使用Python或其他方法从PDF中提取指向另一个PDF中页面的链接

Question

我有5个PDF文件，每一个都有链接到另一个PDF文件中的不同页面。这些文件都是大型PDF的目录（每个大约1000页），使得手动提取成为可能，但非常痛苦。到目前为止，我已经尝试在Acrobat Pro中打开该文件，我可以右键单击每个链接并查看它指向的页面，但我需要以某种方式提取所有链接。我不反对对链接进行大量的进一步解析，但我似乎无论如何也无法将它们拔出。我试图从acrobatpro导出PDF为HTML或Word，但两种方法都没有维护链接。在

我束手无策，任何帮助都会很好。我很喜欢使用Python或其他一系列语言

Answer 1

使用pyPdf查找uri

import pyPdf

f = open('TMR-Issue6.pdf','rb')

pdf = pyPdf.PdfFileReader(f)
pgs = pdf.getNumPages()
key = '/Annots'
uri = '/URI'
ank = '/A'

for pg in range(pgs):

    p = pdf.getPage(pg)
    o = p.getObject()

    if o.has_key(key):
        ann = o[key]
        for a in ann:
            u = a.getObject()
            if u[ank].has_key(uri):
                print u[ank][uri]

给予

^{pr2}$

我找不到有指向另一个pdf的链接的文件，但我怀疑URI字段应该包含格式为file:///myfiles的URI

Answer 2

我刚刚为此制作了一个小Python工具，从给定的PDF中列出/下载所有引用的PDF:https://www.metachris.com/pdfx/（也可以是：https://github.com/metachris/pdfx）

$ ./pdfx.py https://weakdh.org/imperfect-forward-secrecy.pdf -d ./
Reading url 'https://weakdh.org/imperfect-forward-secrecy.pdf'...
Saved pdf as './imperfect-forward-secrecy.pdf'
Document infos:
- CreationDate = D:20150821110623-04'00'
- Creator = LaTeX with hyperref package
- ModDate = D:20150821110805-04'00'
- PTEX.Fullbanner = This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013/Debian) kpathsea version 6.1.1
- Producer = pdfTeX-1.40.14
- Title = Imperfect Forward Secrecy: How Diffie-Hellman Fails in Practice
- Trapped = False
- Pages = 13

Analyzing text...
- URLs: 49
- URLs to PDFs: 17

JSON summary saved as './imperfect-forward-secrecy.pdf.infos.json'

Downloading 17 referenced pdfs...
Created directory './imperfect-forward-secrecy.pdf-referenced-pdfs'
Downloaded 'http://cr.yp.to/factorization/smoothparts-20040510.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/smoothparts-20040510.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35517.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35517.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35514.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35514.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35519.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35519.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35522.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35522.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35509.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35509.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35528.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35528.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35513.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35513.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35533.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35533.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35551.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35551.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35527.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35527.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35520.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35520.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35526.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35526.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35515.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35515.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35529.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35529.pdf'...
Downloaded 'http://cryptome.org/2013/08/spy-budget-fy13.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/spy-budget-fy13.pdf'...
Downloaded 'http://www.spiegel.de/media/media-35671.pdf' to './imperfect-forward-secrecy.pdf-referenced-pdfs/media-35671.pdf'...

该工具使用PyPDF2（事实上的Python标准库）来读取PDF内容，regular expression to match all urls，如果使用-d选项（对于 download-pdfs）运行它，它会为每个PDF启动一个下载线程。在