CODEWITHSUNDEEP
pythonwebsocket
Sam B.
Sam B.

Reputation: 3043

python websockets; parse json

I have this script using websockets 

import asyncio
import websockets
import json

async def echo(websocket, path):
    async for message in websocket:
        print(message)
        await websocket.send(message)

asyncio.get_event_loop().run_until_complete(
    websockets.serve(echo, 'localhost', 8765))
asyncio.get_event_loop().run_forever()

I send data from javascript that's in json format

var socket = new WebSocket('ws://localhost:8765');
socket.send(temp1);
temp1
> {img_width: 600, img_height: 399, areas: Array(1)}

this is what's printed back by python

(pixelart) sam@sam-Lenovo-G51-35:~/code/pixelart$ python path.py
[object Object]

I've tried to check for ways of accessing it's attributes to see if I can get to the data using print(dir(message)) this is what I got back

['__add__', '__class__', '__contains__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__mod__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmod__', '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', 'capitalize', 'casefold', 'center', 'count', 'encode', 'endswith', 'expandtabs', 'find', 'format', 'format_map', 'index', 'isalnum', 'isalpha', 'isdecimal', 'isdigit', 'isidentifier', 'islower','isnumeric', 'isprintable', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'maketrans', 'partition', 'replace', 'rfind', 'rindex', 'rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']

looks more like binders for a string so I tried to check it's type print(type(message))

(pixelart) sam@sam-Lenovo-G51-35:~/code/pixelart$ python path.py
<class 'str'>

it looks like it converts the object into a string.

Upvotes: 5

Views: 5786

Answers (1)

Jamie Scott
Jamie Scott

Reputation: 452

In JavaScript, [object Object] means you've tried to convert an object which does not define how to convert itself to a string to a string.

So you need to first convert your JSON object to a JSON string using JSON.stringify():

var socket = new WebSocket('ws://localhost:8765');
socket.send(JSON.stringify(temp1);

Now python path.py should print the JSON string you sent.

To convert that JSON string in Python side of things to a dict (so you can use it natively), you can use json.loads(string) (loads meaning load from string).

Upvotes: 3

Related Questions