python - Find duplicates, add to variable and remove -

i have script writes sales values separate lines in file , ultimate goal save data database. problem i'm running there duplicate entries same sales person, date, product, price , quantity.

my code written file:

john 07-15-2016 tool belt $100 2 sara 07-15-2016 hammer $100 3 john 07-15-2016 tool belt $100 2 john 07-15-2016 tool belt $100 2 sara 07-15-2016 hammer $100 3 

how remove duplicates , add them together? i.e. output be:

john 07-15-2016 tool belt $100 6 sara 07-15-2016 hammer $100 6 

i've used counter doesn't catch multiple instances, nor can find way add 2 together.

any appreciated.

script:

for line in s:         var = re.compile(r'(\$)',re.m)         line = re.sub(var, "", line)         var = re.compile(r'(\,)',re.m)         line = re.sub(var, "", line)         line = line.rstrip('\n')         line = line.split("|")         if line[0] != '':             salesperson = str(salesperson)             date = dt.now()             t = line[0].split()             print t             t = str(t[0])             try:                 s = dt.strptime(t, "%h:%m:%s")             except:                 s = dt.strptime(t, "%h:%m")             s = s.time()             date = dt.combine(date, s)             date = str(date)             price = line[1]             quantity = line[2]         fn.write("%s %s %s %s \n" % (salesperson, date, price, quantity))     fn.close() 

sample.csv

john 07-15-2016 tool belt $100 2 sara 07-15-2016 hammer $100 3 john 07-15-2016 tool belt $100 2 john 07-15-2016 tool belt $100 2 sara 07-15-2016 hammer $100 3 

test.py

with open("sample.csv") inputs:     mydict = dict()     line in inputs:         elements = line.strip().split()         key = " ".join(elements[0: len(elements) - 1])          mydict[key] = mydict.get(key, 0) + int(elements[-1])      # iterate dictionary , print out result     key, value in mydict.iteritems():         print "{0} {1}".format(key, value) 

i use dictionary, split each line , use first len(elements) - 1 elements key, , increase last elements when iterate lines.

mydict.get(key, 0) returns value if key exist in dictionary, otherwise return value 0

result: python2.7 test.py

sara 07-15-2016 hammer $100 6 john 07-15-2016 tool belt $100 6 

therefore in case need:

elements = line.strip().split() key = " ".join(elements[0: len(elements) - 1])  mydict[key] = mydict.get(key, 0) + int(elements[-1])