来自 OpenAPI yaml 文件的 FastAPI 架构

Question

I'm looking for a way to initialize a FastAPI server, with an existing OpenAPI YAML schema file.

The docs do describe how to modify the auto-generated schema, but I'm looking for something like Connexion , which can generate the validators on-the-fly.

• a related question can be found here
• a tool to generate a FastAPI project from an OpenAPI schema file can be found here , but did not work in my case (the project is still experimental)

Edit

I've traced down the offending property to this one:

class MyParameters(BaseModel):
    ...
    ModelName: Optional[ModelName] = Field(None, description='')
    ...

The matching object schema in openapi.yaml:

MyParameters:
    type: object
    properties:
        ...
        ModelName:
            type: string
            enum: [XYZ]
            description: ""
        ...

ModelName is not mandatory.

Answer 1

After resolving the issue with fastapi-code-generator , I've opted to use it.

For future readers, who use Python 3.7 , the issue was a missing import in the generated models.py file:

from __future__ import annotations

Adding it at the top of models.py resolved the issue.