[QUESTION] Return lists

Hi there!

First of all, gerat project! Thank You for sharing it!

i’m a somewhat a beginner, i’d like some help if you guys don’t mind. (I couldn’t find another forum for questions)

I’ve managed to read a list of objects inside a json, by passing the body like this:

[
  {
    "name": "Item name example 1",
    "price": 100,
    "is_offer": true
  },
  {
    "name": "Item name example 2",
    "price": 100,
    "is_offer": true
  },
  {
    "name": "Item name example 3",
    "price": 100,
    "is_offer": true
  }
]

The objective of my micro example is to receive a list of Items (the same base class of the API example), do some processing (change price value by a fixed factor) and return that altered list.

this works:

@app.put("/items/{item_id}")
def create_item(item_id: int, items: List[Item]):    
    return {"total" : len(items)}

and i can iterate trough the list with

for item in items:

but when i try to return the list with

return {items}

i get “TypeError: unhashable type: ‘list’” error.

is there a simple way to return the list? Or i’ll need to create the return string manually?

[tiangolo]

Awesome @DaviOtero ! 🎉

---

As always, thanks @euri10 ! 👏 🌮 🍰

[euri10]

You may (or I may misunderstand what you want to do) be mixing response_model and query parameters

• to return a list you should have a response_model in the route @app.put("/items/{item_id}", response_model=List[Item])
• the items: List[Item] part means you want a list of items in the query passed in the put
• the curly braces around items most likely cast items to a set (not sure about that)