dill.load_session Fails

[Denis]

I tried to save and load session using dill.

import dill
dill.dump_session('stage1.db')

restart computer

import dill
dill.load_session('stage1.db')

but it gives me an error

TypeError                                 Traceback (most recent call last)
Cell In[1], line 2
      1 import dill
----> 2 dill.load_session('stage1.db')

File [c:\Users\justw\miniconda3\envs\dsenv\lib\site-packages\dill\session.py:489](file:///C:/Users/justw/miniconda3/envs/dsenv/lib/site-packages/dill/session.py:489), in load_session(filename, main, **kwds)
    487 def load_session(filename=str(TEMPDIR/'session.pkl'), main=None, **kwds):
    488     warnings.warn("load_session() has been renamed load_module().", PendingDeprecationWarning)
--> 489     load_module(filename, module=main, **kwds)

File [c:\Users\justw\miniconda3\envs\dsenv\lib\site-packages\dill\session.py:471](file:///C:/Users/justw/miniconda3/envs/dsenv/lib/site-packages/dill/session.py:471), in load_module(filename, module, **kwds)
    468         runtime_main = '__runtime__.%s' % main.__name__
    469         sys.modules[runtime_main] = main
--> 471     loaded = unpickler.load()
    472 finally:
    473     if not hasattr(filename, 'read'):  # if newly opened file

File [c:\Users\justw\miniconda3\envs\dsenv\lib\site-packages\dill\_dill.py:419](file:///C:/Users/justw/miniconda3/envs/dsenv/lib/site-packages/dill/_dill.py:419), in Unpickler.load(self)
    418 def load(self): #NOTE: if settings change, need to update attributes
--> 419     obj = StockUnpickler.load(self)
    420     if type(obj).__module__ == getattr(_main_module, '__name__', '__main__'):
    421         if not self._ignore:
    422             # point obj class to main

TypeError: Template.__new__() missing 1 required positional argument: 'source'

dill vesrion is 0.3.6
Python 3.10.11
Windows

[Mike McKerns]

I'm not getting the same thing as you (however, I'm testing on a Mac):

Python 3.10.11 (main, Apr  8 2023, 00:55:46) [Clang 10.0.1 (clang-1001.0.46.4)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import dill
>>> dill.__version__
'0.3.6'
>>> foo = lambda x:x*x
>>> bar = 4
>>> dill.dump_session('stage1.db')
>>> 
dude>$ python
Python 3.10.11 (main, Apr  8 2023, 00:55:46) [Clang 10.0.1 (clang-1001.0.46.4)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import dill
>>> dill.load_session('stage1.db')
>>> foo(bar)
16
>>> 

Are you seeing the same error in all cases, or is there something in particular that triggers the error? If so, please provide a minimal test case the reproduces what you are seeing.

From the traceback, it seems like some object pickled, but failed to load.

[Denis]

Hm.
I have tried your example and it did work.
In my case there is a big jupyter notebook, so I will try to get the smallest example when it fails and post it here.

[Mike McKerns]

This confirms that you have an unpickleable object in your notebook, or more specifically, an object that fails upon deserialization (e.g. load).

[Denis]

Is there a way to make some kind of verbose load_session, so I can understand what object fails?