In [1]: import dataclasses as dc In [2]: import typing as ty In [3]: import cloudpickle as cp In [4]: @dc.dataclass ...: class A: ...: a: ty.Optional[int]=None ...: In [5]: cp.dumps(A) ---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-5-63d18a4a1006> in <module>
----> 1 cp.dumps(A)
/software/miniconda3/envs/pydra-dev/lib/python3.7/site-packages/cloudpickle/cloudpickle.py in dumps(obj, protocol)
929 try:
930 cp = CloudPickler(file, protocol=protocol)
--> 931 cp.dump(obj)
932 return file.getvalue()
933 finally:
/software/miniconda3/envs/pydra-dev/lib/python3.7/site-packages/cloudpickle/cloudpickle.py in dump(self, obj)
282 self.inject_addons()
283 try:
--> 284 return Pickler.dump(self, obj)
285 except RuntimeError as e:
286 if 'recursion' in e.args[0]:
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in dump(self, obj)
435 if self.proto >= 4:
436 self.framer.start_framing()
--> 437 self.save(obj)
438 self.write(STOP)
439 self.framer.end_framing()
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save(self, obj, save_persistent_id)
502 f = self.dispatch.get(t)
503 if f is not None:
--> 504 f(self, obj) # Call unbound method with explicit self
505 return
506 /software/miniconda3/envs/pydra-dev/lib/python3.7/site-packages/cloudpickle/cloudpickle.py in save_global(self, obj, name, pack)
676 677 if obj.__module__ == "__main__":
--> 678 return self.save_dynamic_class(obj)
679 680 try:
/software/miniconda3/envs/pydra-dev/lib/python3.7/site-packages/cloudpickle/cloudpickle.py in save_dynamic_class(self, obj)
515 # Now save the rest of obj's __dict__. Any references to obj
516 # encountered while saving will point to the skeleton class.
--> 517 save(clsdict)
518 519 # Write a tuple of (skeleton_class, clsdict).
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save(self, obj, save_persistent_id)
502 f = self.dispatch.get(t)
503 if f is not None:
--> 504 f(self, obj) # Call unbound method with explicit self
505 return
506 /software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save_dict(self, obj)
854 855 self.memoize(obj)
--> 856 self._batch_setitems(obj.items())
857 858 dispatch[dict] = save_dict
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in _batch_setitems(self, items)
880 for k, v in tmp:
881 save(k)
--> 882 save(v)
883 write(SETITEMS)
884 elif n:
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save(self, obj, save_persistent_id)
502 f = self.dispatch.get(t)
503 if f is not None:
--> 504 f(self, obj) # Call unbound method with explicit self
505 return
506 /software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save_dict(self, obj)
854 855 self.memoize(obj)
--> 856 self._batch_setitems(obj.items())
857 858 dispatch[dict] = save_dict
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in _batch_setitems(self, items)
885 k, v = tmp[0]
886 save(k)
--> 887 save(v)
888 write(SETITEM)
889 # else tmp is empty, and we're done
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save(self, obj, save_persistent_id)
547 548 # Save the reduce() output and finally memoize the object
--> 549 self.save_reduce(obj=obj, *rv)
550 551 def persistent_id(self, obj):
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save_reduce(self, func, args, state, listitems, dictitems, obj)
660 661 if state is not None:
--> 662 save(state)
663 write(BUILD)
664 /software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save(self, obj, save_persistent_id)
502 f = self.dispatch.get(t)
503 if f is not None:
--> 504 f(self, obj) # Call unbound method with explicit self
505 return
506 /software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save_tuple(self, obj)
769 if n <= 3 and self.proto >= 2:
770 for element in obj:
--> 771 save(element)
772 # Subtle. Same as in the big comment below.
773 if id(obj) in memo:
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save(self, obj, save_persistent_id)
502 f = self.dispatch.get(t)
503 if f is not None:
--> 504 f(self, obj) # Call unbound method with explicit self
505 return
506 /software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save_dict(self, obj)
854 855 self.memoize(obj)
--> 856 self._batch_setitems(obj.items())
857 858 dispatch[dict] = save_dict
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in _batch_setitems(self, items)
880 for k, v in tmp:
881 save(k)
--> 882 save(v)
883 write(SETITEMS)
884 elif n:
/software/miniconda3/envs/pydra-dev/lib/python3.7/pickle.py in save(self, obj, save_persistent_id)
522 reduce = getattr(obj, "__reduce_ex__", None)
523 if reduce is not None:
--> 524 rv = reduce(self.proto)
525 else:
526 reduce = getattr(obj, "__reduce__", None)
TypeError: can't pickle mappingproxy objects
cloudpickle appears to still have an issue (see #193, #209) with pickling type annotations. the reason i can't use pickle is that it doesn't support dynamic dataclasses (see: https://bugs.python.org/issue35510), which cloudpickle does support.