def is_approx(first, second, tolerance=0.0001):
    """
    Test if two values are approximately the same.

    Keyword arguments:
    tolerance -- cutoff for allowed difference (default 0.0001)

    >>> is_approx(0.0000, 0.0001)
    False

    >>> is_approx(0.0000, 0.00009)
    True
    """
    if (first + tolerance) > second and (first - tolerance) < second:
        return True
    else:
        return False