[BUG][PYTHON][PLUSS OTHERS] Enum variable names not update in all python converters

[mwilby]

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)

There is no need for a detailed report. This is a simple problem with a simple fix and it applies to all versions.

Description

There is a problem with the Python family of converters when processing enums.
Basically none of them substitutes the enum var extensions.

So using a simple scheme definition

maitred_format:
   type: integer
   title: Message Format
   enum:
     - 1
     - -1
     - 0
   x-enum-varnames:
     - JSON
     - Unknown
     - SIBEC
   x-enum-descriptions:
     - JSON Descriptions
     - Unknown stuff
     - SIBEC Description

The python converter creates this:

class MaitredFormat(int, Enum):
    """
    Encoding format of Payload.
    """

    """
    allowed enum values
    """
    NUMBER_1 = 1
    NUMBER_MINUS_1 = -1
    NUMBER_0 = 0

    @classmethod
    def from_json(cls, json_str: str) -> MaitredFormat:
        """Create an instance of MaitredFormat from a JSON string"""
        return MaitredFormat(json.loads(json_str))

If you look at the generated model info, the relevant part is found to be.

{
  ...,
  "model" : {
    ...,
    "classname" : "MaitredFormat",
    ...,
    "allowableValues" : {
      "values" : [ 1, -1, 0 ],
      "enumVars" : [ {
        "name" : "NUMBER_1",
        "isString" : false,
        "enumDescription" : "JSON Descriptions",
        "value" : "1"
      }, {
        "name" : "NUMBER_MINUS_1",
        "isString" : false,
        "enumDescription" : "Unknown stuff",
        "value" : "-1"
      }, {
        "name" : "NUMBER_0",
        "isString" : false,
        "enumDescription" : "SIBEC Descriptions.",
        "value" : "0"
      } ]
    },
    ...
  }
}

This is because updateEnumVarsWithExtensions() is never called and to fix it, its a simple matter of adding

    @Override
    public ModelsMap postProcessModels(ModelsMap objs) {
        // process enum in models
        return postProcessModelsEnum(objs);
    }

to the relevant Python????Codegen.java module.

There are a fair number of other language models that don't include a postProcessModels override, not sure if it matters, or not, but it probably does.

Taking a language that does include the call, in this case, csharp, you generate the correct form of enum, i.e.

namespace Org.OpenAPITools.Model
{
    public enum MaitredFormat
    {
        JSON = 1,
        Unknown = -1,
        SIBEC = 0,
    }
}

This is because the model has been processed and looks like this.

{
  ...,
  "model" : {
    ...,
    "classname" : "MaitredFormat",
    ...,
    "allowableValues" : {
      "values" : [ 1, -1, 0 ],
      "enumVars" : [ {
        "name" : "JSON",
        "isString" : false,
        "enumDescription" : "JSON Descriptions",
        "value" : "1"
      }, {
        "name" : "Unknown",
        "isString" : false,
        "enumDescription" : "Unknown stuff",
        "value" : "-1"
      }, {
        "name" : "SIBEC",
        "isString" : false,
        "enumDescription" : "SIBEC Descriptions.",
        "value" : "0"
      } ]
    },
    ...
  }
}

Suggest a fix

Repeat adding

    @Override
    public ModelsMap postProcessModels(ModelsMap objs) {
        // process enum in models
        return postProcessModelsEnum(objs);
    }

to the relevant Python????Codegen.java module.

[wing328]

This is because updateEnumVarsWithExtensions() is never called and to fix it, its a simple matter of adding

can you please file a PR with the suggested fix?

[roishacham]

@wing328 @mwilby

Any updates on a fix for this issue? I'm encountering this as well.

[VBA-N7]

I'm encountering the same problem and this is very annoying. It would be great to have some news 😄

openapi: 3.0.0
info:
  version: 1.0.0
  title: Weather API
paths: {}

components:
  schemas:
    WeatherType:
      type: integer
      format: int32
      enum:
        - 42
        - 18
        - 56
      x-enum-descriptions:
        - 'Blue sky'
        - 'Slightly overcast'
        - 'Take an umbrella with you'
      x-enum-varnames:
        - Sunny
        - Cloudy
        - Rainy

The command i used
docker run --rm -v "${PWD}:/local" openapitools/openapi-generator-cli generate -i /local/mon_api.yaml -g python-flask -o /local/dist

The generated python file:

from datetime import date, datetime  # noqa: F401

from typing import List, Dict  # noqa: F401

from openapi_server.models.base_model import Model
from openapi_server import util


class WeatherType(Model):
    """NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).

    Do not edit the class manually.
    """

    """
    allowed enum values
    """
    NUMBER_42 = 42
    NUMBER_18 = 18
    NUMBER_56 = 56
    def __init__(self):  # noqa: E501
        """WeatherType - a model defined in OpenAPI

        """
        self.openapi_types = {
        }

        self.attribute_map = {
        }

    @classmethod
    def from_dict(cls, dikt) -> 'WeatherType':
        """Returns the dict as a model

        :param dikt: A dict.
        :type: dict
        :return: The WeatherType of this WeatherType.  # noqa: E501
        :rtype: WeatherType
        """
        return util.deserialize_model(dikt, cls)

[0xMattijs]

While postProcessModelsEnum is called here:

openapi-generator/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java

Line 870 in 73f2d82

objs = postProcessModelsEnum(objs);

its effects are overwritten by the code block further down: https://github.com/OpenAPITools/openapi-generator/blob/73f2d8289b2d4069675c79ea5375d9c58ea1853c/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java#L986C1-L998C14

I created PR #18566 preventing the NUMBER_X transformation to run if x-enum-varnames is provided.

[hxomer]

x-enum-varnames seem to also be ignored in python to string values enum - even in the new version with the merged PR, I see that the merged PR only handled the number use case, @0xMattijs is this on purpose?

[0xMattijs]

No that was not on purpose. I guess this can be simply fixed by including the test also for the string case:

openapi-generator/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java

Lines 990 to 992 in db6709f

	model.vendorExtensions.putIfAbsent("x-py-enum-type", "str");
	// update `name`, e.g.
	enumVars.put("name", toEnumVariableName((String) enumVars.get("value"), "str"));

Something like this:

            if ((Boolean) enumVars.get("isString")) {
                model.vendorExtensions.putIfAbsent("x-py-enum-type", "str");
                // update `name`, e.g.
                if (model.vendorExtensions.get("x-enum-varnames") == null) {
                    enumVars.put("name", toEnumVariableName((String) enumVars.get("value"), "str"));
                }
            } else {
                model.vendorExtensions.putIfAbsent("x-py-enum-type", "int");
                // Do not overwrite the variable name if already set through x-enum-varnames
                if (model.vendorExtensions.get("x-enum-varnames") == null) {
                    enumVars.put("name", toEnumVariableName((String) enumVars.get("value"), "int"));
                }
           }

[PidgeyBE]

I'll create a PR with the proposed changes