taktik

var driver = new RemoteWebDriver(new Uri("http://localhost:4444/wd/hub"), DesiredCapabilities.Firefox());

@pytest.mark.parametrize('number1, number2', [
    ({1: 2}, {2: 3})
])
def test_01(driver, number1, number2):
    pass

file = open("d:/login_pass_file.txt", 'r')
login_pass_dict = dict()
for x in [line.strip().split(':') for line in file]:
    login_pass_dict.update({x[0]: x[1]})

for login, password in login_pass_dict.items():
    # тут твой код