July 2017
Intermediate to advanced
398 pages
11h 54m
Chinese
Content preview from Python数据处理
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230
｜
第
11
章
图 11-5：元素选项
对于不同的浏览器，工具的语言和交互可能差别很大，但是菜单选项应该同
在这里描述的类似，这应该让你对如何访问数据和这些交互操作有了一些了
解。
除了找到元素和内容之外，开发者工具展示了大量有关页面上节点结构和家族关系的信
息。在开发者工具中，通常会有一个检视标签，展示当前元素的父元素列表。该列表中的
元素通常可以被点击或者选择，所以你可以通过一个简单的点击遍历
DOM
。在
Chrome
中，这个列表在开发者工具和上方页面之间的灰色部分。
我们已经查看了
Web
页面的组织结构，以及如何同它们交互来更好地理解内容的位置。现
在来研究浏览器中让网页抓取更加简单的其他强大工具。
11.2.2
网络
/
时间线
：
页面是如何加载的
分析开发者工具中的时间线（
Timeline
）
/
网络（
Network
）标签将让你深刻理解页面内容
是如何加载的以及加载的顺序。页面加载的时间和方式可以极大地影响你决定抓取页面的
网页抓取：获取并存储网络数据
｜
231
方式。有时，理解内容来源是抓取所需内容的“快捷方式”。
网络或时间线标签展示了已加载的
URL
、加载顺序和加载所需时间。图
11-6
展示了
Enough
项目页面在
Chrome
中网络标签的样子。对于不同的浏览器，你可能需要重新加载
页面，来查看网络标签页面的内容。 ...
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.