Simple exercise

Thu Mar 10 19:05:52 EST 2016

On 10/03/2016 09:02, Rodrick Brown wrote:
>>From the following input
>> 9
> BANANA FRIES 12
> POTATO CHIPS 30
> APPLE JUICE 10
> CANDY 5
> APPLE JUICE 10
> CANDY 5
> CANDY 5
> CANDY 5
> POTATO CHIPS 30
>> I'm expecting the following output
> BANANA FRIES 12
> POTATO CHIPS 60
> APPLE JUICE 20
> CANDY 20

Here's a rather un-Pythonic and clunky version. But it gives the 
expected results. (I've dispensed with file input, but that can easily 
be added back.)
def last(a):
 return a[-1]
def init(a): # all except last element
 return a[0:len(a)-1]
data =["BANANA FRIES 12", # 1+ items/line, last must be numeric
 "POTATO CHIPS 30",
 "APPLE JUICE 10",
 "CANDY 5",
 "APPLE JUICE 10",
 "CANDY 5",
 "CANDY 5",
 "CANDY 5",
 "POTATO CHIPS 30"]
names = [] # serve as key/value sets
totals = []
for line in data: # banana fries 12
 parts = line.split(" ") # ['banana','fries','12']
 value = int(last(parts)) # 12
 name = " ".join(init(parts)) # 'banana fries'
 try:
 n = names.index(name) # update existing entry
 totals[n] += value
 except:
 names.append(name) # new entry
 totals.append(value)
for i in range(len(names)):
 print (names[i],totals[i])
-- 
Bartc