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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 load_factor(ts, resolution=None, norm=None):
 """ Calculate the ratio of input vs. norm over a given interval. Parameters ts : pandas.Series timeseries resolution : str, optional interval over which to calculate the ratio default: resolution of the input timeseries norm : int | float, optional denominator of the ratio default: the maximum of the input timeseries Returns ------- pandas.Series """

    if norm is None:
        norm = ts.max()

    if resolution is not None:
        ts = ts.resample(rule=resolution).mean()

    lf = ts / norm

    return lf