python之在 Django 中使用请求解析 JSON

我正在使用 Django 应用程序中的请求进行 API 调用。我不断收到关于名称的关键错误。 json 响应非常大，所以我只选择某些字段来使用。但错误出现在 json 列表中的第一项上。

json 的前几行看起来像这样，

"cards": [ 
    { 
      "name": "Air Elemental", 
      "manaCost": "{3}{U}{U}", 
      "cmc": 5, 
      "colors": [ 
        "Blue" 
      ], 
      "type": "Creature — Elemental", 
      "types": [ 
        "Creature" 
      ], 
      "subtypes": [ 
        "Elemental" 
      ], 

在我看来，我正在像这样解析 json，

def graphs(request): 
    if request.user.is_authenticated(): 
        parsedData = [] 
        req = requests.get('https://api.magicthegathering.io/v1/cards') 
        jsonList = [] 
        jsonList.append(json.loads(req.content.decode())) 
        cardData = {} 
        for cards in jsonList: 
            cardData['name'] = cards['name'] 
            cardData['manaCost'] = cards['manaCost'] 
            cardData['colors'] = cards['colors'] 
            cardData['type'] = cards['type'] 
            cardData['rarity'] = cards['rarity'] 
            cardData['set'] = cards['set'] 
            cardData['text'] = cards['text'] 
            cardData['flavor'] = cards['flavor'] 
            cardData['artist'] = cards['artist'] 
            cardData['power'] = cards['power'] 
            cardData['toughness'] = cards['toughness'] 
            cardData['layout'] = cards['layout'] 
            cardData['multiverseid'] = cards['multiverseid'] 
            cardData['id'] = cards['id'] 
        parsedData.append(cardData) 
        return render(request, 'graphs/graphs.html', {'data': parsedData}) 
    else: 
        return redirect('index') 

错误

KeyError at /graphs/graphs/ 
'name' 

在我看来，我正在像这样访问数据，

 {% for key in cards %} 
                      <tr> 
                          <td>{{ key.name }}</td> 
                          <td>{{ key.manaCost }}</td> 
                          <td>{{ key.colors }}</td> 
                          <td>{{ key.type }}</td> 
                          <td>{{ key.rarity }}</td> 
                          <td>{{ key.set }}</td> 
                          <td>{{ key.text }}</td> 
                          <td>{{ key.flavor }}</td> 
                          <td>{{ key.artist }}</td> 
                          <td>{{ key.power }}</td> 
                          <td>{{ key.toughness }}</td> 
                          <td>{{ key.layout }}</td> 
                          <td>{{ key.multiverseid }}</td> 
                          <td>{{ key.id }}</td> 
                      </tr> 
                  {% endfor %} 

为什么我会收到 key 错误？

请您参考如下方法:

当你这样做的时候

json.loads(req.content.decode()) 

你得到一个字典，一个键，cards .

{'cards': [<list of cards>]} 

将其附加到 jsonList 没有意义，因为那时你有，

[{'cards': [<list of cards>]} 

当您遍历该列表时，您将获得开始时使用的单个字典。正如我们之前所说，该字典只有一个键，cards。 ，因此当您尝试访问 name 时会出现 key 错误不存在的 key 。

你真的想遍历 [<list of cards>] , 所以设置 jsonList改为该列表。

    req = requests.get('https://api.magicthegathering.io/v1/cards') 
    jsonData = json.loads(req.content.decode()) 
    jsonList = jsonData['cards'] 
    for cards in jsonList: 
        cardData = {}  # move this line inside the loop 
        cardData['name'] = cards['name'] 
        ... 
        # make sure this line is inside the loop so that you append 
        # every card to parsedData 
        parsedData.append(cardData)  

如评论和其他答案中所述，您可以使用请求的 json()简化代码的方法:

    req = requests.get('https://api.magicthegathering.io/v1/cards') 
    jsonList = req.json()['cards'] 
    for cards in jsonList: 
        ...