Example of an estimation calculator for Transferwise transfers

calculate_estimate.py

def calculate_delivery_estimate(todays_date, current_weekday):
    '''Calculates a delivery estimate based on today's date and day of week'''
    
    # average time in minutes that it took for a transfer complete 
    # when it was created on that day of the week
    # this data only represents Payment Type A in a single currency_corridor.
    # it also already has total transfer time delivery outliers removed.
    weekday_delivery_avg_minutes = {
        'Fri': 5677.73,
        'Mon': 2918.34,
        'Sat': 4619.68,
        'Sun': 2963.84,
        'Thu': 5355.96,
        'Tue': 3050.19,
        'Wed': 3401.28}

    # convert a minute timestamp to number-of-days (use to produce estimate on front-end for user)
    def minutes_to_day_converter(minutes):
        return round(minutes/24/60, 1)

    # hardcode some holidays as strings for demonstration
    holidays = ['12/25/18', '01/21/18']

    # get the expected average from today's data
    todays_average = weekday_averages[current_weekday]
    
    # get the value in hours that would be displayed in UI
    ui_hour_value = minutes_to_day_converter(todays_average)

    # mostly for demonstrative purposes
    def generate_ui_message(ui_hour_value, is_holiday=False):
        '''Generates message for UI. If it is a holiday, use a custom note.'''
        
        if is_holiday:
         return "NOTE: It is currently a holiday and your transfer may take longer than usual.{}On non holidays, this transfer usually takes less than {} days" .format("\n", ui_hour_value)

        return "Your transfer should arrive in less than {} days".format(ui_hour_value)

    if not todays_date in holidays:
        # can return basic message
        print(generate_ui_message(ui_hour_value))
    else:
        # today's date is in a holiday range. therefore return some message like "unable to give accurate estimate due to holidays"
        print(generate_ui_message(ui_hour_value, is_holiday=True))
        
# test output of function with some values:
calculate_delivery_estimate('12/25/18', 'Tue')

calculate_delivery_estimate('12/08/18', 'Sat')