FastAPI启动报错：Import error: No module named 'routers' 求助

尝试基于自定义API提供商构建FastAPI项目，按官方文档操作，执行fastapi run命令时触发错误：ERROR Import error: No module named 'routers'。已确认routers目录和项目根目录都存在__init__.py文件，相关代码及项目结构如下：

项目文件结构 #

main.py 代码 #

import sys
from fastapi import FastAPI, Depends, HTTPException
from sqlalchemy.orm import Session

#from core.config import settings
import sys
from fastapi import FastAPI, Depends, HTTPException
from sqlalchemy.orm import Session
sys.path.append('/routers/chat_order_router')  # Append the directory 
from  routers.chat_order_router import order_router

app = FastAPI()

app.include_router(order_router)

@app.get("/")
def read_root():
    return {"Hello": "World"}

chat_order_router.py 代码 #

from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
from typing import List

from dependencies import get_db
from schemas.chat_schema import ChatCreateSchema, ChatResponseSchema
from models.chat import Chat
import os

from dotenv import load_dotenv

from services.zus_backend_service import ZusBackendService  # Ensure this is correctly imported

import pytest
from httpx import Response

order_router = APIRouter(
    prefix="/chats_order",
    tags=["chats_order"],
    responses={404: {"description": "Not found"}},
)

load_dotenv()

# Dependency
def get_zus_service():
    base_uri = os.getenv('ZUS_BE_URL')  # Default value if not set
    client_name = os.getenv('ZUS_BE_NAME')
    client_secret = os.getenv('ZUS_BE_SECRET')

    if not base_uri or not client_name or not client_secret:
        raise Exception("Critical environment variables are missing for ZusBackendService")

    return ZusBackendService(base_uri, client_name, client_secret)

@order_router.get("/order-details/{order_id}")
async def order_details(order_id: str, zus_service: ZusBackendService = Depends(get_zus_service)):
    order_details = zus_service.get_order_details({"order_no": order_id})
    if not order_details:
        raise HTTPException(status_code=404, detail="Order not found")
    return order_details

@order_router.post("/", response_model=ChatResponseSchema, status_code=201)
def create_chat_orders(chat: ChatCreateSchema, db: Session = Depends(get_db)):
    new_chat = Chat(**chat.dict())
    db.add(new_chat)
    db.commit()
    db.refresh(new_chat)
    return new_chat

@order_router.get("/", response_model=List[ChatResponseSchema])
def read_chats_orders(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
    chats = db.query(Chat).offset(skip).limit(limit).all()
    return chats

@order_router.get("/{chat_id}", response_model=ChatResponseSchema)
def read_chats_orders(chat_id: int, db: Session = Depends(get_db)):
    chat = db.query(Chat).filter(Chat.id == chat_id).first()
    if chat is None:
        raise HTTPException(status_code=404, detail="Chat not found")
    return chat

@order_router.get("/check_order/{order_id}", status_code=200)
def check_order(order_id: int, db: Session = Depends(get_db)):
    """API endpoint to check if an order exists."""
    # Check directly if an order exists by querying the Chat table.
    order_exists = db.query(Chat).filter(Chat.order_id == order_id).first() is not None
    if order_exists:
        return {"message": "Order exists."}
    else:
        raise HTTPException(status_code=404, detail="Order not found")

问题原因及修复方案 #

1. sys.path 路径错误
   你添加的/routers/chat_order_router是系统根目录的绝对路径，并非项目内的routers目录。而且无需添加单个文件的路径，只需保证项目根目录在Python的搜索路径中即可。

2. 修复后的main.py代码
   由于main.py在项目根目录，routers是根目录的子目录，直接通过常规导入方式即可：

   from fastapi import FastAPI
   # 直接从routers目录导入，无需修改sys.path
   from routers.chat_order_router import order_router
   
   app = FastAPI()
   
   app.include_router(order_router)
   
   @app.get("/")
   def read_root():
       return {"Hello": "World"}
   

3. 额外检查项

   • 确认运行fastapi run时，当前工作目录是项目根目录（即main.py所在目录），否则需用fastapi run ./main.py指定文件路径。
   • 检查虚拟环境是否激活，避免因环境不一致导致模块找不到。

内容的提问来源于stack exchange，提问作者balron