💭 Handling Errors - FastAPI
===========================

!https://fastapi.tiangolo.com/tutorial/handling-errors/

Date: April 30, 2024

Handling Errors - FastAPI
 FastAPI framework, high performance, easy to learn, fast to code, ready for production
 fastapi.tiangolo.com [1]

This page shows how to customize your fastapi errors. I found this very useful to setup common templates so that I can return the same 404's both programatically and by default, so it all looks the same to the end user.

``` python
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse

class UnicornException(Exception):
 def __init__(self, name: str):
 self.name = name

app = FastAPI()

@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
 return JSONResponse(
 status_code=418,
 content={"message": f"Oops! {exc.name} did something. There goes a rainbow..."},
 )

@app.get("/unicorns/{name}")
async def read_unicorn(name: str):
 if name == "yolo":
 raise UnicornException(name=name)
 return {"unicorn_name": name}
```

---

This post sat in draft for months. I stumbled upon it again and found great success returning good error messages based on user preferences. the default remains json, but if a user requests `text/html` it will be an html response, and text for `application/rtf` or `text/plain`

!!! note

 This post is a thought [2]. It's a short note that I make
 about someone else's content online #thoughts [3]

References:
[1]: https://fastapi.tiangolo.com/tutorial/handling-errors/
[2]: /thoughts/
[3]: /tags/thoughts/