BeautifulSoup 在网页上找不到表格

Question

我正在尝试从网站上的第一个表中获取数据。我在这里查看了类似的问题并尝试了许多给定的解决方案，但似乎无法找到表格并最终找到表格中的数据。

我试过了：

from bs4 import BeautifulSoup  
from selenium import webdriver  
driver = webdriver.Chrome('C:\\folder\\chromedriver.exe')  
url = 'https://docs.microsoft.com/en-us/windows/release-information/'  
driver.get(url)  

tbla = driver.find_element_by_name('table') #attempt using by element name  
tblb = driver.find_element_by_class_name('cells-centered') #attempt using by class name  
tblc = driver.find_element_by_xpath('//*[@id="winrelinfo_container"]/table[1]') #attempt by using xpath  

并尝试使用美丽的汤

html = driver.page_source
soup = BeautifulSoup(html,'html.parser')
table = soup.find("table", {"class": "cells-centered"})
print(len(table))

非常感谢任何帮助。

Answer 1

表存在于iframe 中，您需要先切换iframe 才能访问table。

诱导WebDriverWait() 并等待frame_to_be_available_and_switch_to_it() 并跟随定位器。

诱导WebDriverWait() 并等待visibility_of_element_located() 和跟随定位器。

driver.get("https://docs.microsoft.com/en-us/windows/release-information/")
WebDriverWait(driver,10).until(EC.frame_to_be_available_and_switch_to_it((By.ID,"winrelinfo_iframe")))
table=WebDriverWait(driver,10).until(EC.visibility_of_element_located((By.CSS_SELECTOR,"table.cells-centered")))

您需要导入以下库。

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

---

或者你使用下面的代码和xpath。

driver.get("https://docs.microsoft.com/en-us/windows/release-information/")
WebDriverWait(driver,10).until(EC.frame_to_be_available_and_switch_to_it((By.ID,"winrelinfo_iframe")))
table=WebDriverWait(driver,10).until(EC.presence_of_element_located((By.XPATH,'//*[@id="winrelinfo_container"]/table[1]')))

---

您可以进一步将表格数据导入 pandas 数据框，然后导出为 csv 文件。您需要导入 pandas。

driver.get("https://docs.microsoft.com/en-us/windows/release-information/")
WebDriverWait(driver,10).until(EC.frame_to_be_available_and_switch_to_it((By.ID,"winrelinfo_iframe")))
table=WebDriverWait(driver,10).until(EC.presence_of_element_located((By.XPATH,'//*[@id="winrelinfo_container"]/table[1]'))).get_attribute('outerHTML')
df=pd.read_html(str(table))[0]
print(df)
df.to_csv("path/to/csv")

导入熊猫：pip install pandas

然后添加下面的库

import pandas as pd

Answer 2

表格位于<iframe> 内部，因此BeautifulSoup 在原始页面中看不到它：

import requests 
from bs4 import BeautifulSoup


url = 'https://docs.microsoft.com/en-us/windows/release-information/'
soup = BeautifulSoup(requests.get(url).content, 'html.parser')
soup = BeautifulSoup(requests.get(soup.select_one('iframe')['src']).content, 'html.parser')

for row in soup.select('table tr'):
    print(row.get_text(strip=True, separator='\t'))

打印：

Version Servicing option    Availability date   OS build    Latest revision date    End of service: Home, Pro, Pro Education, Pro for Workstations and IoT Core End of service: Enterprise, Education and IoT Enterprise
2004    Semi-Annual Channel 2020-05-27  19041.546   2020-10-01  2021-12-14  2021-12-14  Microsoft recommends
1909    Semi-Annual Channel 2019-11-12  18363.1110  2020-09-16  2021-05-11  2022-05-10
1903    Semi-Annual Channel 2019-05-21  18362.1110  2020-09-16  2020-12-08  2020-12-08
1809    Semi-Annual Channel 2019-03-28  17763.1490  2020-09-16  2020-11-10  2021-05-11
1809    Semi-Annual Channel (Targeted)  2018-11-13  17763.1490  2020-09-16  2020-11-10  2021-05-11
1803    Semi-Annual Channel 2018-07-10  17134.1726  2020-09-08  End of service  2021-05-11

...and so on.