在 Python 中对 json 对象中的值求和

Question

我有两个 JSON 对象。我想合并它们，但是只要键相同，就应该对字段 obj_count 求和。在 python 中有什么办法解决它吗？

这是一个例子： 这是第一个 JSON 对象

[
    {"text": " pen and ink and watercolour", "id": "x32505 ", "obj_count": 1855},
    {"text": " watercolour", "id": "x33202 ", "obj_count": 674},
    {"text": "pencil", "id": "AAT16013 ", "obj_count": 297}
]

这是第二个 json 对象

[
    {"text": " pen and ink and watercolour", "id": "x32505 ", "obj_count": 807},
    {"text": " watercolour", "id": "x33202 ", "obj_count": 97},
    {"text": " ink", "id": "AAT15012 ", "obj_count": 297}
]

我想要的是这样的：

[
   {"text":" pen and ink and watercolour","id":"x32505 ","obj_count": 2662 #summed},
   {"text":" watercolour","id":"x33202 ","obj_count": 771 #summed},
   {"text":" ink","id":"AAT15012 ","obj_count":297},
   {"text":"pencil","id":"AAT16013 ","obj_count":297}
]

Answer 1

使用dict来存储你是否看到了id

• 如果有，求和他们的obj_count
• 如果还没有，请保存该项目

values_a = [
    {"text": " pen and ink and watercolour", "id": "x32505 ", "obj_count": 1855},
    {"text": " watercolour", "id": "x33202 ", "obj_count": 674},
    {"text": "pencil", "id": "AAT16013 ", "obj_count": 297}
]

values_b = [
    {"text": " pen and ink and watercolour", "id": "x32505 ", "obj_count": 807},
    {"text": " watercolour", "id": "x33202 ", "obj_count": 97},
    {"text": " ink", "id": "AAT15012 ", "obj_count": 297}
]

result = {}
for item in [*values_a, *values_b]:
    if item['id'] in result:
        result[item['id']]['obj_count'] += item['obj_count']
    else:
        result[item['id']] = item

# back to list of items
result = list(result.values())

Answer 2

是的

任何加载/保存都可以使用 json 模块完成（虽然下面没有使用）

def sum_list_of_dict(source, add):
    for add_elem in add:
        found = False
        for source_elem in source:
            if add_elem["id"] == source_elem["id"]:
                source_elem["obj_count"] += add_elem["obj_count"]
                found = True
                break  # dupes should not be present
        if not found:
            source.append(add_elem)
    return source


data1 = [
    {"text": "pen and ink and watercolour", "id": "x32505", "obj_count": 1855},
    {"text": "watercolour", "id": "x33202", "obj_count": 674},
    {"text": "pencil", "id": "AAT16013", "obj_count": 297},
]

data2 = [
    {"text": "pen and ink and watercolour", "id": "x32505", "obj_count": 807},
    {"text": "watercolour", "id": "x33202", "obj_count": 97},
    {"text": "ink", "id": "AAT15012", "obj_count": 297},
]

data3 = sum_list_of_dict(data1, data2)

# just for pretty printing
from pprint import pprint
pprint(data3)

输出

[{'id': 'x32505', 'obj_count': 2662, 'text': 'pen and ink and watercolour'},
 {'id': 'x33202', 'obj_count': 771, 'text': 'watercolour'},
 {'id': 'AAT16013', 'obj_count': 297, 'text': 'pencil'},
 {'id': 'AAT15012', 'obj_count': 297, 'text': 'ink'}]