如何在xpath python中强制转换变量

Question

    from __future__ import unicode_literals

import requests
from scrapy.selector import Selector

def fetch_page(url):
    r = requests.get(url)
    return r.text

def upso_list_from_listpage(url):
    html = fetch_page(url)
    sel = Selector(text=html)
    upso_lists = []
    for i in range ( 1, 31 ):
        upso_list = sel.xpath ( '//*[@id="List_['"+i+"']"]/div[4]/span/a/text()').extract()
        upso_list.append ( upso_lists )
    #upso_list = sel.xpath('//*[@id="List_0"]/div[4]/span/a/text()').extract()
    #upso_list = sel.css('.nclicks(mai.text1)').extract()
    return upso_lists
from pprint import pprint
pprint(upso_list_from_listpage('http://mokorea.com/ajax/makeBusinessList.php?_method=get&grp=&major=4&cat=&keyword=&hchar=&recom=&page=1&dist=500&gLat=59.8767&gLong=30.4016'))

我想读多行。有人能帮我把xpath改成变量吗？我的xpath会增加（列表0、列表1、列表2、列表3…）

Answer 1

您的代码是：

for i in range ( 1, 31 ): 
    upso_list = sel.xpath ( '//*[@id="List_' + str(i) + '"]/div[4]/span/a/text()').extract()