抓取：无法从 Web 访问信息

Question

我正在从这个 url 中抓取一些信息：https://www.rockethub.com/projects/34210-lunar-lion-the-first-ever-university-led-mission-to-the-moon#description-tab

在我抓取描述之前一切都很好。我试了又试，但到目前为止都失败了。似乎我无法获得该信息。这是我的代码：

html = urllib.urlopen("https://www.rockethub.com/projects/34210-lunar-lion-the-first-ever-university-led-mission-to-the-moon")
tree=BeautifulSoup(html, "lxml")
description=tree.find('div',{'id':'description_section','class':'description-section'})

大家有什么建议吗？

Answer 1

我使用 XML 包进行网页抓取，但我无法获得您在 BeautifulSoup 中描述的描述部分。

但是，如果您只想废弃此页面，则可以下载该页面。那么：

页面 = htmlTreeParse("Lunar Lion - the first ever university-led mission to the Moon _ RocketHub.html", useInternal = TRUE,编码="utf8")

unlist(xpathApply(page, '//div[@id="description_section"]', xmlValue))

我试过R码下载，也没找到description_section

url="https://www.rockethub.com/projects/34210-lunar-lion-the-first-ever-university-led-mission-to-the-moon"

download.file(url,"page.html",模式="w")

也许我们必须在函数中添加一些选项download.file。希望html高手能帮忙

Answer 2

您需要提出额外请求才能获得描述。这是一个完整的工作示例，使用 requests + BeautifulSoup:

import requests
from bs4 import BeautifulSoup

url = "https://www.rockethub.com/projects/34210-lunar-lion-the-first-ever-university-led-mission-to-the-moon/"
with requests.Session() as session:
    session.headers = {
        "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36"
    }

    # get the token
    response = session.get(url)
    soup = BeautifulSoup(response.content, "html.parser")
    token = soup.find("meta", {"name": "csrf-token"})["content"]

    # get the description
    description_url = url + "description"
    response = session.get(description_url, headers={"X-CSRF-Token": token, "X-Requested-With": "XMLHttpRequest"})

    soup = BeautifulSoup(response.content, "html.parser")
    description = soup.find('div', {'id':'description_section', 'class': 'description-section'})
    print(description.get_text(strip=True))

Answer 3

我发现了如何使用 R 进行报废：

library("rvest")

url="https://www.rockethub.com/projects/34210-lunar-lion-the-first-ever-university-led-mission-to-the-moon/description"

url %>% 
  html() %>% 
  html_nodes(xpath='//div[@id="description_section"]', xmlValue) %>%
  html_text()

抓取：无法从 Web 访问信息

Scraping: cannot access information from web

python

beautifulsoup

html-parsing

web-scraping