如何将一个 JSON 中的图像属性替换为另一个 JSON 中的图像属性？

Question

我正在尝试从一组 json 文件复制图像字段并替换另一组 JSON 文件中的图像字段。

我从中提取的 JSON 文件结构：

[
    {
        "\ufeffFile Name": "16.png",
        "image": "https://arweave.net/v8OOGgKmlAZF56bpGQRv1nM691gu2FMlrNK3KY-3HZk"
    }
]

我需要替换的 JSON 文件结构：

{
  "name": "name",
  "symbol": "KK",
  "description": "description",
  "seller_fee_basis_points": 1000,
  "image": "image.png",
  "external_url": "https://www.image.net",
  "edition": 16,
}

代码：

import json
import os



def getFileImage(fp):
    with open(fp, 'r') as ff:
        try:
            return json.load(ff)['image']
        except:
            return None



def ReadAndReplace(filename, image):
    with open(filename, 'r') as ff:
        try:
            data = json.load(ff)
            data['image'] = image
            return json.dumps(data, indent = 4)
        except:
            print(f'Could not process file {filename}')
            return None



def Save(filename, data):
    with open(filename, 'w') as ff:
        ff.write(data)



def EnsureOutput():
    if not os.path.exists('output'):
        os.mkdir('output')

    if not os.path.exists('input') or not os.path.exists('toReplace'):
        print('Please create "input" and "toReplace" folders')
        exit()


def main():
    EnsureOutput()

    for i in os.listdir('toReplace'):
        filepath1 = os.path.join('input', i)
        filepath2 = os.path.join('toReplace', i)
        outpath = os.path.join('output', i)

    if os.path.exists(filepath1):
        image = getFileImage(filepath1)
        data = ReadAndReplace(filepath2, image)
        Save(outpath, data)
    else:
        print(f'No input file for toReplace "{i}" was found')



main()

当我运行此代码时，图像字段更新为 NULL 而不是我需要的链接。

Answer 1

您正在加载的输入是一个 JSON 数组，因此被解析为一个 python 列表，您显然无法像您尝试那样通过键访问它。
您首先需要访问数组中的对象，然后可以使用键访问该对象。

请参阅以下内容：

input = """
[
    {
        "\ufeffFile Name": "16.png",
        "image": "https://arweave.net/v8OOGgKmlAZF56bpGQRv1nM691gu2FMlrNK3KY-3HZk"
    }
]
"""

input_parsed = json.loads(input)
print(type(input_parsed))
print(input_parsed[0]["image"])

预期输出：

<class 'list'>
https://arweave.net/v8OOGgKmlAZF56bpGQRv1nM691gu2FMlrNK3KY-3HZk

对于您的 ReadAndReplace() 函数，这将如下所示：

def read_and_replace(filename, image):
    with open(filename, 'r') as ff:
        try:
            # data is a list
            data = json.load(ff)
            # be sure the list has actually one value exactly
            if len(data) == 1:
                data[0]['image'] = image
            return json.dumps(data, indent=4)
        except (json.JSONDecodeError, KeyError):
            print(f'Could not process file {filename}')
            return None