272 self._with_events(self._do_fit, 'fit', CancelFitException, self._end_cleanup)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastai/learner.py:207, in Learner._with_events(self, f, event_type, ex, final)
206 def _with_events(self, f, event_type, ex, final=noop):
--> 207 try: self(f'before_{event_type}'); f()
208 except ex: self(f'after_cancel_{event_type}')
209 self(f'after_{event_type}'); final()
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastai/learner.py:180, in Learner.__call__(self, event_name)
--> 180 def __call__(self, event_name): L(event_name).map(self._call_one)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastcore/foundation.py:225, in curryable.<locals>.wrapper(self, *args, **kwargs)
222 @wraps(f)
223 def wrapper(self, *args, **kwargs):
224 if not isinstance(self, L): return lambda items: f(L(items), self, *args, **kwargs)
--> 225 return f(L(self), *args, **kwargs)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastcore/foundation.py:233, in map(self, f, *args, **kwargs)
229 @patch
230 @curryable
231 def map(self:L, f, *args, **kwargs):
232 "Create new `L` with `f` applied to all `items`, passing `args` and `kwargs` to `f`"
--> 233 return self._new(map_ex(self, f, *args, gen=False, **kwargs))
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastcore/basics.py:952, in map_ex(iterable, f, gen, *args, **kwargs)
950 res = map(g, iterable)
951 if gen: return res
--> 952 return list(res)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastcore/basics.py:937, in bind.__call__(self, *args, **kwargs)
935 if isinstance(v,_Arg): kwargs[k] = args.pop(v.i)
936 fargs = [args[x.i] if isinstance(x, _Arg) else x for x in self.pargs] + args[self.maxi+1:]
--> 937 return self.func(*fargs, **kwargs)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastai/learner.py:184, in Learner._call_one(self, event_name)
182 def _call_one(self, event_name):
183 if not hasattr(event, event_name): raise Exception(f'missing {event_name}')
--> 184 for cb in self.cbs.sorted('order'): cb(event_name)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastai/callback/core.py:64, in Callback.__call__(self, event_name)
62 try: res = getcallable(self, event_name)()
63 except (CancelBatchException, CancelBackwardException, CancelEpochException, CancelFitException, CancelStepException, CancelTrainException, CancelValidException): raise
---> 64 except Exception as e: raise modify_exception(e, f'Exception occured in `{self.__class__.__name__}` when calling event `{event_name}`:\n\t{e.args[0]}', replace=True)
65 if event_name=='after_fit': self.run=True #Reset self.run to True at each end of fit
66 return res
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastai/callback/core.py:62, in Callback.__call__(self, event_name)
60 res = None
61 if self.run and _run:
---> 62 try: res = getcallable(self, event_name)()
63 except (CancelBatchException, CancelBackwardException, CancelEpochException, CancelFitException, CancelStepException, CancelTrainException, CancelValidException): raise
64 except Exception as e: raise modify_exception(e, f'Exception occured in `{self.__class__.__name__}` when calling event `{event_name}`:\n\t{e.args[0]}', replace=True)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastai/callback/progress.py:23, in ProgressCallback.before_fit(self)
21 if self.learn.logger != noop:
22 self.old_logger,self.learn.logger = self.logger,self._write_stats
---> 23 self._write_stats(self.recorder.metric_names)
24 else: self.old_logger = noop
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastai/callback/progress.py:48, in ProgressCallback._write_stats(self, log)
47 def _write_stats(self, log):
---> 48 if getattr(self, 'mbar', False): self.mbar.write([f'{l:.6f}' if isinstance(l, float) else str(l) for l in log], table=True)
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastprogress/fastprogress.py:239, in NBMasterBar.write(self, line, table)
237 if table: self.lines.append(line); self.text_parts = [text2html_table(self.lines)]
238 else: self.text_parts.append(P(line))
--> 239 self.show()
File ~/src/fastai-course/.venv/lib/python3.12/site-packages/fastprogress/fastprogress.py:234, in NBMasterBar.show(self)
231 self.inner_dict['text'] = Div(*self.text_parts)
232 children = [getattr(item, 'progress', None) or item for n in self.order
233 if (item := self.inner_dict.get(n))]
--> 234 self.out.update(Div(*children))
AttributeError: Exception occured in `ProgressCallback` when calling event `before_fit`:
'NBMasterBar' object has no attribute 'out'This can be worked around by disabling the progress bar callback (learn.remove_cb(ProgressCallback)).
Fast.ai before_fit instantiates the progress bar, and then calls show, without ever initialising self.out.
In the code, self.out is initialised in on_iter_begin.
fastprogress version 1.1.3