dill.dump_session 在 jupyter 实验室中不起作用答案

【问题标题】：dill.dump_session won't work in jupyter labdill.dump_session 在 jupyter 实验室中不起作用
【发布时间】：2020-02-10 12:20:38
【问题描述】：

我想开始使用 jupyter lab 而不是 spyder，但我遇到了问题。我无法将变量保存在我的工作区中。

我正在尝试使用 jupyter lab 来运行这样的代码：

import dill
import pandas as pd
import numpy as np

df = pd.DataFrame({'A': np.arange(1,300), 'B': np.arange(2,301)})
STRIN = 'A'
aa = 34

dill.dump_session('filename.p')

我收到以下错误：

TypeError: no default __reduce__ due to non-trivial __cinit__

完整的追溯是：

TypeError                                 Traceback (most recent call last)
<ipython-input-12-613d82353bf4> in <module>
----> 1 dill.dump_session('filename.p')

~\Anaconda3\lib\site-packages\dill\_dill.py in dump_session(filename, main, byref, **kwds)
    349         pickler._recurse = False # disable pickling recursion for globals
    350         pickler._session = True  # is best indicator of when pickling a session
--> 351         pickler.dump(main)
    352     finally:
    353         if f is not filename:  # If newly opened file

~\Anaconda3\lib\site-packages\dill\_dill.py in dump(self, obj)
    443             raise PicklingError(msg)
    444         else:
--> 445             StockPickler.dump(self, obj)
    446         stack.clear()  # clear record of 'recursion-sensitive' pickled objects
    447         return

~\Anaconda3\lib\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()

~\Anaconda3\lib\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 

~\Anaconda3\lib\site-packages\dill\_dill.py in save_module(pickler, obj)
   1293                 + ["__builtins__", "__loader__"]]
   1294             pickler.save_reduce(_import_module, (obj.__name__,), obj=obj,
-> 1295                                 state=_main_dict)
   1296             log.info("# M1")
   1297         else:

~\Anaconda3\lib\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 

~\Anaconda3\lib\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 

~\Anaconda3\lib\site-packages\dill\_dill.py in save_module_dict(pickler, obj)
    910             # we only care about session the first pass thru
    911             pickler._session = False
--> 912         StockPickler.save_dict(pickler, obj)
    913         log.info("# D2")
    914     return

~\Anaconda3\lib\pickle.py in save_dict(self, obj)
    857 
    858         self.memoize(obj)
--> 859         self._batch_setitems(obj.items())
    860 
    861     dispatch[dict] = save_dict

~\Anaconda3\lib\pickle.py in _batch_setitems(self, items)
    883                 for k, v in tmp:
    884                     save(k)
--> 885                     save(v)
    886                 write(SETITEMS)
    887             elif n:

~\Anaconda3\lib\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):

~\Anaconda3\lib\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 

~\Anaconda3\lib\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 

~\Anaconda3\lib\site-packages\dill\_dill.py in save_module_dict(pickler, obj)
    910             # we only care about session the first pass thru
    911             pickler._session = False
--> 912         StockPickler.save_dict(pickler, obj)
    913         log.info("# D2")
    914     return

~\Anaconda3\lib\pickle.py in save_dict(self, obj)
    857 
    858         self.memoize(obj)
--> 859         self._batch_setitems(obj.items())
    860 
    861     dispatch[dict] = save_dict

~\Anaconda3\lib\pickle.py in _batch_setitems(self, items)
    883                 for k, v in tmp:
    884                     save(k)
--> 885                     save(v)
    886                 write(SETITEMS)
    887             elif n:

~\Anaconda3\lib\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):

~\Anaconda3\lib\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 

~\Anaconda3\lib\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 

~\Anaconda3\lib\site-packages\dill\_dill.py in save_module_dict(pickler, obj)
    910             # we only care about session the first pass thru
    911             pickler._session = False
--> 912         StockPickler.save_dict(pickler, obj)
    913         log.info("# D2")
    914     return

~\Anaconda3\lib\pickle.py in save_dict(self, obj)
    857 
    858         self.memoize(obj)
--> 859         self._batch_setitems(obj.items())
    860 
    861     dispatch[dict] = save_dict

~\Anaconda3\lib\pickle.py in _batch_setitems(self, items)
    883                 for k, v in tmp:
    884                     save(k)
--> 885                     save(v)
    886                 write(SETITEMS)
    887             elif n:

~\Anaconda3\lib\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 

~\Anaconda3\lib\site-packages\dill\_dill.py in save_module_dict(pickler, obj)
    910             # we only care about session the first pass thru
    911             pickler._session = False
--> 912         StockPickler.save_dict(pickler, obj)
    913         log.info("# D2")
    914     return

~\Anaconda3\lib\pickle.py in save_dict(self, obj)
    857 
    858         self.memoize(obj)
--> 859         self._batch_setitems(obj.items())
    860 
    861     dispatch[dict] = save_dict

~\Anaconda3\lib\pickle.py in _batch_setitems(self, items)
    883                 for k, v in tmp:
    884                     save(k)
--> 885                     save(v)
    886                 write(SETITEMS)
    887             elif n:

~\Anaconda3\lib\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):

~\Anaconda3\lib\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 

~\Anaconda3\lib\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 

~\Anaconda3\lib\site-packages\dill\_dill.py in save_module_dict(pickler, obj)
    910             # we only care about session the first pass thru
    911             pickler._session = False
--> 912         StockPickler.save_dict(pickler, obj)
    913         log.info("# D2")
    914     return

~\Anaconda3\lib\pickle.py in save_dict(self, obj)
    857 
    858         self.memoize(obj)
--> 859         self._batch_setitems(obj.items())
    860 
    861     dispatch[dict] = save_dict

~\Anaconda3\lib\pickle.py in _batch_setitems(self, items)
    883                 for k, v in tmp:
    884                     save(k)
--> 885                     save(v)
    886                 write(SETITEMS)
    887             elif n:

~\Anaconda3\lib\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 

~\Anaconda3\lib\site-packages\dill\_dill.py in save_module_dict(pickler, obj)
    910             # we only care about session the first pass thru
    911             pickler._session = False
--> 912         StockPickler.save_dict(pickler, obj)
    913         log.info("# D2")
    914     return

~\Anaconda3\lib\pickle.py in save_dict(self, obj)
    857 
    858         self.memoize(obj)
--> 859         self._batch_setitems(obj.items())
    860 
    861     dispatch[dict] = save_dict

~\Anaconda3\lib\pickle.py in _batch_setitems(self, items)
    883                 for k, v in tmp:
    884                     save(k)
--> 885                     save(v)
    886                 write(SETITEMS)
    887             elif n:

~\Anaconda3\lib\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):

~\Anaconda3\lib\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 

~\Anaconda3\lib\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 

~\Anaconda3\lib\site-packages\dill\_dill.py in save_module_dict(pickler, obj)
    910             # we only care about session the first pass thru
    911             pickler._session = False
--> 912         StockPickler.save_dict(pickler, obj)
    913         log.info("# D2")
    914     return

~\Anaconda3\lib\pickle.py in save_dict(self, obj)
    857 
    858         self.memoize(obj)
--> 859         self._batch_setitems(obj.items())
    860 
    861     dispatch[dict] = save_dict

~\Anaconda3\lib\pickle.py in _batch_setitems(self, items)
    888                 k, v = tmp[0]
    889                 save(k)
--> 890                 save(v)
    891                 write(SETITEM)
    892             # else tmp is empty, and we're done

~\Anaconda3\lib\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):

~\Anaconda3\lib\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 

~\Anaconda3\lib\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 

~\Anaconda3\lib\site-packages\dill\_dill.py in save_module_dict(pickler, obj)
    910             # we only care about session the first pass thru
    911             pickler._session = False
--> 912         StockPickler.save_dict(pickler, obj)
    913         log.info("# D2")
    914     return

~\Anaconda3\lib\pickle.py in save_dict(self, obj)
    857 
    858         self.memoize(obj)
--> 859         self._batch_setitems(obj.items())
    860 
    861     dispatch[dict] = save_dict

~\Anaconda3\lib\pickle.py in _batch_setitems(self, items)
    883                 for k, v in tmp:
    884                     save(k)
--> 885                     save(v)
    886                 write(SETITEMS)
    887             elif n:

~\Anaconda3\lib\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)

~\Anaconda3\lib\site-packages\zmq\backend\cython\socket.cp37-win_amd64.pyd in zmq.backend.cython.socket.Socket.__reduce_cython__()

TypeError: no default __reduce__ due to non-trivial __cinit__

我能做些什么来解决这个问题？

谢谢！

【问题讨论】：

请包含完整的回溯。如果我不得不冒险猜测某些 pandas 类型没有 dill 所期望的 __reduce__ 实现，如果没有完整的回溯，很难确定。如果你真的需要这样做，我怀疑不修补一些你无法控制的下游库是可能的。
如果我只想保存简单的变量，如整数和字符串，它实际上也会发生。我添加了回溯。谢谢。

标签： python cython jupyter-lab dill

【解决方案1】：

看起来 dill 正在尝试腌制一个 zmq 套接字，这是因为 jupyter 环境挂钩到您的会话中。参见例如https://github.com/uqfoundation/pathos/issues/132#issuecomment-501906583 和 https://github.com/uqfoundation/dill/issues/255。

我敢打赌，如果您尝试在 jupyter 之外执行此操作，它会起作用。

我猜 dill 可能会做更多的事情来检测它正在 jupyter 中运行并避免这种情况，但目前它似乎不是这样工作的。

【讨论】：