Python字典判空方式

使用in关键字

任务：将原字典列表转换为一个字典，相同关键字的值累加

origin_list = [{"Tom": 12}, {"Tom": 13}, {"Alice": 25}, {"Alice": 13}]

result_dict = {}
for item in origin_list:
    for key, value in item.items():
        if key in result_dict:
            result_dict[key] += value
        else:
            result_dict[key] = value

print(result_dict)

使用try except

origin_list = [{"Tom": 12}, {"Tom": 13}, {"Alice": 25}, {"Alice": 13}]

result_dict = {}
for item in origin_list:
    for key, value in item.items():
        try:
            result_dict[key] += value
        except KeyError:
            result_dict[key] = value

print(result_dict)