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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def calcDeviationLimits(value, tolerance, mode):
 """Returns the upper and lower deviation limits for a value and a given tolerance, either as relative or a absolute difference. :param value: can be a single value or a list of values if a list of values is given, the minimal value will be used to calculate the lower limit and the maximum value to calculate the upper limit :param tolerance: a number used to calculate the limits :param mode: either ``absolute`` or ``relative``, specifies how the ``tolerance`` should be applied to the ``value``. """

    values = toList(value)
    if mode == 'relative':
        lowerLimit = min(values) * (1 - tolerance)
        upperLimit = max(values) * (1 + tolerance)
    elif mode == 'absolute':
        lowerLimit = min(values) - tolerance
        upperLimit = max(values) + tolerance
    else:
        raise Exception('mode %s not specified' %(filepath, ))
    return lowerLimit, upperLimit