Get a running total from a list

Question

I\'m reading in items:

for line in sys.stdin:
    line = line.strip()
    data = line.split(\"-\")

If I print data as it is read,

Answer 1

Use a collections.Counter() to count the occurrences:

import collections

lines = [['Adam', '5'],
         ['Peter', '7'],
         ['Adam', '8'],
         ['Lucy', '2'],
         ['Peter', '4']]

counter = collections.Counter()
for data in lines:
    counter[data[0]] += int(data[1])

print(counter)

You'll get:

Counter({'Adam': 13, 'Peter': 11, 'Lucy': 2})