"lists of Submodels" in Fastapi - fastapi

Question

How can I get the key and value in the list of submodel?
Below is the code that I made,
from fastapi import FastAPI
from pydantic import BaseModel
app = FastAPI()
class Image(BaseModel):
url: str
name: str
class Item(BaseModel):
name: str
price: float
tax: list[float]
image: list[Image]
#app.post("/items")
def update_item(item: Item):
return item.image
Send data as a request body
{
"name": "item_name",
"price": 120.99,
"tax": [
1.99, 2.99
],
"image": [
{
"url": "www.naver.com",
"name": "naver"
},
{
"url": "www.google.com",
"name": "google"
}
]
}
And I can send the response as below.
[
{
"url": "www.stackoverflow.com",
"name": "stackoverflow"
},
{
"url": "www.google.com",
"name": "google"
}
]
How to get the key(`"url") and value("google") from the List of Image model?
I newly start to learn fastapi, and I thought that I can get the values in the list of Image model through item.image.url or something like that, likewise item.name or item.tax, but it didn't work.
To explain the problem in more detail, I would like to check there is a value google in Image model first, and if it exists then get the value of url key.
I tried as below,
#app.post("/items")
def update_item(item: Item):
url = [i['url'] for i in item.image if i['name'] == 'naver']
return url
but it returns
TypeError: 'Image' object is not subscriptable

Answer 1

You used i['url'] which is how you would approach a dictionary. However, this is a pydantic model, with properties. You were quite close, but you should replace i['url'] with i.url (and also i.name a little further in your code). So, like this:
#app.post("/items")
def update_item(item: Item):
url = [i.url for i in item.image if i.name == 'naver']
if len(url) == 1:
return url[0]
return None
Note that variable url a list, you should check if the list is empty or not before trying to get the first element (which would be the URL of the image named 'never'). The above would return None if no Images with name 'naver' is found.