使用BeautifulSoup库的Python代码从td标记中获取href属性链接

Question

我是Python的新手，有人建议我使用Beautiful Soup进行网络爬虫，但我在获取第4列年份基础上第2列td标签的href属性时遇到了问题。

<table class="tableFile2" summary="Results">
         <tr>
            <th width="7%" scope="col">Filings</th>
            <th width="10%" scope="col">Format</th>
            <th scope="col">Description</th>
            <th width="10%" scope="col">Filing Date</th>
            <th width="15%" scope="col">File/Film Number</th>
         </tr>
<tr>
<td nowrap="nowrap">8-K</td>
<td nowrap="nowrap"><a href="/Archives/edgar/data/320193/000119312513199324/0001193125-13-199324-index.htm" id="documentsbutton">&nbsp;Documents</a></td>
<td class="small" >Current report, items 8.01 and 9.01
<br />Acc-no: 0001193125</td>
            <td>2013-05-03</td>
            <td nowrap="nowrap"><a href="/cgi-bin/browse-edgar?action=getcompany&amp;filenum=000-10030&amp;owner=include&amp;count=40">000-10030</a><br>13813281         </td>
         </tr>
<tr class="blueRow">
<td nowrap="nowrap">424B2</td>
<td nowrap="nowrap"><a href="/Archives/edgar/data/320193/000119312513191849/0001193125-13-191849-index.htm" id="documentsbutton">&nbsp;Documents</a></td>
<td class="small" >Prospectus [Rule 424(b)(2)]<br />Acc-no: 0001193125</td>
            <td>2013-05-01</td>
            <td nowrap="nowrap"><a href="/cgi-bin/browse-edgar?action=getcompany&amp;filenum=333-188191&amp;owner=include&amp;count=40">333-188191</a><br>13802405         </td>
         </tr>
<tr>
<td nowrap="nowrap">FWP</td>
<td nowrap="nowrap"><a href="/Archives/edgar/data/320193/000119312513189053/0001193125-13-189053-index.htm" id="documentsbutton">&nbsp;Documents</a></td>
<td class="small" >Filing under Securities Act Rules 163/433 of free writing prospectuses<br />Acc-no: 0001193125-13-189053&nbsp;(34 Act)&nbsp; Size: 52 KB            </td>
            <td>2013-05-01</td>
            <td nowrap="nowrap"><a href="/cgi-bin/browse-edgar?action=getcompany&amp;filenum=333-188191&amp;owner=include&amp;count=40">333-188191</a><br>13800170         </td>
         </tr>
</table>



table = soup.find('table', class="tableFile2")

rows = table.findAll('tr')
for tr in rows:
  cols = tr.findAll('td')
  if "2013" in cols[3]
    link = cols[1].find('a').get('href')
  print

- Zaid Iqbal

---

所以你想要从“格式”和“申报日期”这两列获取数据？ - That1Guy

Answer 1

这个方法适用于我使用的Python 2.7:

table = soup.find('table', {'class': 'tableFile2'})
rows = table.findAll('tr')
for tr in rows:
    cols = tr.findAll('td')
    if len(cols) >= 4 and "2013" in cols[3].text:
        link = cols[1].find('a').get('href')
        print link

你之前的代码存在以下几个问题：

1. soup.find() 需要一个属性字典（例如 {'class' : 'tableFile2'}）
2. 并非每个 cols 实例都至少有3列，因此您需要先检查其长度。

- Charles Marsh