模仿没有像预期的那样工作(Django)

我有这样的代码:

//app1.service.py

database = {
    1: "Alice",
    2: "Bob",
    3: "Charlie"
}


def get_user_from_db(user_id):
    return database.get(user_id)

//app1.tests.test_service.py

import pytest
from unittest import mock

from app1.service import get_user_from_db


@mock.patch("app1.service.get_user_from_db")
def test_get_user_from_db(mock_get_user_from_db):
    mock_get_user_from_db.return_value = "Mocked Alice"
    username = get_user_from_db(1)  # If I change it to mock_get_user_from_db(1) everything works fine
    assert username == "Mocked Alice"

当我在命令行中运行‘pytest’时，我得到以下结果:

E       AssertionError: assert 'Alice' == 'Mocked Alice'
E         - Mocked Alice
E         + Alice

在我正在观看的教程中，get_user_from_db(1)返回"Mocked Alice",，但在我的本地机器中，它只返回"Alice".当我使用它时，它工作得很好

username = mock_get_user_from_db(1)

而不是

username = get_user_from_db(1)

Question: It this the expected behaviour that username = get_user_from*db(1) returns "Alice" in my case?(在YouTube视频中，它返回"被嘲笑的爱丽丝")or am I just doing something wrong?