如何从另一个字典中的字典中添加值？

def add_values_from_dict(target_dict, source_dict):
    for key, value in target_dict.items():
        if key in source_dict:
            target_dict[key] += source_dict[key]
        else:
            target_dict[key] = source_dict[key]

# 示例用法
target_dict = {"a": {"x": 1, "y": 2}, "b": {"x": 3, "y": 4}}
source_dict = {"a": {"x": 5, "y": 6}, "b": {"x": 7, "y": 8}}

add_values_from_dict(target_dict, source_dict)
print(target_dict)

{"a": {"x": 6, "y": 8}, "b": {"x": 10, "y": 12}}