summing only the numbers contained in a list

Question

Give a method that sums all the numbers in a list. The method should be able to skip elements that are not numbers. So, sum([1, 2, 3]) should be

Answer 1

use filter and isinstance like this

>>> test = [1,2,3,4,5,6,"A","B"]
>>> sum(filter(lambda x:isinstance(x,int),test))
21
>>>