Re:Show HN: I am building a new Python library to read/write...
by layer8 on Thursday November 17, 2022 @09:31PM
(#33649120)
1. PDF is mostly designed as a write-only (or render-only) format. Itβs original purpose was as a device-independent page description language for printers, because PostScript documents at the time were specific to the targeted printer model.
2. Many PDF documents do not conform to the PDF specification in a multitude of ways, yet Adobe Acrobat Reader accepts them, and so PDF parsers have to implement a lot of kludgy logic accordingly.
3. The format has grown to be quite complex, with a lot of features added over the years. Implementing a parser even for spec-compliant PDFs is a decidedly nontrivial effort.
So PDF is a reasonably good output format for fixed-layout pages for display and especially for print, but a really bad input format.
2. Many PDF documents do not conform to the PDF specification in a multitude of ways, yet Adobe Acrobat Reader accepts them, and so PDF parsers have to implement a lot of kludgy logic accordingly.
3. The format has grown to be quite complex, with a lot of features added over the years. Implementing a parser even for spec-compliant PDFs is a decidedly nontrivial effort.
So PDF is a reasonably good output format for fixed-layout pages for display and especially for print, but a really bad input format.