Gemini 2.0: use a list of Pydantic objects at response schema

Gemini API
3

Pydantic actually works with Gemini 2.0 (response_schema). Please check the code below which works for me. The error message is not coming from Gemini 2.0.

import os

from google import genai
from google.genai.types import GenerateContentConfig

from PIL import Image
from pydantic import BaseModel

os.environ["API_KEY"] = <YOUR_API_KEY>

client = genai.Client(api_key=os.environ["API_KEY"])


image = Image.open(SOME_IMAGE_PATH)
prompt = "Detect objects box 2d."

class Object(BaseModel):
    label: str
    box_2d: list[int]
    
response = client.models.generate_content(
    model="gemini-2.0-flash-exp",
    contents=[image, prompt],
    config=GenerateContentConfig(
        response_mime_type="application/json",
        response_schema=Object,
    ),
)

print(response.text)