使用 Python 下载网页上的所有链接（相关文档）

Question

我必须从网页下载大量文档。它们是 wmv 文件、PDF、BMP 等。当然，它们都有指向它们的链接。所以每次，我都必须 RMC 一个文件，选择“将链接另存为”，然后保存为所有文件类型。是否有可能在 Python 中做到这一点？我搜索了 SO DB，人们已经回答了如何从网页获取链接的问题。我想下载实际文件。提前致谢。 （这不是硬件问题:)）。

Answer 1

• 遵循此链接中的 Python 代码：wget-vs-urlretrieve-of-python。
• 您也可以使用Wget 轻松完成此操作。在Wget 中尝试--limit、--recursive 和--accept 命令行。例如： wget --accept wmv,doc --limit 2 --recursive http://www.example.com/files/

Answer 2

这是一个示例，说明如何从 http://pypi.python.org/pypi/xlwt 下载一些选定的文件

你需要先安装mechanize：http://wwwsearch.sourceforge.net/mechanize/download.html

import mechanize
from time import sleep
#Make a Browser (think of this as chrome or firefox etc)
br = mechanize.Browser()

#visit http://stockrt.github.com/p/emulating-a-browser-in-python-with-mechanize/
#for more ways to set up your br browser object e.g. so it look like mozilla
#and if you need to fill out forms with passwords.

# Open your site
br.open('http://pypi.python.org/pypi/xlwt')

f=open("source.html","w")
f.write(br.response().read()) #can be helpful for debugging maybe

filetypes=[".zip",".exe",".tar.gz"] #you will need to do some kind of pattern matching on your files
myfiles=[]
for l in br.links(): #you can also iterate through br.forms() to print forms on the page!
    for t in filetypes:
        if t in str(l): #check if this link has the file extension we want (you may choose to use reg expressions or something)
            myfiles.append(l)


def downloadlink(l):
    f=open(l.text,"w") #perhaps you should open in a better way & ensure that file doesn't already exist.
    br.click_link(l)
    f.write(br.response().read())
    print l.text," has been downloaded"
    #br.back()

for l in myfiles:
    sleep(1) #throttle so you dont hammer the site
    downloadlink(l)

注意：在某些情况下，您可能希望将 br.click_link(l) 替换为 br.follow_link(l)。不同之处在于 click_link 返回一个 Request 对象，而 follow_link 将直接打开链接。见Mechanize difference between br.click_link() and br.follow_link()