Accumulating prices for a time period?

Question

I have this function and what I want is the if-statement to be run over and over, accumulating a a price until the conditions are no longer met. Once met, do some other calculations in the else, reset the values (I tried with = 0) and return a value. But for some reason it doesn't do the right calculation and gives out nonsense.

cur_time = dt.datetime.now()
future_time = cur_time + 100

def A(cur_time, price):
    if int(future_time) > int(cur_time): 
        price_acum += (float(price))
    else:
        avg_price = price_acum/100
        print(avg_price )
        future_time = cur_time + 100
    return (avg_price )