Python对列表中的每个条目都做了什么？

Question

所以我一直在通过python与trelloapi交互。 当我得到我的卡片时，它会返回（除其他外）这个列表（将它转换成JSON表示漂亮）

{
  "cards": [
    {
      "id": "censored",
      "checkItemStates": null,
      "closed": false,
      "dateLastActivity": "2017-03-13T20:31:15.161Z",
      "desc": "",
      "descData": null,
      "idBoard": "censored",
      "idList": "censored",
      "idMembersVoted": [

  ],
  "idShort": 1,
  "idAttachmentCover": null,
  "manualCoverAttachment": false,
  "idLabels": [

  ],
  "name": "testcard1",
  "pos": 65535,
  "shortLink": "censored",
  "badges": {
    "votes": 0,
    "viewingMemberVoted": false,
    "subscribed": false,
    "fogbugz": "",
    "checkItems": 0,
    "checkItemsChecked": 0,
    "comments": 0,
    "attachments": 0,
    "description": false,
    "due": null,
    "dueComplete": false
  },
  "dueComplete": false,
  "due": null,
  "email": "censored",
  "idChecklists": [

  ],
  "idMembers": [

  ],
  "labels": [

  ],
  "shortUrl": "censored",
  "subscribed": false,
  "url": "censored",
  "attachments": [

  ],
  "pluginData": [

  ]
}
  ]
}

我试过了

for card in x.cards:
print "hi"

但它给了我这个错误

AttributeError: 'list' object has no attribute 'cards'

我的最终目标是获得每个“name”属性并将其打印到txt文件中（我知道如何将内容写入.txt文件）

在最后的结果，会有更多的thn 1卡ofc。你知道吗

Answer 1

看起来Java开发人员同意您的意见，即generate应该接受Supplier<? extends T>，因为它在Java 9中被更改了。见JDK-8132097 (Stream.generate should use a covariant Supplier as parameter)：

Description

The signature of Stream.generate doesn't to use a wildcard (? extends) hence some programs are rejected even if they are valid. The signature should be public static Stream generate(Supplier<? extends T> s).

这种改变是有意义的，因为做了这样的事情：

Stream<CharSequence> stream = Stream.generate(new Supplier<String>() {
    @Override public String get() {
      // implementation...
    }
});

应该完全有效。诚然，这是一个非常做作的例子，但重点是：Supplier应该允许用T的任何子类型进行参数化。与PEC相关的是Supplier是T的产生者