Iterate through all the rows in a table using python lxml xpath

问题

This is the source code of the html page I want to extract data from.

Webpage: http://gbgfotboll.se/information/?scr=table&ftid=51168 The table is at the bottom of the page

     <html>
               <table class="clCommonGrid" cellspacing="0">
                        <thead>
                            <tr>
                                <td colspan="3">Kommande matcher</td>
                            </tr>
                            <tr>
                                <th style="width:1%;">Tid</th>
                                <th style="width:69%;">Match</th>
                                <th style="width:30%;">Arena</th>
                            </tr>
                        </thead>

                        <tbody class="clGrid">

                    <tr class="clTrOdd">
                        <td nowrap="nowrap" class="no-line-through">
                            <span class="matchTid"><span>2014-09-26<!-- br ok --> 19:30</span></span>



                        </td>
                        <td><a href="?scr=result&amp;fmid=2669197">Guldhedens IK - IF Warta</a></td>
                        <td><a href="?scr=venue&amp;faid=847">Guldheden Södra 1 Konstgräs</a> </td>
                    </tr>

                    <tr class="clTrEven">
                        <td nowrap="nowrap" class="no-line-through">
                            <span class="matchTid"><span>2014-09-26<!-- br ok --> 13:00</span></span>



                        </td>
                        <td><a href="?scr=result&amp;fmid=2669176">Romelanda UF - IK Virgo</a></td>
                        <td><a href="?scr=venue&amp;faid=941">Romevi 1 Gräs</a> </td>
                    </tr>

                    <tr class="clTrOdd">
                    <td nowrap="nowrap" class="no-line-through">
                        <span class="matchTid"><span>2014-09-27<!-- br ok --> 13:00</span></span>



                    </td>
                    <td><a href="?scr=result&amp;fmid=2669167">Kode IF - IK Kongahälla</a></td>
                    <td><a href="?scr=venue&amp;faid=912">Kode IP 1 Gräs</a> </td>
                </tr>

                <tr class="clTrEven">
                    <td nowrap="nowrap" class="no-line-through">
                        <span class="matchTid"><span>2014-09-27<!-- br ok --> 14:00</span></span>



                    </td>
                    <td><a href="?scr=result&amp;fmid=2669147">Floda BoIF - Partille IF FK </a></td>
                    <td><a href="?scr=venue&amp;faid=218">Flodala IP 1</a> </td>
                </tr>


                        </tbody>
                </table>
        </html>

Right now i have this code that actually produces the result that i want..

import lxml.html
url = "http://gbgfotboll.se/information/?scr=table&ftid=51168"
html = lxml.html.parse(url)
for i in range(12):
    xpath1 = ".//*[@id='content-primary']/table[3]/tbody/tr[%d]/td[1]/span/span//text()" %(i+1)
    xpath2 = ".//*[@id='content-primary']/table[3]/tbody/tr[%d]/td[2]/a/text()" %(i+1)
    time = html.xpath(xpath1)[1]
    date = html.xpath(xpath1)[0]
    teamName = html.xpath(xpath2)[0]
    if date == '2014-09-27':
        print time, teamName

Gives the result:

13:00 Romelanda UF - IK Virgo

13:00 Kode IF - IK Kongahälla

14:00 Floda BoIF - Partille IF FK

Now to the question. I don't want to use for loop with range because its not stable, the rows can change in that table and if it goes out of bounds it will crash. So my question is how can I iterate as I do here in a safe way. Meaning it will iterate through all the rows that are available in the table. No more no less. Also if you have any other suggestion making the code better/faster please go ahead.

回答1:

The following code will iterate whatever the number of rows. The rows_xpath will directly filter on the target date. The xpaths are also created once, outside the for loop, so it should be faster.

import lxml.html
from lxml.etree import XPath
url = "http://gbgfotboll.se/information/?scr=table&ftid=51168"
date = '2014-09-27'

rows_xpath = XPath("//*[@id='content-primary']/table[3]/tbody/tr[td[1]/span/span//text()='%s']" % (date))
time_xpath = XPath("td[1]/span/span//text()[2]")
team_xpath = XPath("td[2]/a/text()")

html = lxml.html.parse(url)

for row in rows_xpath(html):
    time = time_xpath(row)[0].strip()
    team = team_xpath(row)[0]
    print time, team

来源：https://stackoverflow.com/questions/25964194/iterate-through-all-the-rows-in-a-table-using-python-lxml-xpath

标签

python

xpath

web-scraping

html-table

lxml