Python - sum values in dictionary

Question

I have got pretty simple list:

example_list = [
    {\'points\': 400, \'gold\': 2480},
    {\'points\': 100, \'gold\': 610},
    {\'points\': 100, \'gold\':          


        

Answer 1

If you're memory conscious:

sum(item['gold'] for item in example_list)

If you're extremely time conscious:

sum([item['gold'] for item in example_list])

In most cases just use the generator expression, as the performance increase is only noticeable on a very large dataset/very hot code path.

See this answer for an explanation of why you should avoid using map.

See this answer for some real-world timing comparisons of list comprehension vs generator expressions.