Fijne functies

def sq(x):
    """Returns Square of the argument

    :param x: The value to square
    :type x: int, float
    :rtype: int, float
    """
    return x * x

def interp(low, hi, fraction):
    """Calulcates fraction

    :param low: lowest value
    :param hi: highest value
    :param fraction: fraction 
    :type low, hi, fraction: int, float
    :rtype: float
    """

    return low + (hi - low) * fraction 

def checkends(s):
    return s[0] == s[-1] 

def flipside(s):
    halfLength = int(len(s)/2)
    return s[halfLength :] + s[:halfLength]

def  convert_from_seconds(s):
    days = int(s/86400)
    left = s % 86400
    hours = int(left/3600)
    left = left % 3600
    minutes = int(left/60)
    seconds = left % 60
    return [days, hours, minutes, seconds]