Que es lo que sucede cuando <code>127.0.0.1:8000</code> se queda cargando infinitamente? Me pasa continuamente, hay un error en el codigo?

Si, es exactamente la misma que he puesto :/

Si estás iniciando bien el servicio?

uvicorn main:app --reload

Este es mi codigo

#Python
from typing import Optional
from enum import Enum

#Pydantic
from pydantic import BaseModel
from pydantic import Field
from pydantic.networks import EmailStr, HttpUrl
from pydantic.types import PaymentCardNumber

#FastAPI
from fastapi import FastAPI
from fastapi import Body, Query, Path
app = FastAPI()

#Models

class CustomerSeller(Enum):
    customer = "customer"
    seller = "seller"

class HairColor(Enum): 
    white = "white"
    brown = "brown"
    black = "black"
    blonde = "blonde"
    red = "red"
    
class location(BaseModel):
    city : str = Field(
        ...,
        min_length = 1,
        max_length = 150,
    )
    state: str = Field(
        ...,
        min_length = 1,
        max_length = 150,
    )
    country: str = Field(
        ...,
        min_length = 1,
        max_length = 150,
    )
    class Config:
        schema_extra = {
            "example" : {
                "city" : "Bello",
                "state" : "Antioquia",
                "country" : "Colombia"
            }
        }

class Person(BaseModel):
    first_name : str = Field(
        ..., 
        min_length = 1,
        max_length = 50,
    )
    last_name : str = Field(
        ..., 
        min_length = 1,
        max_length = 50,
    )
    age: int = Field(
        ...,
        gt = 0,
        le = 115,
    )
    email : EmailStr = Field(...)
    web_site : Optional[HttpUrl] = Field(default = None)
    customer_seller : Optional[CustomerSeller] = Field(default = "customer")
    hair_color : Optional[HairColor] = Field(default = None)
    is_married : Optional[bool] = Field(defauld = None)
    password : str = Field(..., min_length = 8 )

    #DATOS DE PRUEBA
    class Config:
        schema_extra = {
            "example" : {
                "first_name" : "Mateo",
                "last_name" : "Echavarria",
                "age" : 18,
                "email" : "echavarria.0042@gmail.com",
                "web_site" : "https://teoechavarria.github.io/",
                "customer_seller" : "customer",
                "hair_color" : "brown",
                "is_maried" : False
            }
        }

@app.get("/")
def home():
    return {"Hello": "World"}

# Request and Pesponse

@app.post("/person/new")
                                #Obligatorio el (...)
def create_person(person: Person = Body(...)):
    return person

#Validaciones: Query Parameters
@app.get("/person/detail")
def show_person(
    name: Optional[str] = Query(
        None, 
        min_length = 1, 
        max_length=50,
        title = "Person Name",
        description = "This is the person name. It´s between 1 and 50 characters",
        example = "Rocio"
        ),
    age : str = Query(
        ...,
        title = "Person Age",
        description = "This is the person age. It´s required",
        example = 48
        )
):
    return {name : age}

#Validaciones: Path Parameters

@app.get("/person/detail/{person_id}")
def show_person(
    person_id : int = Path(
        ..., 
        gt=0,
        title = "Person Id",
        description = "This is the Person Id.",
        example = 123
        )
):  
    return {person_id: "It exists"}

#Validaciones: Request Body

@app.put("/person/{person_id}")
def update_person(
    person_id: int = Path(
        ...,
        title = "Person ID",
        description = "This is the person ID",
        gt = 0,
        example = 123
    ),
    person : Person = Body(...),
    #location: location = Body(...)
):
    #results = person.dict()
    #results.update(location.dict())
    #return results
    return person

@app.post("/person/{person_id}/buy")
def BuyWebSide(
    person_id: int = Path(
        ...,
        title = "Person ID",
        description = "This is the person ID",
        gt = 0
    ),
    URLtoBuy : HttpUrl = Path(...),
    value : float = Path(
        ..., 
        gt=0,
        title = "Value Website",
        description = "This is the value of the web site you have registered"
    ),
    PayCard : PaymentCardNumber = Path(...),
    person : Person = Body(...)
):