Python3,Beautifulsoup4标签混乱

时间:2016-09-15 10:08:36

标签: beautifulsoup python-3.5

我正在尝试从亚马逊获取一些数据,我的代码是:

import requests, bs4

source_code = requests.get("https://www.amazon.com/s/ref=sr_nr_p_n_feature_keywords_0?fst=as%3Aoff&rh=n%3A2335752011%2Cn%3A%212335753011%2Cn%3A7072561011%2Cn%3A2407749011%2Cp_89%3AHuawei%2Cp_n_feature_keywords_four_browse-bin%3A6787346011&bbn=2407749011&ie=UTF8&qid=1473923594&rnid=6787345011", 
    headers={
    "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.110 Safari/537.36"
})
source_code.raise_for_status()

soup = bs4.BeautifulSoup(source_code.text, 'lxml')
mobile_div = soup.find_all("div", class_="a-row a-spacing-small")
for mobile_name in mobile_div:
    print(mobile_name.a.find_next("h2").string)

它输出正常,但当我使用

print(mobile_name.a.h2.string)

而不是它显示以下错误:

print(mobile_name.a.h2.string)
AttributeError: 'NoneType' object has no attribute 'string'

我的标记是: enter image description here

任何人都可以解释为什么我会收到此错误吗?

1 个答案:

答案 0 :(得分:0)

因为返回的第一个锚是:

<a class="a-button-text" href="/gp/help/contact-us/general-questions.html/ref=sr_hms_cs/155-8370713-5732665?browse_node_id=468556&amp;ie=UTF8&amp;qid=1473939395" role="button">contact us</a>

它没有 h2 子/后代,调用 find_next h2 的锚之后随处可见,所以即使它没有孩子会找到下一个。 a.h2查找锚点的子/后代,因此上面的第一个锚点返回None。

find_all_next() and find_next()

这些方法使用.next_elements迭代文档之后的任何标记和字符串。 find_all_next()方法返回所有匹配项,find_next()仅返回第一个匹配项:

这个简单的例子应该

In [34]: html = """<div>
          <a class="a-button-text" href="/fof.com">foobar</a> 
          <h2 class="sibling"> blah</h2> 
          <div ><h2 class="nexted"> blah</h2></div> 
          </div>"""

In [34]: soup = bs4.BeautifulSoup(html, 'lxml')

In [35]: a = soup.div.a
In [36]: print(a.h2) # a has no direct descendants so we get None
None
In [37]: a.find_next("h2") # finds the next h2 anywhere after the anchor 
Out[37]: <h2 class="sibling"> blah</h2>


In [38]: a.find_next_siblings("h2") # finds any h2's in the tree that are siblings
Out[38]: [<h2 class="sibling"> blah</h2>]

In [39]: a.find_all_next("h2") # finds all h2s anywhere after 
Out[39]: [<h2 class="sibling"> blah</h2>, <h2 class="nexted"> blah</h2>]