Does @app.delete in FastAPI actually delete anything?

2025-07-09 · fastapi · python

Learning FastAPI, I had two questions: after @app.delete runs, has the resource really been “deleted”? And can the same function still add new content afterwards?

What @app.delete is

• @app.delete(...) is a FastAPI decorator that declares which function handles HTTP DELETE requests for a path.
• It only binds the path to the function; what happens inside is entirely up to you.
• It does not delete anything by itself.

So @app.delete is not an automatic delete: the deletion has to be written in the function body, for example del students[student_id].

Can you add data after deleting?

Yes. The handler can do anything: write a log, append to another data structure, call an external system, or even put the deleted item back (rare).

Example: log the deleted record

@app.delete("/delete-student/{student_id}")
def delete_student(student_id: int):
    if student_id not in students:
        raise HTTPException(status_code=404, detail="Student does not exist")

    # get the record before deleting it
    deleted_student = students[student_id]

    # delete the student
    del students[student_id]

    # keep a copy in a separate "deleted students" dictionary
    deleted_log[student_id] = deleted_student

    return {"message": "Student deleted and logged successfully"}

The function first removes the original data and then adds new content (deleted_log); the two do not conflict.

Why it is designed this way

FastAPI’s idea is: you control the logic, the framework provides the interface. Unlike Django’s generic views, it does not apply default behaviour to your models for you. That gives you flexibility, at the cost of writing the logic yourself.

Summary