def traffic_light(load):
    """Takes a floating point number load.
    The function should return the string:

    "green" for values of load below 0.7
    "amber" for values of load equal to or greater than 0.7 but smaller than 0.9
    "red" for values of load equal to 0.9 or greater than 0.9"""

    if load < 0.7:
        return "green"
    elif 0.7 <= load < 0.9:
        return "amber"
    elif load >= 0.9:
        return "red"