python - 循环浏览页面以进行网页抓取

Question

我正在尝试访问此站点上的数据:http://surge.srcc.lsu.edu/s1.html 。到目前为止，我的代码循环遍历下拉菜单，并且我想循环表格顶部的页面 [1] [2] .. 等。我尝试使用 Select，但收到错误，Select 无法与 span 一起使用:“UnexpectedTagNameException:Select 仅适用于元素，不适用于 ”。

# importing libraries
from selenium import webdriver
import time
from selenium.webdriver.support.ui import Select
from bs4 import BeautifulSoup
import re

driver = webdriver.Firefox()
driver.get("http://surge.srcc.lsu.edu/s1.html")

# definition for switching frames
def frame_switch(css_selector):
  driver.switch_to.frame(driver.find_element_by_css_selector(css_selector))  

# data is in an iframe
frame_switch("iframe")

html_source = driver.page_source
nameSelect = Select(driver.find_element_by_xpath('//select[@id="storm_name"]'))
stormCount = len(nameSelect.options)
data=[]
for i in range(1, stormCount):
    print("starting loop on option storm " + nameSelect.options[i].text)
    nameSelect.select_by_index(i)
    time.sleep(3)


    yearSelect = Select(driver.find_element_by_xpath('//select[@id="year"]'))
    yearCount = len(yearSelect.options)
    for j in range(1, yearCount):
        print("starting loop on option year " + yearSelect.options[j].text)
        yearSelect.select_by_index(j)


        time.sleep(2)

这是我在选择页面时遇到问题的地方:

        change_page=Select(driver.find_element_by_class_name("yui-pg-pages"))
        page_count = len(change_page.options)
        for k in range(1, page_count):
            change_page.select_by_index(k)



        # Select Page & run following code
            soup = BeautifulSoup(driver.page_source, 'html.parser')
            print(soup.find_all("tbody", {"class" : re.compile(".*")})[1])
            # get the needed table body
            table=soup.find_all("tbody", {"class" : re.compile(".*")})[1] 
            rows = table.find_all('tr')
            for row in rows:
                cols = row.find_all('td')
                cols = [ele.text.strip() for ele in cols]
                data.append(cols)

Answer 1

改用 xpath 选择器。

driver.find_element_by_xpath('//a[@class="yui-pg-next"]')  

然后在可以与下一个按钮交互的同时循环即可。如果在循环浏览页面时页面数量可以改变，我更喜欢这种方法。您不需要使用Select。事实上，我认为 Select 除了下拉菜单之外没有其他用途。

或者，如果您需要使用页面链接来执行此操作，因为页面不会经常更改，您可以尝试以下操作:

# Use find_elements_by_xpath to select multiple elements.
pages = driver.find_elements_by_xpath('//a[@class="yui-pg-page"]')

# loop through results
for page_link in pages:
    page_link.click()
    # do stuff.