pytest with ducktyping

do.py

import requests
import xml.etree.ElementTree as ET

def get_current_weather(uri: str, client = requests) -> str:
    result = client.get(uri)
    weather = ET.ElementTree(ET.fromstring(result.text)).getroot().findall("./weather")[0].text
    return weather



if __name__ == '__main__':
    print(get_current_weather("https://w1.weather.gov/xml/current_obs/KMYF.xml", requests))

test_do.py

import do


def test_get_current_weather():
    assert do.get_current_weather(
        "https://w1.weather.gov/xml/current_obs/KMYF.xml", MockRequestsClient) == "foobar"


class MockRequestsClient:

    def get(self):
        return MockClientResponse("<current_observation><weather>foobar</weather></current_observation>")


class MockClientResponse:

    def __init__(self, get_response):
        self.text = get_response