从网页中提取URL并保存到磁盘

时间:2017-09-17 15:30:59

标签: python web-scraping python-requests

我正在尝试编写一个脚本,用文章的标题自动查询sci-hub.io,并将文章全文的PDF副本保存到我的计算机上,并附带特定的文件名。

为此,我编写了以下代码:

url = "http://sci-hub.io/"
data = read_csv("C:\\Users\\Sangeeta's\\Downloads\\distillersr_export (1).csv")
for index, row in data.iterrows():
    try:
        print('http://sci-hub.io/' + str(row['DOI']))
        res = requests.get('http://sci-hub.io/' + str(row['DOI']))
        print(res.content)
    except:
        print('NO DOI: ' + str(row['ref']))

这将打开一个CSV文件,其中包含DOI列表和要保存的文件名。对于每个DOI,它然后查询sci-hub.io以获取全文。显示的页面嵌入了PDF,但我现在不确定如何提取PDF的URL并将其保存到磁盘。

可以在下图中看到该页面的示例:

enter image description here

在此图片中,所需的网址为http://dacemirror.sci-hub.io/journal-article/3a257a9ec768d1c3d80c066186aba421/pajno2010.pdf

如何自动提取此URL,然后将PDF文件保存到磁盘?

当我打印res.content时,我明白了:

b'<!DOCTYPE html>\n<html>\n    <head>\n        <title></title>\n        <meta charset="UTF-8">\n        <meta name="viewport" content="width=device-width">\n    </head>\n    <body>\n    <style type = "text/css">\n        body {background-color:#F0F0F0}\n        div {overflow: hidden; position: absolute;}\n        #top {top:0;left:0;width:100%;height:50px;font-size:14px} /* 40px */\n        #content {top:50px;left:0;bottom:0;width:100%}\n        p {margin:0;padding:10px}\n        a {font-size:12px;font-family:sans-serif}\n        a.target {font-weight:normal;color:green;margin-left:10px}\n        a.reopen {font-weight:normal;color:blue;text-decoration:none;margin-left:10px}\n        iframe {width:100%;height:100%}\n        \n        p.agitation {padding-top:5px;font-size:20px;text-align:center}\n        p.agitation a {font-size:20px;text-decoration:none;color:green}\n\n        .banner {position:absolute;z-index:9999;top:400px;left:0px;width:300px;height:225px;\n                 border: solid 1px #ccc; padding: 5px;\n                 text-align:center;font-size:18px}\n        .banner img {border:0}\n        \n        p.donate {padding:0;margin:0;padding-top:5px;text-align:center;background:green;height:40px}\n        p.donate a {color:white;font-weight:bold;text-decoration:none;font-size:20px}\n\n        #save {position:absolute;z-index:9999;top:180px;left:8px;width:210px;height:36px;\n                 border-radius: 4px; border: solid 1px #ccc; padding: 5px;\n                 text-align:center;font-size:18px;background:#F0F0F0;color:#333}\n\n        #save a {text-decoration:none;color:white;font-size:inherit;color:#666}\n\n        #save p { margin: 0; padding: 0; margin-top: 8px}\n\n        #reload {position:absolute;z-index:9999;top:240px;left:8px;width:210px;height:36px;\n                 border-radius: 4px; border: solid 1px #ccc; padding: 5px;\n                 text-align:center;font-size:18px;background:#F0F0F0;color:#333}\n\n        #reload a {text-decoration:none;color:white;font-size:inherit;color:#666}\n\n        #reload p { margin: 0; padding: 0; margin-top: 8px}\n\n\n        #saveastro {position:absolute;z-index:9999;top:360px;left:8px;width:230px;height:70px;\n                    border-radius: 4px; border: solid 1px #ccc; background: white; text-align:center}\n        #saveastro p { margin: 0; padding: 0; margin-top: 16px}\n        \n        \n        #donate {position:absolute;z-index:9999;top:170px;right:16px;width:220px;height:36px;\n                 border-radius: 4px; border: solid 1px #ccc; padding: 5px;\n                 text-align:center;font-size:18px;background:white;color:#333}\n        \n        #donate a {text-decoration:none;color:green;font-size:inherit}\n\n        #donatein {position:absolute;z-index:9999;top:220px;right:16px;width:220px;height:36px;\n                 border-radius: 4px; border: solid 1px #ccc; padding: 5px;\n                 text-align:center;font-size:18px;background:green;color:#333}\n\n        #donatein a {text-decoration:none;color:white;font-size:inherit}\n        \n        #banner {position:absolute;z-index:9999;top:50%;left:45px;width:250px;height:250px; padding: 0; border: solid 1px white; border-radius: 4px}\n        \n    </style>\n    \n        \n    \n    <script type = "text/javascript">\n        window.onload = function() {\n            var url = document.getElementById(\'url\');\n            if (url.innerHTML.length > 77)\n                url.innerHTML = url.innerHTML.substring(0,77) + \'...\';\n        };\n    </script>\n    <div id = "top">\n        \n        <p class="agitation" style = "padding-top:12px">\n            \xd0\xa1\xd1\x82\xd1\x80\xd0\xb0\xd0\xbd\xd0\xb8\xd1\x87\xd0\xba\xd0\xb0 \xd0\xbf\xd1\x80\xd0\xbe\xd0\xb5\xd0\xba\xd1\x82\xd0\xb0 Sci-Hub \xd0\xb2 \xd1\x81\xd0\xbe\xd1\x86\xd0\xb8\xd0\xb0\xd0\xbb\xd1\x8c\xd0\xbd\xd1\x8b\xd1\x85 \xd1\x81\xd0\xb5\xd1\x82\xd1\x8f\xd1\x85 \xe2\x86\x92  <a target="_blank" href="https://vk.com/sci_hub">vk.com/sci_hub</a>\n        </p>\n        \n    </div>\n    \n    <div id = "content">\n        <iframe src = "http://moscow.sci-hub.io/202d9ebdfbb8c0c56964a31b2fdfe8e9/roerdink2016.pdf" id = "pdf"></iframe>\n    </div>\n    \n    <div id = "donate">\n        <p><a target = "_blank" href = "//sci-hub.io/donate">\xd0\xbf\xd0\xbe\xd0\xb4\xd0\xb4\xd0\xb5\xd1\x80\xd0\xb6\xd0\xb0\xd1\x82\xd1\x8c \xd0\xbf\xd1\x80\xd0\xbe\xd0\xb5\xd0\xba\xd1\x82 &rarr;</a></p>\n    </div>\n    <div id = "donatein">\n        <p><a target = "_blank" href = "//sci-hub.io/donate">support the project &rarr;</a></p>\n    </div>\n    <div id = "save">\n        <p><a href = # onclick = "location.href=\'http://moscow.sci-hub.io/202d9ebdfbb8c0c56964a31b2fdfe8e9/roerdink2016.pdf?download=true\'">\xe2\x87\xa3 \xd1\x81\xd0\xbe\xd1\x85\xd1\x80\xd0\xb0\xd0\xbd\xd0\xb8\xd1\x82\xd1\x8c \xd1\x81\xd1\x82\xd0\xb0\xd1\x82\xd1\x8c\xd1\x8e</a></p>\n    </div>\n    <div id = "reload">\n        <p><a href = "//sci-hub.io/reload/10.1016/j.anai.2016.01.022" target = "_blank">&#8635; \xd1\x81\xd0\xba\xd0\xb0\xd1\x87\xd0\xb0\xd1\x82\xd1\x8c \xd0\xb7\xd0\xb0\xd0\xbd\xd0\xbe\xd0\xb2\xd0\xbe</a></p>\n    </div>\n    \n        \n<!-- Yandex.Metrika counter --> <script type="text/javascript"> (function (d, w, c) { (w[c] = w[c] || []).push(function() { try { w.yaCounter10183018 = new Ya.Metrika({ id:10183018, clickmap:true, trackLinks:true, accurateTrackBounce:true, ut:"noindex" }); } catch(e) { } }); var n = d.getElementsByTagName("script")[0], s = d.createElement("script"), f = function () { n.parentNode.insertBefore(s, n); }; s.type = "text/javascript"; s.async = true; s.src = "https://mc.yandex.ru/metrika/watch.js"; if (w.opera == "[object Opera]") { d.addEventListener("DOMContentLoaded", f, false); } else { f(); } })(document, window, "yandex_metrika_callbacks"); </script> <noscript><div><img src="https://mc.yandex.ru/watch/10183018?ut=noindex" style="position:absolute; left:-9999px;" alt="" /></div></noscript> <!-- /Yandex.Metrika counter -->\n    </body>\n</html>\n'

其中包含网址,但我不确定如何提取网址。

更新

我现在能够提取URL但是当我尝试使用PDF访问页面时(通过urllib.request),即使URL有效,我也会收到403响应。关于为什么以及如何修复的任何想法? (我可以通过浏览器访问,因此不会阻止IP)

4 个答案:

答案 0 :(得分:1)

您可以使用urllib library访问网页的html,甚至可以下载文件,regex可以找到要下载的文件的网址。

import urllib
import re    

site = urllib.urlopen(".../index.html")
data = site.read() # turns the contents of the site into a string
files = re.findall('(http|https):\/\/([\w_-]+(?:(?:\.[\w_-]+)+))([\w.,@?^=%&:/~+#-]*[\w@?^=%&/~+#-])?(.pdf)', data) # finds the url

for file in files:
    urllib.urlretrieve(file, filepath) # "filepath" is where you want to save it 

答案 1 :(得分:0)

以下是解决方案: -

url = re.search('<iframe src = "\s*([^"]+)"', res.content)
url.group(1)
urllib.urlretrieve(url.group(1),'C:/.../Docs/test.pdf')

我跑了它并且它正在工作:)

对于Python 3:

urrlib.urlretrive更改为urllib.request.urlretrieve

答案 2 :(得分:0)

您可以使用需要硒,请求和scrapy的笨重代码来完成。

使用selenium请求文章标题或DOI。

private void newEvent(String name) {
    Event newEvent = new Event(name);
    // Copy the list
    List<Instructor> instructors = new ArrayList<>(currentInstructors);
    // Set that list
    newEvent.setInstructors(instructors);
    currentEvents.add(newEvent);
    // Now clearing this list won't clear the newEvent list
    currentInstructors.clear();
}

标题为“惊人的科学结果”的文章似乎并不存在。因此,该站点在浏览器窗口中返回一个我们可以忽略的诊断页面。它还将'http://sci-hub.io/'放在webdriver的>>> from selenium import webdriver >>> driver.get("http://sci-hub.io/") >>> input_box = driver.find_element_by_name('request') >>> input_box.send_keys('amazing scientific results\n') 属性中。这很有用,因为它表明请求的结果不可用。

current_url

让我们再试一次,寻找你认识的物品。

>>> driver.current_url
'http://sci-hub.io/'

这次网站返回一个独特的网址。不幸的是,如果我们使用selenium加载它,我们将得到pdf,除非你比我更能,否则你会发现很难将它下载到你机器上的文件中。

相反,我使用请求库下载它。在此表单中加载,您会发现PDF格式的网址在HTML中可见。

>>> driver.get("http://sci-hub.io/")
>>> input_box = driver.find_element_by_name('request')
>>> input_box.send_keys('DOI: 10.1016/j.anai.2016.01.022\n')
>>> driver.current_url
'http://sci-hub.io/10.1016/j.anai.2016.01.022'

为了找出我使用scrapy的网址。

>>> import requests
>>> r = requests.get(driver.current_url)

最后,我再次使用请求下载pdf,以便将其保存到本地存储上方便命名的文件中。

>>> from scrapy.selector import Selector
>>> selector = Selector(text=r.text)
>>> pdf_url = selector.xpath('.//iframe/@src')[0].extract()

答案 3 :(得分:0)

我使用上述答案的组合解决了这个问题 - 即 SBO7 &amp;的 Roxerg

我使用以下内容从页面中提取URL,然后下载PDF:

    res = requests.get('http://sci-hub.io/' + str(row['DOI']))
    useful = BeautifulSoup(res.content, "html5lib").find_all("iframe")
    urls = re.findall('http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\(\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+', str(useful[0]))
    response = requests.get(urls[0])
    with open("C:\\Users\\Sangeeta's\\Downloads\\ref\\" + str(row['ref']) + '.pdf', 'wb') as fw:
        fw.write(response.content)

注意: 这对所有文章都不起作用 - 有些链接到网页(example),这对那些文章无效