Sum list based on function
Python, Math, List · Nov 2, 2020
Calculates the sum of a list, after mapping each element to a value using the provided function.
- Use
map()withfnto map each element to a value using the provided function. - Use
sum()to return the sum of the values.
def sum_by(lst, fn):
return sum(map(fn, lst))sum_by([{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }], lambda v : v['n']) # 20
