[BUG] [PYTHON] Generated client breaks on to_dict() method

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• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
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• What’s the actual output vs expected output?
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Description

The .to_dict() function causes “AttributeError: ‘dict’ object has no attribute” error.

openapi-generator version

5.2.1

OpenAPI declaration file content or url

I used $ref with external files: https://gist.github.com/Valmoz/16503c5ce996d27982722959733b6955 the paths are:

• openapi.yaml
• models/responses/UserInfoResponse.yaml
• models/schemas/User.yaml

Generation Details

openapi-generator-cli generate -i openapi.yaml -g python -o generated/openapi/python/

Steps to reproduce

I tried to use the generated client from a dedicated python script:

from openapi_client.model.user_info_response import UserInfoResponse
from openapi_client.api import user_api

configuration = openapi_client.Configuration(
    host = 'http://api-v2.example.it'
)
configuration.access_token = access_token

# Enter a context with an instance of the API client
with openapi_client.ApiClient(configuration) as api_client:
    # Create an instance of the API class
    api_instance = user_api.UserApi(api_client)
    
    try:
        # Get User Info
        api_response: UserInfoResponse = api_instance.get_user_info()
        return api_response.to_dict()
    except openapi_client.ApiException as e:
        print("Exception when calling UserApi->get_user_info: %s\n" % e)

When this code is executed, (more precisely: the to_dict() function) I obtain this error: AttributeError: ‘dict’ object has no attribute ‘_composed_schemas’

Manually modifying the generated model_utils.py file at line 1634 (see next session), I was able to fix this error, but then I obtained another one: AttributeError: ‘dict’ object has no attribute ‘_data_store’

Modifying also line 1640, I am able to retrieve:

{
  "data": {
    "email": "[e-mail]", 
    "first_name": "Matteo", 
    "hash": "44444", 
    "id": 2, 
    "last_name": "Rossi", 
    "name": "Matteo Rossi", 
    "picture": null
  }, 
  "email_confirmation_state": {
    "need_confirmation": false
  }, 
  "info": {
    "need_marketing_consents_confirmation": false, 
    "need_password_change": false, 
    "need_terms_of_service_confirmation": false
  }
}

Related issues/PRs

I didn’t find any…

Suggest a fix

it seems possible to avoid the issues checking if model_instance contains the missing keys.

I modified the generated model_utils.py line 1634 as follows:

if '_composed_schemas' in model_instance and model_instance._composed_schemas:
    ...

For the second error, I wrapped the for statement at line 1640 in an if statement as follows:

if '_data_store' in model_instance:
    for attr, value in model_instance._data_store.items():
        ...

N.B.: I also noticed that lines 1652-1664 have been indented with one space less than the rest of the file (3 instead of 4)…

[valmoz]

I think that it should be enough to modify the following file: modules/openapi-generator/src/main/resources/python/model_utils.mustache lines 1336-1342

[ghost]

I also produced this with version 5.2.1. I upgrade to 5.3.1 and the error was immediately obvious to me. I had set a property as either (integer, nullable) but was receiving a string. At least in my case, it wasn’t a bug, just good o’l user error and an un-helpful error message.