fastapi - 错误 : Error loading ASGI app. 导入字符串 "main"的格式必须为 ":"

Question

尝试使用 uvicorn 测试我的第一个 FastAPI 应用程序。

以下代码是在Jupyter Notebook上写的，保存为'main.py'在目录:/home/user

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
async def root():
    return {"message": "Hello World"}

从我正在运行的同一目录:

$uvicorn main --reload

它抛出以下错误:

ERROR: Error loading ASGI app. Import string "main" must be informat ":".

Answer 1

如错误所示，“字符串 main 必须采用 "<module>:<attribute>" 格式”。因此，您应该使用:

uvicorn main:app --reload

我强烈建议您查看 FastAPI tutorial .

The command uvicorn main:app refers to:

• main: the file main.py (the Python "module").
• app: the object created inside of main.py with the line app = FastAPI().
• --reload: make the server restart after code changes. Only use for development.