Mr. Hong

[singermangame9-wq]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the documentation, with the integrated search.
• I already searched in Google "How to X" and didn't find any information.
• I already read and followed all the tutorials in the docs and didn't find an answer.

Example Code

I step by step to learn with SQLModel[Tutorial - User Guide] .
When I copy the code from the teaching webpage chapter and find some problem that I can't solve.
SQLModel[Code Structure and Multiple Files ](https://sqlmodel.tiangolo.com/tutorial/code-structure/ )

Description

Q1,
app.py
from sqlmodel import Session

from .database import create_db_and_tables, engine
from .models import Hero, Team

def create_heroes():
with Session(engine) as session:
team_z_force = Team(name="Z-Force", headquarters="Sister Margaret's Bar")

    hero_deadpond = Hero(
        name="Deadpond", secret_name="Dive Wilson", team=team_z_force
    )
    session.add(hero_deadpond)
    session.commit()

    session.refresh(hero_deadpond)

    print("Created hero:", hero_deadpond)
    print("Hero's team:", hero_deadpond.team)

def main():
create_db_and_tables()
create_heroes()

if name == "main":
main()

execute...
/Users/hongjunjie01/my-fastapi-project/venv/bin/python /Users/hongjunjie01/my-fastapi-project/app.py
Traceback (most recent call last):
File "/Users/hongjunjie01/my-fastapi-project/app.py", line 3, in
from .database import create_db_and_tables, engine
ImportError: attempted relative import with no known parent package

Process finished with exit code 1

Q2
init.py
from .models import Hero, Team
from .database import engine

execute...
/Users/hongjunjie01/my-fastapi-project/venv/bin/python /Users/hongjunjie01/my-fastapi-project/init.py
Traceback (most recent call last):
File "/Users/hongjunjie01/my-fastapi-project/init.py", line 1, in
from .models import Hero, Team
ImportError: attempted relative import with no known parent package

Process finished with exit code 1

Operating System

macOS

Operating System Details

Macmini m6 16GB with macos.

Project Version

Fastapi(learning)

Python Version

Python 3.15.0

Additional Context

I step by step to learn with Tutorial - User Guide.
But when I learn this chapter and find some error that I can't find problem.Code Structure and Multiple Files

[Sagargupta16]

Run it as a module from the folder above the package instead of running the file. from .database import ... is a relative import, and it only works when Python knows app.py belongs to a package. python app.py runs the file as a standalone script, so there is no parent package and you get exactly that ImportError. The tutorial covers this under "Run It in the Command Line" on the page you linked: python -m project.app, run from the directory that contains project/.

Your three files sit directly in my-fastapi-project/, so the equivalent is one level up:

cd /Users/hongjunjie01
my-fastapi-project/venv/bin/python -m my-fastapi-project.app

I ran that layout here on Python 3.13 and the hyphenated folder name works with -m. If you would rather match the tutorial exactly, make a project/ folder inside my-fastapi-project/, move __init__.py, app.py, database.py and models.py into it, and run venv/bin/python -m project.app from my-fastapi-project/.

Q2: __init__.py is never run on its own. It executes when the package is imported, which python -m project.app does for you.

The "Process finished with exit code 1" line means PyCharm's Run button ran the file as a script. In Run > Edit Configurations, switch the target from "Script path" to "Module name", enter project.app (or my-fastapi-project.app), and set "Working directory" to the folder that contains the package.

[singermangame9-wq]

Thanks for your kindly answer !
I am beginner and will try it.

[singermangame9-wq]

Sorry , I have another question in chapter 'Simple Hero API with FastAPI' (https://sqlmodel.tiangolo.com/tutorial/fastapi/simple-hero-api/)

I also copy webpage code to Pycharm.
Line 26
@app.on_event("startup")
def on_startup():
create_db_and_tables()

Pycharm shows problem:

on_event is deprecated, use lifespan event handlers instead.
Read more about it in the
[FastAPI docs for Lifespan Events](https://fastapi.tiangolo.com/advanced/events/).

Pycharm runs shows problem:
/Users/hongjunjie01/my-fastapi-project/main.py:26: DeprecationWarning:
on_event is deprecated, use lifespan event handlers instead.

    Read more about it in the
    [FastAPI docs for Lifespan Events](https://fastapi.tiangolo.com/advanced/events/).

@app.on_event("startup")

Process finished with exit code 0

Please help me.

[Sagargupta16]

It is a warning, not an error. Your run ended with Process finished with exit code 0, so the app started and the table was created. You can keep following the tutorial as written.

To make the warning go away, replace the on_event block with a lifespan function and pass it to FastAPI():

from contextlib import asynccontextmanager

from fastapi import FastAPI


@asynccontextmanager
async def lifespan(app: FastAPI):
    create_db_and_tables()
    yield


app = FastAPI(lifespan=lifespan)

Everything before yield runs once at startup, which is what on_startup() did. Delete the @app.on_event("startup") function and keep the rest of the file the same. This is the pattern in the FastAPI docs for Lifespan Events. I ran the tutorial file both ways on FastAPI 0.162.0 and SQLModel 0.0.48: the original prints the warning, the lifespan version starts clean and creates the table.

You will see the same warning in every later chapter because the SQLModel docs still use on_event everywhere. The maintainer closed the pull requests that switch the docs to lifespan (#1687) because he plans to rework that part first, so the tutorial will keep showing the old form for now. Apply the same replacement in each chapter.

[singermangame9-wq]

Thanks!

Sorry, I changed with your code but it still shows warning without creating database.db.
It should be my environment problem.
I will try another way with 'Fastapi learn chapter'

[Sagargupta16]

The database is created when the server starts, and nothing in your run starts a server. PyCharm's Run button runs python main.py, which only defines app and exits with code 0, so lifespan never runs and database.db is never written. My earlier line that the table had been created was wrong, for the same reason: the old on_startup never ran either.

Start the server from the PyCharm terminal, in the folder that holds main.py:

venv/bin/uvicorn main:app --reload

Then open http://127.0.0.1:8000/docs. database.db appears in the project tree as soon as the server starts. Stop it with Ctrl+C. This is the "Run the FastAPI Server" step of the chapter; the tutorial writes it as fastapi dev main.py, which works once you install "fastapi[standard]" in the venv. The same command runs every later chapter.

Also delete the @app.on_event("startup") block that is still at the bottom of your file (lines 28 to 30 in your screenshot). The lifespan function already does that job, and the leftover block is what keeps printing the deprecation warning.

I ran your file on Python 3.13 with SQLModel 0.0.48: python main.py exits without creating the file, uvicorn main:app creates it and logs CREATE TABLE hero.

[singermangame9-wq]

Thanks for your kindly suggestion!

In later chapter , I run this code in terminal(local) that shows success with database.db.
FastAPI Path Operations for Teams - Other Models

In another way , I run with "pycharm triangle button" and get the same warning.

I think I will avoid using 'on_event' in future.

‘SQLMODEL learn’ detailed instruction helps me study many much.(Although it is still quite difficult for me as a beginner.)
Tutorial - User Guide