[BUG][Python] AttributeError while processing response from server

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

While generating the TS29573_N32_Handshake.yaml to create python client, the code is incorrectly generated.

The python client after calling post_exchange_capability will raise error in the generated code. This is while processing the response from the server.

Traceback (most recent call last):
  File "main.py", line 29, in <module>
    api_response = api_instance.post_exchange_capability(sec_negotiate_req_data)
  File "./openapi_client/com/h21lab/TS29573_N32_Handshake/model/security_capability_negotiation_api.py", line 61, in post_exchange_capability
    return self.post_exchange_capability_with_http_info(sec_negotiate_req_data, **kwargs)  # noqa: E501
  File "./openapi_client/com/h21lab/TS29573_N32_Handshake/model/security_capability_negotiation_api.py", line 139, in post_exchange_capability_with_http_info
    return self.api_client.call_api(
  File ".../openapi_client/api_client.py", line 364, in call_api
    return self.__call_api(resource_path, method,
  File ".../openapi_client/api_client.py", line 208, in __call_api
    return_data = self.deserialize(response_data, response_type)
  File ".../openapi_client/api_client.py", line 280, in deserialize
    return self.__deserialize(data, response_type)
  File ".../python2_client/openapi_client/api_client.py", line 308, in __deserialize
    klass = getattr(openapi_client.com.h21lab.TS29573_N32_Handshake.handler, klass)
AttributeError: module 'openapi_client.com.h21lab.TS29573_N32_Handshake.handler' has no attribute 'SecNegotiateRspData'

Workaround to fix this, is to modify the generated code in the following way:

./openapi_client/com/h21lab/TS29573_N32_Handshake/model/security_capability_negotiation_api.py:147
# response_type='SecNegotiateRspData',  # noqa: E501
response_type='sec_negotiate_rsp_data',  # noqa: E501

After the python client is raising another error:

Traceback (most recent call last):
  File "main.py", line 29, in <module>
    api_response = api_instance.post_exchange_capability(sec_negotiate_req_data)
  File "./openapi_client/com/h21lab/TS29573_N32_Handshake/model/security_capability_negotiation_api.py", line 61, in post_exchange_capability
    return self.post_exchange_capability_with_http_info(sec_negotiate_req_data, **kwargs)  # noqa: E501
  File "./openapi_client/com/h21lab/TS29573_N32_Handshake/model/security_capability_negotiation_api.py", line 139, in post_exchange_capability_with_http_info
    return self.api_client.call_api(
  File ".../openapi_client/api_client.py", line 364, in call_api
    return self.__call_api(resource_path, method,
  File ".../openapi_client/api_client.py", line 208, in __call_api
    return_data = self.deserialize(response_data, response_type)
  File ".../openapi_client/api_client.py", line 280, in deserialize
    return self.__deserialize(data, response_type)
  File ".../openapi_client/api_client.py", line 319, in __deserialize
    return self.__deserialize_model(data, klass)
  File ".../openapi_client/api_client.py", line 648, in __deserialize_model
    if not klass.openapi_types and has_discriminator is False:
AttributeError: module 'openapi_client.com.h21lab.TS29573_N32_Handshake.handler.sec_negotiate_rsp_data' has no attribute 'openapi_types'

Workaround to fix this, is to modify the generated code:

./openapi_client/api_client.py:648
# if not klass.openapi_types and has_discriminator is False:
if not hasattr(klass, 'openapi_types') and has_discriminator is False:

openapi-generator version

5.0.0-SNAPSHOT

OpenAPI declaration file content or url

https://github.com/jdegre/5GC_APIs/blob/master/TS29573_N32_Handshake.yaml

Command line used for generation

Generated by openapi-generator-maven-plugin by using following options:

	<plugins>
            <plugin>
                <groupId>org.openapitools</groupId>
                <artifactId>openapi-generator-maven-plugin</artifactId>
                <version>5.0.0-SNAPSHOT</version>
                
                <configuration>
                    <generatorName>python</generatorName>
                    <output>${project.build.directory}/generated-sources</output>
                    <configOptions>
                    </configOptions>
               </configuration>
               
               <executions>
                   <execution>
                        <id>65</id>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                        <configuration>                      
                            <inputSpec>${project.basedir}/src/main/resources/TS29573_N32_Handshake.yaml</inputSpec>
                            <modelPackage>com.h21lab.TS29573_N32_Handshake.handler</modelPackage>
                            <apiPackage>com.h21lab.TS29573_N32_Handshake.model</apiPackage>
                            <invokerPackage>com.h21lab.TS29573_N32_Handshake.handler</invokerPackage>
                        </configuration>
                    </execution>
           	</executions>
            </plugin>
    	<plugins>

Steps to reproduce

Client code is simple:
main.py

from __future__ import print_function

import sys
# insert at 1, 0 is the script path (or '' in REPL)
sys.path.insert(1, './openapi_client/')

import time
import openapi_client
from openapi_client.rest import ApiException
from pprint import pprint

# Defining the host is optional and defaults to https://example.com/n32c-handshake/v1
# See configuration.py for a list of all supported configuration parameters.
configuration = openapi_client.Configuration(
    host = "http://127.0.0.1:8080/n32c-handshake/v1"
)

# 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 = openapi_client.SecurityCapabilityNegotiationApi(api_client)
    sec_negotiate_req_data = openapi_client.SecNegotiateReqData(sender="127.0.0.1", supported_sec_capability_list=["TLS", "string"])
    pprint(sec_negotiate_req_data)

    try:
        # N32-f Context Terminate
        api_response = api_instance.post_exchange_capability(sec_negotiate_req_data)
        pprint(api_response)
    except ApiException as e:
        print("Exception when calling SecurityCapabilityNegotiationApi->post_exchange_capability: %s\n" % e)

Server code is generated by python-flask generator and just implementing the following method in security_capability_negotiation_controller.py

import connexion
import six

from openapi_server.com.h21lab.TS29573_N32_Handshake.handler.problem_details import ProblemDetails  # noqa: E501
from openapi_server.com.h21lab.TS29573_N32_Handshake.handler.sec_negotiate_req_data import SecNegotiateReqData  # noqa: E501
from openapi_server.com.h21lab.TS29573_N32_Handshake.handler.sec_negotiate_rsp_data import SecNegotiateRspData  # noqa: E501
from openapi_server import util


def post_exchange_capability(body):  # noqa: E501
    """Security Capability Negotiation

     # noqa: E501

    :param sec_negotiate_req_data: Custom operation for security capability negotiation
    :type sec_negotiate_req_data: dict | bytes

    :rtype: SecNegotiateRspData
    """
    if connexion.request.is_json:
        sec_negotiate_req_data = SecNegotiateReqData.from_dict(connexion.request.get_json())  # noqa: E501
    return SecNegotiateRspData(sender="127.0.0.1", selected_sec_capability="TLS")

Related issues/PRs

Suggest a fix

Reproduce generation with TS29573_N32_Handshake.yaml and the shown Maven configuration, then inspect the generated security_capability_negotiation_api.py and api_client.py paths where response_type and model deserialization are used. Done means the generated Python client processes post_exchange_capability's response without either AttributeError.