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Save and retreive multiple dumps() items to/from file

asked 2023-04-04 19:58:44 +0200

brettpim gravatar image

I have written a backtrack search for objects in sagemath. I do not know how many it will find and I would like to write them to a file as I find them with


How can I read them all back in? Something like this solution in python. ​

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answered 2023-04-07 04:02:19 +0200

I'm not sure if this is what you're trying to do:

sage: a = [2/3, 3/4, 5/6]
sage: for x in a:
....:     with open('results', 'wb') as F:
....:         F.write(dumps(a))
sage: with open('results', 'rb') as F:
....:     B = loads(
sage: B
[2/3, 3/4, 5/6]
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answered 2023-04-05 21:03:29 +0200

brettpim gravatar image

updated 2023-04-05 21:22:54 +0200

I tried to use dumps() and loads() to do this in quite a few ways with no luck. I then decided to try it exactly as in the python solution that I link to in the question which works fine. Before the search I open a file for binary writing

f = open("results",'wb')

which is then passed to the search. When I find a solution in the backtrack search I simply call


and then close the file when the search is complete.

To read everything back in I have

f = open("results", "rb")
results = []
        result = pickle.load(f)
except EOFError:
    print("end of file reached")
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If anyone knows how to do this with sagemath's dums() and loads() please add another answer

brettpim gravatar imagebrettpim ( 2023-04-05 22:26:00 +0200 )edit

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Asked: 2023-04-04 19:58:44 +0200

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Last updated: Apr 07 '23