如何获得与条件在Python中元素列表的总和？

Question

如何在python中获取条件元素列表的总和？

a = [{ "a" : 1 }, {"a" : 1}, { "a" : 3 }, { "a" : 4 }, { "a" : 5 }, { "a" : 7 }] 

def test(d): 
    cnt = 0 
    for row in d: 
     if row["a"] > 1: cnt = cnt + 1 
    return cnt 


    my variant: 

    rr = len([ 1 for row in a if row["a"] > 1 ]) 

Answer 1

>>> a = [{ "a" : 1 }, {"a" : 1}, { "a" : 3 }, { "a" : 4 }, { "a" : 5 }, { "a" : 7 }]  
>>> sum([row['a'] for row in a if row['a'] > 1]) 
19