# find the total order size for different products if the orders are
# specified as a line with a product name, and an optional comma and number
# if the comma and number are missing, or the number is missing or not a
# valid number, assume an order of 1

def orderTotals(src,dst) :
    s = open(src,"r")
    d = open(dst,"w")
    # put the orders in a dictionary
    # dictionaries are efficient for lookup, and the values are mutable
    # so as we get new orders we can update it
    # if this were written in 2016 and not 1992, we would not read from a
    # file, but would get orders live from the internet
    # in the live case, it is really important that we read the file line
    # by line, and using a dictionary lets us print a summary every hour, etc.
    orders = {}
    # this is new way of going through the lines in a file
    # when we use a for like this, the .readline() is hidden
    # just like the indexing into a list is also hidden when using a for
    for line in s :
        # we often use comma, space of tab separated files, and there is
        # a convenient way of turning each line into a list
        fields = line.split(',')
        # a "blank line" is not an empty string, it has a return '\n'
        # this will give us an empty first component, as would a line
        # ",anything", but in either case we can ignore this line
        if fields[0] != '' or fields[0] = '\n':
            # precondition:  fields[0] is not empty
            # now check for there being a field which could be a number
            if len(fields) >= 2 :
                # and try to get a number out of it, but if that fails...
                try :
                    numOrdered = int(fields[1])
                except :
                    # assume an order of 1
                    numOrdered = 1
            else :
                # if there is no second field, also assume an order of 1
                numOrdered = 1
            # now check whether this thing has been ordered before, in
            # which case add to the current order, otherwise start counting
            if fields[0] in orders :
                orders[fields[0]] = numOrdered + orders[fields[0]]
            else :
                orders[fields[0]] = numOrdered

    # finally, we need to print out the total orders
    for item in orders :
        # note that try to avoid really dumb plurals, but allow somewhat
        # silly ones like grasss and octupuss
        if orders[item] > 1 :
            plural = "s"
        else :
            plural = ""
        d.write(str(orders[item]) + " " + item + plural + " ordered")
    # don't forget to put your toys away
    d.close()
    s.close()