I’m developing an application using FastAPI and Pydantic, and I’m encountering a circular import issue when trying to define my data models.
Here are the relevant files:
src/schemas/user.py
from typing import List
from pydantic import BaseModel
from src.schemas.blog import ShowBlog # Import causing circular dependency
class ShowUser(BaseModel):
username: str
email: str
blogs: List[ShowBlog]
class Config:
from_attributes = True
class User(BaseModel):
username: str
email: str
password: str
src/schemas/blog.py
from pydantic import BaseModel
from src.schemas.user import ShowUser # Import causing circular dependency
class Blog(BaseModel):
title: str
description: str
user_id: int
class ShowBlog(BaseModel):
id: int
title: str
description: str
written_by: ShowUser
class Config:
from_attributes = True
When I run the application, I receive the following error:
ImportError: cannot import name 'ShowBlog' from partially initialized module 'src.schemas.blog' (most likely due to a circular import)
How can I resolve this circular import issue while keeping my FastAPI application structured? Are there best practices for organizing Pydantic models to avoid such problems?
1
I had a similiar problem using SQLModel with fastapi. This is what worked for me: Replace the dependency in one of the schema files with the name in quotations and don’t import it there:
from typing import List
from pydantic import BaseModel
class ShowUser(BaseModel):
username: str
email: str
blogs: List["ShowBlog"]
class User(BaseModel):
username: str
email: str
password: str
This seems to work also in your example!
2