client.py

class APIKeyMixin:
    @classmethod
    def from_env(cls: Type[T], livemode: bool = False) -> T:
        key_id = os.environ.get("API_KEY_ID", "")
        secret_key = os.environ.get("API_SECRET_KEY", "")
        if not key_id or not secret_key:
            raise RuntimeError(
                "Environment variables `API_KEY_ID` and `API_SECRET_KEY` need to be defined."
            )
        return cls(key_id, secret_key, livemode=livemode)

    def __init__(self, key_id: str, secret_key: str, *, livemode: bool = False):
        self.key_id = key_id
        self.secret_key = secret_key
        self.livemode = livemode

conftest.py

# run with `APCA_API_SECRET_KEY="123" APCA_API_KEY_ID="ABC" PYTHONPATH=. poetry run pytest -vv --run-api-tests`

import pytest
from example import APIClient


def pytest_addoption(parser):
    parser.addoption("--run-api-tests", action="store_true", help="run live API tests")


@pytest.fixture(scope="session")
def api_client():
    return APIClient.from_env(livemode=False)


def pytest_generate_tests(metafunc):
    if "api_client" in metafunc.fixturenames:
        if not metafunc.config.getoption("run_api_tests"):
            pytest.skip("Skipping API tests")

test_api.py

# run with `API_SECRET_KEY="123" API_KEY_ID="ABC" PYTHONPATH=. poetry run pytest -vv --run-api-tests`


def test_list_accounts(api_client):
    resp = api_client.accounts.list()
    assert isinstance(resp, list)