✨ Add docs and tests for Python 3.9 and Python 3.10 (#3712)

Co-authored-by: Thomas Grainger <tagrain@gmail.com>

docs_src/extra_models/tutorial002_py310.py

@@ -0,0 +1,39 @@
+from fastapi import FastAPI
+from pydantic import BaseModel, EmailStr
+
+app = FastAPI()
+
+
+class UserBase(BaseModel):
+    username: str
+    email: EmailStr
+    full_name: str | None = None
+
+
+class UserIn(UserBase):
+    password: str
+
+
+class UserOut(UserBase):
+    pass
+
+
+class UserInDB(UserBase):
+    hashed_password: str
+
+
+def fake_password_hasher(raw_password: str):
+    return "supersecret" + raw_password
+
+
+def fake_save_user(user_in: UserIn):
+    hashed_password = fake_password_hasher(user_in.password)
+    user_in_db = UserInDB(**user_in.dict(), hashed_password=hashed_password)
+    print("User saved! ..not really")
+    return user_in_db
+
+
+@app.post("/user/", response_model=UserOut)
+async def create_user(user_in: UserIn):
+    user_saved = fake_save_user(user_in)
+    return user_saved