My question may be silly, and I am no expert. What am trying to do is to manipulate the JSON generated by django.core.serializers.serialize .
I'v searched the web to try and find how to serialize some picked fields in my Model.
There is a an argument fields that takes an array of what I want to serialize, but what do I do if I want to add some calculated field that is not stored in the DB?
I've searched a lot with no results, maybe there is something like a method or a class I don't know of yet that may solve it?
This is just a work around ,I'v managed to use model_to_dict to get a dict object then manipulate it as i want then json.dumps to convert it .
Am not worried about deserialization as i can manage to do so as in the serialization but however am only doing this so i can get forward in my app , and this is a silly work around , so am not accepting it as an answer ,still waiting for the experts for some more robust solution.
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I am running a graphql query using aiographql-client and getting back a GraphQLResponse object, which contains a raw dict as part of the response json data.
This dictionary conforms to a schema, which I am able to parse into a graphql.type.schema.GraphQLSchema type using graphql-core's build_schema method.
I can also correctly get the GraphQLObjectType of the object that is being returned, however I am not sure how to properly deserialize the dictionary into a python object with all the appropriate fields, using the GraphQLObjectType as a reference.
Any help would be greatly appreciated!
I'd recommend using Pydantic to the heavy lifting in the parsing.
You can then either generate the models beforehand and select the ones you need based on GraphQLObjectType or generate them at runtime based on the definition returned by build_schema.
If you really must define your models at runtime you can do that with pydantic's create_model function described here : https://pydantic-docs.helpmanual.io/usage/models/#dynamic-model-creation
For the static model generation you can probably leverage something like https://jsontopydantic.com/
If you share some code samples I'd be happy to give some more insights on the actual implementation
I faced the same tedious problem while developing a personal project.
Because of that I just published a library which has the purpose of managing the mappings between python objects and graphql objects (python objects -> graphql query and graphql response -> python objects).
https://github.com/dapalex/py-graphql-mapper
So far it manages only basic query and response, if it will become useful I will keep implementing more features.
Try to have a look and see if it can help you
Coming back to this, there are some projects out there trying to achieve this functionality:
https://github.com/enra-GmbH/graphql-codegen-ariadne
https://github.com/sauldom102/gql_schema_codegen
This question already has answers here:
How to make a class JSON serializable
(41 answers)
Closed 6 months ago.
I'm noting that the methods I am looking at to serialize a variable into JSON in python don't really seem to handle it all that well, and for my purpose I just want to quickly dump an objects contents into a string format so I can pick out what I actually want to write custom code to handle. I want to be able to dump the main fields at the very least of any class I pass the python serializer and really if its worth the name this should work.
So take the following code:
import json
c = SomeClass()
#causes an error if any field in someclass has another class instance.
json.dumps(c)
leads to..
TypeError: Object of type {Type} is not JSON serializable
Are there any modules other people have used that would solve my problem ? I really don't see how there would not be. Or maybe one might explain how to circumvent this error ?
The goal is to simply get some output to look at. If I wrote a recursion loop in c# using reflection, excepting circular references, it wouldn't be difficult, so I cannot imagine python users have never tackled this exact issue and I'm not satisfied with the answers that I have seen in older posts which seem to suggest a lot of custom tinkering for something seems to be designed in spirit to just dump any old object's contents out.
I don't even need complex traversal is the funny part, though it would be nice. I just need a dump of the property values which are primitive types in many cases. I know this is possible because the debugger does it.
Additionally I looked at one of the methods given indicating to use default lambda to specify how the json serializer should descend into the object:
json.dumps(o, default=lambda k: k.__dict__)
and the object does not contain the standard dict member.
in the end I just ended up writing a class to do this.
edit:
Here use this now you can one way serialize a class structure with this nifty little bit of code that I added to address my problem with f**** discord.py !
end edit
There is no fire and forget option that would disentangle a mass of information.
The way of creating this solution would be to manage seperate lists of subclasses to make sure not to recurse until a stackoverflow is reached.
The slots_ can be used with getattr(o,name) when hasattr(o,'dict') is False.
But the answer is you'd have to create a solution that basically does the job that the json serializer should be doing and cut out circular reference by determining the unique complex types and writing them in seperate tabular entries in the json file and replacing them in the referencing classes with ids.
That way you could cross reference these objects while glancing at them.
However the short answer is no. Python does not offer an out of the box way of doing this and all the provided answers encountered thus far only solve a single use-case or scenario, and do not create a incorporated solution to the problem which the above mentioned algorithm WOULD by NORMALIZING the class data into unique elements.
I have scraped data from a website using their API on a Django application. The data is JSON (a Python dictionary when I retrieve it on my end). The data has many, many fields. I want to store them in a database, so that I can create endpoints that will allow for lookup and modifications (updates). I need to use their fields to create the structure of my database. Any help on this issue or on how to tackle it would be greatly appreciated. I apologize if my question is not concise enough, please let me know if there is anything I need to specify.
I have seen many, many people saying to just populate it, such as this example How to populate a Django sqlite3 database. The issue is, there are so many fields that I cannot go and actually create the django model fields myself. From what I have read, it seems like I may be able to use serializers.ModelSerializer, although that seems to just populate a pre-existing db with already defined model.
Tricky to answer without details, but I would consider doing this in two steps - first, convert your json data to a database schema, for example using a tool like sqlify: https://sqlify.io/convert/json/to/sqlite
Then, create a database from the generated schema file, and use inspectdb to generate your django models: https://docs.djangoproject.com/en/2.2/ref/django-admin/#inspectdb
You'll probably need to tweak the generated schema and/or models, but this should go a long way towards automating the process.
I would go for a document database, like Elasticsearch or MongoDB.
Those are made for this kind of situation, look it up.
I am working on a project (the tech is Django Framework), and I have been assigned a task to create a functionality to store translations and create new translations of a given json file. The json file includes key, value pairs where the key is a unique key that the front-end of the app uses to tell where the text goes, which is the value. For example, { 'restaurant.wait':'Please wait while we process your order'}. So, I have a default json file with keys and values in English, and say we need a translation, I need to be able to get the values (easy part), show them to the translator, then he will input translations in a form with the translation for the given text. Now here comes the hard part, I need to then take this translation and map it back to the same keys in the json file. Another feature that this needs to have is to be able to export/import csv files of translations and then dynamically add them. I can't seem to figure out how to start solving this problem. I tried thinking of a model that I could have to hold the keys and to have another model that would be the translations, but I get confused how I should input the default values. I've just come to a stalemate on this problem and I am having a hard time thinking up of a clean way to do this. I also tried to go about it without a model for a database and just use a view to do this, but there is a problem with keeping order of the keys, and mapping the translations back to the correct keys. Please, I would really appreciate any help I can get with how I should go about to implement this. Thank you, in advance I hope there is enough detail that you can understand the issue I am having.
So I have a function which creates a dynamic model. I accomplish this in a way very similar to AuditTrail (see django wiki).
Sample of code is here:
https://gist.github.com/0212845ae00891efe555
Is there any way I can make a dynamically-generated class pickle-able? Ideally something thats not a crazy monkeypatch/hack?
I am aware of the problem where pickle can't store a generated or dynamic class. I solved this by rigging in my dynamic type into the modules dict like so:
new_class = type(name, (models.Model,), attrs)
mod = sys.modules[new_class.__module__]
mod.__dict__[new_class.__name__] = new_class
It's FAR from a clean or elegant solution, so if someone can think of a more django-friendly way to make this happen, I am all ears. However, the above code does work.
The reason there aren't answers for this is because the answer is likely hackish. I don't think you can unpickle an object in Python without knowing the structure of the class on the receiving end without some sort of hackish solution. A big reason pickle doesn't support it is probably because it's a fantastic way to introduce malicious code into your application.
http://www.mofeel.net/871-comp-lang-python/2898.aspx explains a bit why dynamically created classes can't be unpickled.
In every case, I've either just serialized a dictionary of the attributes of the object using the dict method, or just figured out some awful work around. I hope you come up with something better.
Good Luck!