HTTP Methods 📡

HTTP methods define what action an API endpoint should perform. The main methods are GET, POST, PUT, PATCH, and DELETE.

GET - Retrieve Data

Fetch data without modifying anything.

@app.get("/users/{user_id}")
async def get_user(user_id: int):
    return {"id": user_id, "name": "John"}

Usage:

• Retrieve a user: `GET /users/123`

• List all users: `GET /users`

• Filter data: `GET /users?status=active`

POST - Create Data

Create a new resource.

@app.post("/users")
async def create_user(user: User):
    new_id = db.insert(user)
    return {"id": new_id, **user.dict()}

Request:

{"name": "Jane", "email": "jane@example.com"}

Response (201 Created):

{"id": 2, "name": "Jane", "email": "jane@example.com"}

PUT - Replace Data

Replace an entire resource.

@app.put("/users/{user_id}")
async def update_user(user_id: int, user: User):
    db.replace(user_id, user)
    return {"id": user_id, **user.dict()}

Must provide complete object.

PATCH - Partial Update

Update only specific fields.

@app.patch("/users/{user_id}")
async def patch_user(user_id: int, update: UserUpdate):
    db.patch(user_id, update)
    return db.get(user_id)

Only include fields to change.

DELETE - Remove Data

Delete a resource.

@app.delete("/users/{user_id}")
async def delete_user(user_id: int):
    db.delete(user_id)
    return {"deleted": True}

Response (204 No Content):

Empty response with status 204.

Method Summary

Real API Example

@app.get("/products")
async def list_products():
    return db.list()

@app.post("/products")
async def create_product(product: Product):
    return db.create(product)

@app.get("/products/{product_id}")
async def get_product(product_id: int):
    return db.get(product_id)

@app.put("/products/{product_id}")
async def replace_product(product_id: int, product: Product):
    return db.replace(product_id, product)

@app.delete("/products/{product_id}")
async def delete_product(product_id: int):
    db.delete(product_id)
    return None

🔑 Key Takeaways

• ✅ GET retrieves data

• ✅ POST creates new resources

• ✅ PUT replaces entire resources

• ✅ PATCH partially updates

• ✅ DELETE removes resources

• ✅ Each method has a specific purpose