Python save list and read data from file

Question

Basically I would like to save a list to python and then when the program starts I would like to retrieve the data from the file and put it back into the list.
So far this is the code I am using

mylist = pickle.load("save.txt")
...
saveToList = (name, data)
mylist.append(saveList)
import pickle
pickle.dump(mylist, "save.txt")

But it just returns the following error: TypeError: file must have 'read' and 'readline' attributes

Arthur Tacca · Accepted Answer · 2016-10-19T14:18:28.913

4

You need a file object, not just a file name. Try this for saving:

pickle.dump(mylist, open("save.txt", "wb"))

or better, to guarantee the file is closed properly:

with open("save.txt", "wb") as f:
    pickle.dump(mylist, f)

and then this for loading:

with open("save.txt", "rb") as f:
    mylist = pickle.load(f)

Also, I suggest a different extension from .txt, like maybe .dat, because the contents is not plain text.

edited Oct 19 '16 at 14:18

answered Oct 19 '16 at 14:14

Arthur Tacca

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I get TypeError: Function takes at most 1 positional arguments (2 given) – Octo Oct 19 '16 at 14:17
@DarkchiliSlayer Oops, fixed – Arthur Tacca Oct 19 '16 at 14:18

score 1 · Answer 2 · answered Oct 19 '16 at 14:15

1

with open("save.txt", "w") as f:
    pickle.dump(f, mylist)

Refer to python pickle documentation for usage.

answered Oct 19 '16 at 14:15

TurtleIzzy

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score 1 · Answer 3 · answered Oct 19 '16 at 14:18

1

pickle.dump accept file object as argument instead of filename string

pickle.dump(mylist, open("save.txt", "wb"))

answered Oct 19 '16 at 14:18

Skycc

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Python save list and read data from file

3 Answers3