从 python/selenium 与 javascript 可滚动容器交互

Question

我正在尝试使用 Selenium/Python 自动从 http://factfinder.census.gov 下载数据集。我是 Javascript 新手，如果这是一个容易解决的问题，我深表歉意。我现在正在处理代码的开头部分，它应该：

1. 去here
2. 点击“主题”按钮
3. 点击“主题”并加载新页面后，点击“数据集”
4. 选择我需要的数据集，最好通过索引（子）表。

我卡在第 3 步。这是截图；似乎我想访问带有“scrollable_container_topics”的div，然后遍历或索引以获取其子节点（在这种情况下，我想要最后一个子节点）。我曾尝试使用 script_execute，然后通过 id 和类名定位元素，但到目前为止没有任何效果。如有任何指示，我将不胜感激。

这是我的代码：

import os
import re
import time
from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions
from selenium.webdriver.support.wait import WebDriverWait
from selenium.webdriver.support.select import Select


# A list of all the variables we want to extract; corresponds to "Topics" field on site
topics = ["B03003", "B05001"]

# A list of all the states we want to extract data for (currently, strings; is there a numeric code?)
states = ["New Jersey", "Georgia"]

# A vector of all the years we want to extract data for [lower, upper) *Note* this != range of years covered by data
years = range(2009, 2010)

# Define the class
class CensusSearch:

    # Initialize and set attributes of the query
    def __init__(self, topic, state, year):

        """
        :type topic: str
        :type state: str
        :type year: int
        """
        self.topic = topic
        self.state = state
        self.year = year


    def setUp(self):

       # self.driver = webdriver.Chrome("C:/Python34/Scripts/chromedriver.exe")
        self.driver = webdriver.Firefox()

    def extractData(self):
        driver = self.driver
        driver.set_page_load_timeout(1000000000000)
        driver.implicitly_wait(100)

        # Navigate to site; this url = after you have already chosen "Advanced Search"
        driver.get("http://factfinder.census.gov/faces/nav/jsf/pages/searchresults.xhtml?refresh=t")
        driver.implicitly_wait(10)

        # FIlter by dataset (want the ACS 1, 3, and 5-year estimates)

        driver.execute_script("document.getElementsByClassName('leftnav_btn')[0].click()") # click the "Topics" button
        driver.implicitly_wait(20) 

        # This is where I am stuck; I've tried the following: 
        getData = driver.find_element_by_id("ygtvlabelel172")
        getData.click()
        driver.implicitly_wait(10)


        # Filter geographically: select all counties in the United States and Puerto Rico
        # Click "Geographies" button
        driver.execute_script("document.getElementsByClassName('leftnav_btn')[1].click()")
        driver.implicitly_wait(10)

        drop_down = driver.find_element_by_class_name("popular_summarylevel")
        select_box = Select(drop_down)
        select_box.select_by_value("050")

    # Once "Geography" is clicked, select "County - 050" from the drop-down menu; then select "All US + Puerto Rico"
    drop_down_counties = driver.find_element_by_id("geoAssistList")
    select_box_counties = Select(drop_down_counties)
    select_box_counties.select_by_index(1)

    # Click the "ADD TO YOUR SELECTIONS" button
    driver.execute_script("document.getElementsByClassName('button-g')[0].click()")
    driver.implicitly_wait(10)

    def tearDown(self):
        self.driver.quit()

    def main(self):
        #print(getattr(self))
        print(self.state)
        print(self.topic)
        print(self.year)
        self.setUp()
        self.extractData()
        self.tearDown()


for a in topics:
    for b in states:
        for c in years:
            query = CensusSearch(a, b, c)
            query.main()

print("done")

Answer 1

需要解决的几个问题：

• 您不必使用 document.getElement.. 方法 - selenium 有自己的方法来定位页面上的元素
• 无需处理隐式等待（另外，请确保您了解调用 implicitly_wait() 不会像 time.sleep() 一样 - 您不会立即获得时间延迟）或在这种情况下页面加载超时 - 只是在页面上执行操作之前使用Explicit Waits

这是一个点击“主题”然后点击“数据集”的工作代码：

from selenium import webdriver
from selenium.webdriver import ActionChains
from selenium.webdriver.common.by import By
from selenium.webdriver.support.wait import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC


driver = webdriver.Firefox()
driver.get("http://factfinder.census.gov/faces/nav/jsf/pages/searchresults.xhtml?refresh=t")

wait = WebDriverWait(driver, 10)
actions = ActionChains(driver)

# click "Topics"
topics = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, "a#topic-overlay-btn")))
driver.execute_script("arguments[0].click();", topics)

# click "Dataset"
dataset = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, "span[title=Dataset]")))
dataset.click()