使用 python 从网站上抓取 excel，并隐藏 _doPostBack 链接 url

在过去的几天里，我试图废弃以下网站（链接粘贴在下面），该网站在表格中提供了一些 Excel 和 pdf。我能够成功地为主页做到这一点。这些 excel/pdf 总共有 59 页需要废弃。到目前为止，在我见过的大多数网站中，网站 URL 中都有一个可用的查询参数，当您从一个页面移动到另一页面时，该参数会发生变化。在本例中，我们有一个 _doPostBack 函数，可能是因为该函数在您访问的每个页面上的 URL 都保持相同。我查看了多个解决方案和帖子，建议查看以下参数post调用并使用它们，但我无法理解中提供的参数post打电话（这是我第一次抓取网站）。

有人可以建议一些资源来帮助我编写一段代码，帮助我使用 python 从一个页面移动到另一个页面。详情如下所示：

网站链接-http://accord.fairfactories.org/ffcweb/Web/ManageSuppliers/InspectionReportsEnglish.aspx http://accord.fairfactories.org/ffcweb/Web/ManageSuppliers/InspectionReportsEnglish.aspx

我当前的代码从主页提取 CAP excel 表（这工作完美，仅供参考）

from urllib.request import urlopen
from urllib.request import urlretrieve
from bs4 import BeautifulSoup
import re
import urllib

Base = "http://accord.fairfactories.org/ffcweb/Web"
html = urlopen("http://accord.fairfactories.org/ffcweb/Web/ManageSuppliers/InspectionReportsEnglish.aspx")
bs = BeautifulSoup(html)
name = bs.findAll("td", {"class":"column_style_right column_style_left"})
i = 1
for link in bs.findAll("a", {"id":re.compile("CAP(?!\w)")}):
    if 'href' in link.attrs:
        name = str(i)+".xlsx"
        a = link.attrs['href']
        b = a.strip("..")
        c = Base+b
        urlretrieve(c, name)
        i = i+1

如果我在提供信息时遗漏了任何内容，请告诉我，并且请不要评价我 - 否则我将无法进一步询问任何问题

对于 aspx 网站，您需要寻找类似的内容__EVENTTARGET, __EVENTVALIDATION等等..并在每个请求中发布这些参数，这将获取所有页面并使用requests http://docs.python-requests.org/en/master/ with bs4:

import requests
from bs4 import BeautifulSoup
from urlparse import urljoin # python 3 use from urllib.parse import urljoin   



# All the keys need values set bar __EVENTTARGET, that stays the same.
data = {
    "__EVENTTARGET": "gvFlex",
    "__VIEWSTATE": "",
    "__VIEWSTATEGENERATOR": "",
    "__VIEWSTATEENCRYPTED": "",
    "__EVENTVALIDATION": ""}


def validate(soup, data):
    for k in data:
        # update post values in data.
        if k != "__EVENTTARGET":
            data[k] = soup.select_one("#{}".format(k))["value"]


def get_all_excel():
    base = "http://accord.fairfactories.org/ffcweb/Web"
    url = "http://accord.fairfactories.org/ffcweb/Web/ManageSuppliers/InspectionReportsEnglish.aspx"
    with requests.Session() as s:
        # Add a user agent for each subsequent request.
        s.headers.update({"User-Agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0"})
        r = s.get(url)
        bs = BeautifulSoup(r.content, "lxml")
        # get links from initial page.
        for xcl in bs.select("a[id*=CAP]"):
            yield urljoin(base, xcl["href"])
        # need to re-validate the post data in our dict for each request.
        validate(bs, data)
        last = bs.select_one("a[href*=Page$Last]")
        i = 2
        # keep going until the last page button is not visible
        while last:
            # Increase the counter to set the target to the next page
            data["__EVENTARGUMENT"] = "Page${}".format(i)
            r = s.post(url, data=data)
            bs = BeautifulSoup(r.content, "lxml")
            for xcl in bs.select("a[id*=CAP]"):
                yield urljoin(base, xcl["href"])
            last = bs.select_one("a[href*=Page$Last]")
            # again re-validate for next request
            validate(bs, data)
            i += 1


for x in (get_all_excel()):
    print(x)

如果我们在前三页运行它，你可以看到我们得到了你想要的数据：

http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9965
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9552
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10650
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11969
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10086
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10905
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10840
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9229
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11310
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9178
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9614
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9734
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10063
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10871
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9468
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9799
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9278
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=12252
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9342
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9966
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11595
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9652
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10271
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10365
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10087
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9967
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11740
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=12375
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11643
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10952
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=12013
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9810
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10953
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10038
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9664
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=12256
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9262
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9210
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9968
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9811
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11610
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9455
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11899
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10273
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9766
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9969
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10088
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10366
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9393
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9813
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11795
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9814
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11273
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=12187
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10954
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9556
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11709
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9676
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10251
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10602
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10089
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9908
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10358
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9469
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11333
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9238
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9816
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9817
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10736
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10622
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9394
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9818
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=10592
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=9395
http://accord.fairfactories.org/Utilities/DownloadFile.aspx?id=11271