求一个特殊的python函数算法

有两个字典数组分别如下
a_l = [{'a': 1, 'b': 2, 'c': 3, 'os': "linux"}, {'a': 31, 'b': 33, 'c': 34, 'os': "windows"},{'a': 21, 'b': 23, 'c': 24, 'os': "unix"}]
b_l = [{'a': 11, 'b': 21, 'c': 31, 'os': "linux"}, {'a': 31, 'b': 53, 'c': 44, 'os': "unix"}, {'a': 21, 'b': 23, 'c': 24, 'os': "windows"}]

需要写一个函数，计算出 result = [{'a': 12, 'b': 23, 'c': 34, 'os': "linux"}, {'a': 52, 'b': 56, 'c': 58, 'os': "windows"}, {'a': 52, 'b': 76, 'c': 68, 'os': "unix"}]

a_l = [{'a': 1, 'b': 2, 'c': 3, 'os': "linux"},
       {'a': 31, 'b': 33, 'c': 34, 'os': "windows"},
       {'a': 21, 'b': 23, 'c': 24, 'os': "unix"}]
b_l = [{'a': 11, 'b': 21, 'c': 31, 'os': "linux"},
       {'a': 31, 'b': 53, 'c': 44, 'os': "unix"},
       {'a': 21, 'b': 23, 'c': 24, 'os': "windows"}]

res = []

for i in a_l:
    d = {}
    for j in b_l:
        if j.get('os') == i['os']:            
            d['a'] = j.get('a') + i['a']
            d['b'] = j.get('b') + i['b']
            d['c'] = j.get('c') + i['c']
            d['os'] = i['os']
            res.append(d)
print(res)
"""--result
[{'a': 12, 'b': 23, 'c': 34, 'os': 'linux'}, {'a': 52, 'b': 56, 'c': 58, 'os': 'windows'}, {'a': 52, 'b': 76, 'c': 68, 'os': 'unix'}]

"""