import os.path

#get filename and validate it
def get_filename():
    filename = input("Please enter filename: ")
    while not os.path.exists(filename):
        print("That file does not exist.")
        filename = input("Please enter filename: ")
    return filename


#read file contents
def read_file(filename):
    infile = open(filename, 'r')
    data = infile.readlines()
    infile.close()
    data = [float(v) for v in data]
    return data


#calculate total sales (and average?)
def cal_total_sales_avg(daily_sales):
    total = sum(daily_sales)
    avg = total / len(daily_sales)
    return total, avg

#display total & average sales
def display_total_avg(total, average):
    total = format(total, '.2f')
    average = format(average, '.2f')

    print('The total is: $', total, sep='')
    print('The average per day is: $', average, sep='')

'''
#alternate solution for: display total & average sales
def format_money(amount):
    return '$'+format(amount, '2f')

print('The total is: ', format_money(total), sep='')
print('The average per day is: ', format_money(average), sep='')
'''




filename = get_filename()
daily_sales_amounts = read_file(filename)
total, avg = cal_total_sales_avg(daily_sales_amounts)
display_total_avg(total, avg)


#amounts = cal_total_sales_avg(daily_sales_amounts)
#display_total_avg(*amounts)