Sum numbers by letter in list of tuples

Question

I have a list of tuples:

[ (\'A\',100), (\'B\',50), (\'A\',50), (\'B\',20), (\'C\',10) ]

I am trying to sum up all numbers that have the s

Answer 1

A simpler approach

x = [('A',100),('B',50),('A',50),('B',20),('C',10)]
y = {}
for _tuple in x:
    if _tuple[0] in y:
        y[_tuple[0]] += _tuple[1]
    else:
        y[_tuple[0]] = _tuple[1]
print [(k,v) for k,v in y.iteritems()]