gistfile1.py

import random

import pytest

@pytest.fixture
def random_number(request):
    # You can set attrs on the py.test Config object whenever you want
    # Here works, as well as any pytest hook that accepts the config arg
    request.session.config.random_number = random.randint(0, 10000)

def test_random_number(random_number, request):
    # And then they're in the config, which will be passed the the
    # subprocess workers
    assert request.session.config.random_number