[BUG] when using openapi-generator for pythno with a dictionary of list, the generated api_client fails

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When using openapi-generator with the json https://github.com/NASA-PDS/pds-api-client/blob/main/swagger.json

and command line

openapi-generator generate -g python -i swagger.json --package-name pds.api_client --additional-properties=packageVersion=0.2.0

the package fails with error:

Traceback (most recent call last):
File "client-demo.py", line 16, in
api_response = collections.get_collection(start=0, limit=20)
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api/collections_api.py", line 179, in get_collection
return self.get_collection_with_http_info(**kwargs) # noqa: E501
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api/collections_api.py", line 285, in get_collection_with_http_info
collection_formats=collection_formats)
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 370, in call_api
_preload_content, _request_timeout, _host)
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 209, in __call_api
return_data = self.deserialize(response_data, response_type)
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 281, in deserialize
return self.__deserialize(data, response_type)
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 320, in __deserialize
return self.__deserialize_model(data, klass)
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 659, in __deserialize_model
kwargs[attr] = self.__deserialize(value, attr_type)
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 298, in __deserialize
for sub_data in data]
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 298, in
for sub_data in data]
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 320, in __deserialize
return self.__deserialize_model(data, klass)
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 659, in __deserialize_model
kwargs[attr] = self.__deserialize(value, attr_type)
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 303, in __deserialize
for k, v in six.iteritems(data)}
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 303, in
for k, v in six.iteritems(data)}
File "/Users/loubrieu/PycharmProjects/pds-api-client/pds/api_client/api_client.py", line 309, in __deserialize
klass = getattr(pds.api_client.models, klass)
AttributeError: module 'pds.api_client.models' has no attribute 'list'

When running for example

python client-demo.py

(find the file https://github.com/NASA-PDS/pds-api-client/blob/main/client-demo.py).

I was expecting the command to run without failre and return the response of the API server.

openapi-generator version

% openapi-generator --version
openapi-generator-cli 4.3.1
commit : 003165c
built : 2020-05-06T09:38:39Z
source : https://github.com/openapitools/openapi-generator
docs : https://openapi-generator.tech/

OpenAPI declaration file content or url

https://github.com/NASA-PDS/pds-api-client/blob/main/swagger.json

Generation Details

openapi-generator generate -g python -i swagger.json --package-name pds.api_client --additional-properties=packageVersion=0.2.0

Steps to reproduce

Related issues/PRs

Suggest a fix

Here is a pull request
https://github.com/OpenAPITools/openapi-generator/pull/10004

Start by running the listed openapi-generator command with swagger.json, then inspect the generated pds/api_client/api_client.py and collections_api.py while reproducing the failure with client-demo.py. Done means the generated client handles the dictionary-of-list response without the AttributeError and client-demo.py returns the API response; a pull request for this issue is already linked in the report.