问题
I occasionally have Python programs that take a long time to run, and that I want to be able to save the state of and resume later. Does anyone have a clever way of saving the state either every x seconds, or when the program is exiting?
回答1:
Put all of your "state" data in one place and use a pickle.
The pickle module implements a fundamental, but powerful algorithm for serializing and de-serializing a Python object structure. “Pickling” is the process whereby a Python object hierarchy is converted into a byte stream, and “unpickling” is the inverse operation, whereby a byte stream is converted back into an object hierarchy. Pickling (and unpickling) is alternatively known as “serialization”, “marshalling,” 1 or “flattening”, however, to avoid confusion, the terms used here are “pickling” and “unpickling”.
回答2:
If you want to save everything, including the entire namespace and the line of code currently executing to be restarted at any time, there is not a standard library module to do that.
As another poster said, the pickle module can save pretty much everything into a file and then load it again, but you would have to specifically design your program around the pickle module (i.e. saving your "state" -- including variables, etc -- in a class).
回答3:
If you ok with OOP, consider creating a method for each class that output a serialised version ( using pickle ) to file. Then add a second method to load in the instance the data, and if the pickled file is there you call the load method instead of the processing one. I use this approach for ML and it really seed up my workflow.
回答4:
In the traditional programming approach the obvious way to save a state of variables or objects after some point of execution is serialization.
So if you want to execute the program after some heavy already computed state we need to start only from the deserialization part.
These steps will be mostly needed mostly in data science modelling where we load a huge CSV or some other data and compute it and we do not want to recompute every time we run a program.
http://jupyter.org/ - A tool which does these serialization/deserialization automatically without you doing any manual work.
All you need to do is do execute a selected portion of your python code let us say line 10-15, which are dependent on pervious lines 1-9. Jupyter saves the state of 1-9 for you. Explore a tutorial it and give it a try.
来源：https://stackoverflow.com/questions/5568904/saving-the-state-of-a-program-to-allow-it-to-be-resumed