Python object to JSON but only selected attributes

Question

I am trying to make my object from and to JSON. This object uses SQL Alchemy so using json.dumps(vars(self)) doesnt work. I am looking for the syntax to make this possible.

    def to_json(self):
        obj = {
            self.won,
            self.gameOver,
            self.allowMultiColor,
            self.pattern,
            self.board,
            self.round,
            self.totalRounds
        }

        return json.dumps(obj)

And then I want to redefine fields like this:

    def from_json(self, json_string):
        obj = json.loads(json_string)

        self.won = obj['won']
        self.gameOver = obj['gameOver']
        self.allowMultiColor = obj['allowMultiColor']
        self.pattern = obj['pattern']
        self.board = obj['board']
        self.round = obj['round']
        self.totalRounds = obj['totalRounds']

the to_json method doesnt' work. And when I try to get it again I get this error: TypeError: list indices must be integers or slices, not str

I am new to python so I don't yet know all the fancy syntax

score 1 · Accepted Answer · answered Apr 04 '20 at 10:54

1

obj must to be a dictinary to allow using strings as indices. So obj should look like this

obj = {
            'won':self.won,
            'gameOver':self.gameOver,
            ...
        }

answered Apr 04 '20 at 10:54

Banana

2,053
1
7
23

Ah, so it was the syntax I was missing. Thanks! – Roy Berris Apr 14 '20 at 09:36

score 0 · Answer 2 · answered Apr 04 '20 at 12:10

0

you can pass sqlalchemy objects into marshmallow's scheme, defining it's attributes into marshmallow's scheme. no problem with it.

answered Apr 04 '20 at 12:10

zo0M

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14

Python object to JSON but only selected attributes

2 Answers2