Nest assignment is ignored smd['some-key']['x']

[marcelomanzo]

from shared_memory_dict import SharedMemoryDict
smd = SharedMemoryDict(name='tokens', size=1024)
smd['some-key'] = {}
smd['some-key']['x'] = 1 #this statement is ignored
print(smd) #output {'some-key': {}}

[druidance]

Was baffled by this limitation as well.

As a work around, how about juggling the nested object?

from shared_memory_dict import SharedMemoryDict

smd = SharedMemoryDict(name='tokens', size=1024)

temp = smd['some-key'] = {}
temp['x'] = 1
smd['some-key'] = temp
print(smd) #output {'some-key': {'x': 1}}

edit: added more comments

[githubdontbanmeagain]

Is there a better fix for this? The "juggling" above throws an error.

[druidance]

Is there a better fix for this? The "juggling" above throws an error.

Hey,

Could you show the error you're getting there?

[githubdontbanmeagain]

client is a initialized class, key is a str

smd = SharedMemoryDict(name="123", size=1024)
smd["data"]

def add_to_data():
    temp = smd["data"]
    temp[key] = {
            "key": key,
            "client": client,
    }
    smd["data"] = temp

def add_to_data()

Traceback (most recent call last):
  File "C:\Users\x\x.py", line 34, in x
    smd"data"] = temp
  File "C:\Users\x\AppData\Local\Programs\Python\Python39\lib\site-packages\shared_memory_dict\dict.py", line 96, in __setitem__
    db[key] = value
  File "C:\Users\x\AppData\Local\Programs\Python\Python39\lib\contextlib.py", line 124, in __exit__
    next(self.gen)
  File "C:\Users\x\AppData\Local\Programs\Python\Python39\lib\site-packages\shared_memory_dict\dict.py", line 89, in _modify_db
    self._save_memory(db)
  File "C:\Users\x\AppData\Local\Programs\Python\Python39\lib\site-packages\shared_memory_dict\dict.py", line 177, in _save_memory
    data = self._serializer.dumps(db)
  File "C:\Users\x\AppData\Local\Programs\Python\Python39\lib\site-packages\shared_memory_dict\serializers.py", line 44, in dumps
    return pickle.dumps(obj, pickle.HIGHEST_PROTOCOL)
AttributeError: Can't pickle local object 'WeakValueDictionary.__init__.<locals>.remove'

[githubdontbanmeagain]

I tested it without client, that seems to be the issue. I'm not quite sure how to go about this

[githubdontbanmeagain]

Got this error when using the built in JSONSerializer instead, as I read pickle has problems with local objects:

  File "C:\Users\x\AppData\Local\Programs\Python\Python39\lib\site-packages\shared_memory_dict\serializers.py", line 31, in dumps
    raise SerializationError(obj)
shared_memory_dict.serializers.SerializationError: Failed to serialize data: {...

[druidance]

client is a initialized class, key is a str

I think this is the problem you've got there as it relates to the fact that you cannot assign custom objects (that cannot be pickled) as values. Change your client type to something more common - such as str or int - and you'll get the result.

from shared_memory_dict import SharedMemoryDict

smd = SharedMemoryDict(name="123", size=1024)
smd["data"] = {}


def add_to_data(key, client):
    temp = smd["data"]
    temp[key] = {
            "key": key,
            "client": client,
    }
    smd["data"] = temp

key = 1
client = 'Client'
add_to_data(key, client)

What is the reason for passing such client object between the processes? Does it hold some kind of important information you want to update?

[githubdontbanmeagain]

Yes, the client class has functions and data that I need to access in other files. So simply using a string would not really work..

I tried using dill (a drop in replacement for pickle with more support for custom types), but I face different issues there.

I could store the clients in a local dict in that file, and then send read/write commands through shared memory, but that would really be pain, I'm trying to find a clean solution.

[druidance]

How about refactoring class data out to DTOs that can be passed around through the SharedMemoryDict functionality?

I think that was the core concept behind shared_memory objects.

[githubdontbanmeagain]

That would kinda be a little complex, the functions need the context of the client class to work properly, as there are multiple clients initialized

[druidance]

Sorry, but I'm afraid I cannot help any further since I do not possess enough information about the logic you're trying to implement. It seems to be out of SharedMemoryDict scope.

[githubdontbanmeagain]

All good, it's an issue with pickle/dill.