python - 使用 Python 从 API 更改 Json

Question

我有一个来自 API 的 json 代码，我想用下面的代码获得新的聊天成员，但我只得到前两个结果而不是最后一个(测试人员)。为什么？它应该遍历整个 json 文件，不是吗？

r = requests.get("https://api.../getUpdates").json()

chat_members = []

a = 0
for i in r:
    chat_members.append(r['result'][a]['message']['new_chat_members'][0]['last_name'])
a = a + 1

此处为 Json:

{"ok":true,"result":[{"update_id":213849278,
"message":{"message_id":37731,"from":{"id":593029363,"is_bot":false,"first_name": "@tutu"},"chat":{"id":-1001272017174,"title":"tester account","username":"v_glob","type":"supergroup"},"date":1537470595,"new_chat_participant":{"id":593029363,"is_bot":false,"first_name":"tutu "},"new_chat_member":{"id":593029363,"is_bot":false,"first_name":"\u7535\u62a5\u589e\u7c89\uff0c\u4e2d\u82f1\u6587\u5ba2\u670d\uff0c\u62c9\u4eba\u6e05\u5783\u573e\u8f6f\u4ef6\uff0c\u5e7f\u544a\u63a8\u5e7f\uff0cKYC\u6750\u6599\u8ba4\u8bc1\uff0c","last_name":"@tutupeng"},"new_chat_members":[{"id":593029363,"is_bot":false,"first_name":"\u7535\u62a5\u589e\u7c89\uff0c\u4e2d\u82f1\u6587\u5ba2\u670d\uff0c\u62c9\u4eba\u6e05\u5783\u573e\u8f6f\u4ef6\uff0c\u5e7f\u544a\u63a8\u5e7f\uff0cKYC\u6750\u6599\u8ba4\u8bc1\uff0c","last_name":"@tutu"}]}},{"update_id":213849279,
"message":{"message_id":37732,"from":{"id":658150956,"is_bot":false,"first_name":"Rebecca","last_name":"Lawson"},"chat":{"id":-10012720,"title":"v glob OFFICIAL","username":"v_glob","type":"supergroup"},"date":1537484441,"new_chat_participant":{"id":65815,"is_bot":false,"first_name":"Rebecca","last_name":"Lawson"},"new_chat_member":{"id":65815,"is_bot":false,"first_name":"Rebecca","last_name":"Lawson"},"new_chat_members":[{"id":65815,"is_bot":false,"first_name":"Rebecca","last_name":"Lawson"}]}},{"update_id":213849280,
"message":{"message_id":12,"from":{"id":696749142,"is_bot":false,"first_name":"daniel","language_code":"cs-cz"},"chat":{"id":696749142,"first_name":"daniel","type":"private"},"date":1537537013,"text":"/stat","entities":[{"offset":0,"length":5,"type":"bot_command"}]}},{"update_id":213849281,
"message":{"message_id":37740,"from":{"id":669620,"is_bot":false,"first_name":"Ivan","last_name":"Tester"},"chat":{"id":-100127201,"title":"test account","username":"v_glob","type":"supergroup"},"date":1537537597,"new_chat_participant":{"id":669620191,"is_bot":false,"first_name":"Ivan","last_name":"Tester"},"new_chat_member":{"id":669620191,"is_bot":false,"first_name":"Ivan","last_name":"Tester"},"new_chat_members":[{"id":669620191,"is_bot":false,"first_name":"Ivan","last_name":"Tester"}]}}]}

Answer 1

因为您遍历了整个响应指令。顶层只有两个项目，因此这就是您要迭代的项目。请注意，您实际上并没有使用迭代器变量，并且您有一个完全不必要的单独计数器。

相反，您应该迭代结果字典:

for result in r['result']:
    if "new_chat_members" in result['message']:
        chat_members.append(result['message']['new_chat_members'][0]['last_name'])