Patching in Python with pytest using monkeypatch and requests_mock

patch.py

import requests
API_URL = "https://example.com"  # often imported from settings

#
# Code
#

def get_user_with_org(id: str):
    """Gets a User object with the User's Organisation"""

    # fetch the data (side effect)
    user = requests.get(f'{API_URL}/user/{id}').json()
    org_id = user['org_id']
    organisation = requests.get(f'{API_URL}/organisation/{org_id}').json()

    return {'user': user, 'organisation': organisation}

#
# Tests: pytest monkeypatch
#

from unittest.mock import MagicMock

def test_get_user_with_org(monkeypatch):
    """Test getting a user + organisation by mocking the side effect"""
    monkeypatch.setattr(requests, "get", lambda _: MagicMock())

    result = get_user_with_org("test-id")

    assert 'organisation' in result
    assert 'user' in result
    assert result['user']['org_id'].__str__.called

#
# Tests: pytest + requests_mock
#

import requests_mock

def test_get_user_with_org2(requests_mock):
    """Test getting a user + organisation by mocking with requests_mock library"""

    requests_mock.get(
        f'{API_URL}/user/user-1',
        json={'id': 'user-1', 'name': 'Test User', 'org_id': 'org-1'}
    )

    requests_mock.get(
        f'{API_URL}/organisation/org-1',
        json={'id': 'org-1', 'name': 'Test Org'}
    )

    result = get_user_with_org('user-1')

    assert 'organisation' in result
    assert 'user' in result
    assert result['user']['name'] == 'Test User'
    assert result['organisation']['name'] == 'Test Org'