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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 get_num_days_required(offset, period='d', perc_required=0.90):
 """ Estimates the number of days required to assume that data is OK. Helper function used to determine if there are enough "good" data days over a given period. Args: * offset (DateOffset):
 Offset (lookback) period. * period (str):
 Period string. * perc_required (float):
 percentage of number of days expected required. """

    x = pd.to_datetime('2010-01-01')
    delta = x - (x - offset)
    # convert to 'trading days' - rough guestimate
    days = delta.days * 0.69

    if period == 'd':
        req = days * perc_required
    elif period == 'm':
        req = (days / 20) * perc_required
    elif period == 'y':
        req = (days / 252) * perc_required
    else:
        raise NotImplementedError(
            'period not supported. Supported periods are d, m, y')

    return req