Python 使用 BeautifulSoup 解析表

Question

HTML 页面结构:

<table>
    <tbody>
        <tr>
           <th>Timestamp</th>
           <th>Call</th>
           <th>MHz</th>
           <th>SNR</th>
           <th>Drift</th>
           <th>Grid</th>
           <th>Pwr</th>
           <th>Reporter</th>
           <th>RGrid</th>
           <th>km</th> 
           <th>az</th>
        </tr>
        <tr>
           <td align="right">&nbsp;2019-12-10 14:02&nbsp;</td>
           <td align="left">&nbsp;DL1DUZ&nbsp;</td>
           <td align="right">&nbsp;10.140271&nbsp;</td>
           <td align="right">&nbsp;-26&nbsp;</td>
           <td align="right">&nbsp;0&nbsp;</td>
           <td align="left">&nbsp;JO61tb&nbsp;</td>
           <td align="right">&nbsp;0.2&nbsp;</td>
           <td align="left">&nbsp;F4DWV&nbsp;</td>
           <td align="left">&nbsp;IN98bc&nbsp;</td>
           <td align="right">&nbsp;1162&nbsp;</td>
           <td align="right">&nbsp;260&nbsp;</td>
        </tr>
        <tr>
           <td align="right">&nbsp;2019-10-10 14:02&nbsp;</td>
           <td align="left">&nbsp;DL23UH&nbsp;</td>
           <td align="right">&nbsp;11.0021&nbsp;</td>
           <td align="right">&nbsp;-20&nbsp;</td>
           <td align="right">&nbsp;0&nbsp;</td>
           <td align="left">&nbsp;JO61tb&nbsp;</td>
           <td align="right">&nbsp;0.2&nbsp;</td>
           <td align="left">&nbsp;F4DWV&nbsp;</td>
           <td align="left">&nbsp;IN98bc&nbsp;</td>
           <td align="right">&nbsp;1162&nbsp;</td>
           <td align="right">&nbsp;260&nbsp;</td>
        </tr>
    </tbody>
</table>

等等 tr-td... 我的代码:

from bs4 import BeautifulSoup as bs
import requests
import csv

base_url = 'some_url'
session = requests.Session()
request = session.get(base_url)
val_th = []
val_td = []

if request.status_code == 200:
    soup = bs(request.content, 'html.parser')
    table = soup.findChildren('table')
    tr = soup.findChildren('tr')
    my_table = table[0]
    my_tr_th = tr[0]
    my_tr_td = tr[1]
    rows = my_table.findChildren('tr')
    row_th = my_tr_th.findChildren('th')
    row_td = my_tr_td.findChildren('td')
    for r_th in row_th:
       heading = r_th.text
       val_th.append(heading)
    for r_td in row_td:
        data = r_td.text
        val_td.append(data)
    with open('output.csv', 'w') as f:
        a_pen = csv.writer(f)
        a_pen.writerow(val_th)
        a_pen.writerow(val_td)

1) 我打印了 1 行 td。如何确保页面上td的所有行都以csv形式显示？ 2) td 标签 - 页面上有很多。 3) 如果 my_tr_td = tr[1] 写为 my_tr_td = tr[1:50] - 这是错误的。 如何将 tr-td 行中的所有数据写入 csv 文件？

提前致谢。

Answer 1

让我们尝试一下:

import lxml.html
import csv
import requests

url = "http://wsprnet.org/drupal/wsprnet/spots"
res = requests.get(url)

doc = lxml.html.fromstring(res.text)

cols = []
#first, we need to extract the column headers, stuck all the way at the top, with the first one in a particular location and format

cols.append(doc.xpath('//table/tr/node()/text()')[0])
for item in doc.xpath('//table/tr/th'):
    typ = str(type(item.getnext()))
    if not 'NoneType' in typ:        
        cols.append(item.getnext().text)
#now for the actual data
inf = []
for item in doc.xpath('//table//tr//td'):
    inf.append(item.text.replace('\\xa02', '').strip()) #text info needs to be cleaned

#this will take all the data and split it into rows for each column
rows = [inf[x:x+len(cols)] for x in range(0, len(inf), len(cols))]

#finally, write to file:
with open("output.csv", "w", newline='') as f:
    writer = csv.writer(f)
    writer.writerow(cols) 
    for l in rows:
        writer.writerow(l)