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Cake day: June 23rd, 2023

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  • PyMuPDF is excellent for extracting ‘structured’ text from a pdf page — though I believe ‘pulling out relevant information’ will still be a manual task, UNLESS the text you’re working with allows parsing into meaningful units.

    That’s because ‘textual’ content in a pdf is nothing other than a bunch of instructions to draw glyphs inside a rect that represents a page; utilities that come with mupdf or poppler arrange those glyphs (not always perfectly) into ‘blocks’, ‘lines’, and ‘words’ based solely on whitespace separation; the programmer who uses those utilities in an end-user facing application then has to figure out how to create the illusion (so to speak) that the user is selecting/copying/searching for paragraphs, sentences, and so on, in proper reading order.

    PyMuPDF comes with a rich collection of convenience functions to make all that less painful; like dehyphenation, eliminating superfluous whitespace, etc. but still, need some further processing to pick out humanly relevant info.

    Built-in regex capabilities of Python can suffice for that parsing; but if not, you might want to look into NLTK tools, which apply sophisticated methods to tokenize words & sentences.

    EDIT: I really should’ve mentioned some proper full text search tools. Once you have a good plaintext representation of a pdf page, you might want to feed that representation into tools like the following to index them properly for relevant info:

    https://lunr.readthedocs.io/en/latest/ – this is easy to use, & set up, esp. in a python project.

    … it’s based on principles that are put to use in this full-scale, ‘industrial strength’ full text search engine: https://solr.apache.org/ – it’s a bit of a pain to set up; but python can interface with it through any http client. Once you set up some kind of mapping between search tokens/keywords/tags, the plaintext page, & the actual pdf, you can get from a phrase search, for example, to a bunch of vector graphics (i.e. the pdf) relatively painlessly.




  • Another vote for Tesseract – just to clarify the terminology, though: PDF is a fragile format best used read-only; so you really don’t want to edit a pdf, but make a new one using the same (or cleaned-up) bitmaps and a new ocr text layer.

    Now, tesseract is excellent at recognizing glyphs; but especially if the scanned image is a little fuzzy, the layout detection falters; and when it falters, you get redundant line breaks, & chunks of text in the wrong order – all of which gets incredibly annoying for searching & copying purposes. So if you can spare the time, and the text requires it, you may need to mark regions (paragraphs & titles mainly) on the bitmap image manually. There exist a few frontends to Tesseract that help with a task like that; check out, e.g., https://github.com/manisandro/gImageReader - inside single paragraph blocks of text, Tesseract doesn’t get as easily confused; and the text output is in the correct reading order, & w/o redundant breaks.



  • Yeah I keep running into similar issues when trying to build pretty much anything on windows; for stuff that can’t be ‘nicely’ configured & dependency-managed through an IDE, windows is pure pain.

    It really sounds like PySide would fit your use case better. Check out this website for a great starting point: https://www.pythonguis.com/pyqt6/ – the author also has an entire book on packaging PySide programs for cross-platform distribution.

    As for installing Python itself; I think I’d stick with the plain installer from python.org, and afterwards, pip. In case of dependencies that are hard to get through PyPi, I think anaconda might be worth looking at as well: https://www.anaconda.com/download

    msys2 provides a package manager, & several development toolchains; it’s an easy way to get native (mingw) gcc & bash on windows; cross-platform programs rely on it heavily, because it saves them from all the ‘visual studio’ BS: https://www.msys2.org/docs/what-is-msys2/ – I believe any implementation of GTK on windows requires a mingw toolchain.


  • Am I missing something?

    It’s impossible to tell without knowing what specific aspect had failed.

    Before we even get to GTK; there are some issues with python wheels under msys2; check out: https://www.msys2.org/docs/python/ – some wheels just can’t be built under msys2 due to various incompatibilities. Not being able to replace such packages with ‘pure’ python equivalents could end up being a (very annoying) roadblock.

    The roadblock that I recently ran into with my simple GTK4 app was unpredictable ids on d-bus interface exports. D-bus does work under msys2; though you have to start the user session manually; d-feet and gdbus also work; though, as always, there’s a catch. On Linux I can automaticaly export ‘action groups’ that belong to GtkApplicationWindow widgets; & their 'object path’s show up predictably under the application’s path + / + the window’s id. This makes it really convenient when you want to add basic ‘remote controls’ to your widgets. Under msys2, though, I can’t figure out how to find those paths; which throws a monkey wrench, so to speak, in my ‘remote control’ implementation. Granted, d-bus is a linux-native technology; and expecting it to work w/o issues on windows is probably a bit too much.

    – apart from those, I haven’t run into any issues with GTK4 under msys2. The GTK3 packages available in their repos also work just fine.

    I do agree with the others who recommend PySide, though. Their cross platform support appears to be more robust. Their documentation has been improving as well.