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django/python: How to convert pptx/docx formats to PDF using python?

First of all, I agree that this might sound like a question which has already been asked many times in the past. However I couldn't find any answer that was relevant to me in the similar questions so I'll try to be more specific.
I would need to transform PPTX/DOCX files into PDF using Python but I don't have any experience in file format conversion. I have been looking in many places/forums/websites, read a lot of documentation and came across some useful libraries (python-pptx and pyPdf mainly), but I still don't know where to start.
When looking on the Internet, I can see many websites that offer file format conversions as a paying service, even with advanced API's: submit a file via POST and get the transformed PDF file in return. This could work for me, but I am really interested in writing myself the code that does the conversion work from OOXML to PDF.
How would you start doing this? Or is it just impossible on my own?
Thanks for your help!

After some research and with the help of python-pptx's creator, I was able to write to the PowerPoint COM interface using a Virtual Machine.
In case someone reads this thread, this is how I managed to get this done:
- Setup a VM with Microsoft Windows/Office installed on it ;
- Install Python, Django and win32com libraries on the VM.
The files are sent locally from the original Django project to the virtual machine (which are on the same network) through a simple POST request. The file is converted on the VM using win32com.client (which is just a simple call to the win32com.client library) and then sent back as a response to the original Django view, which in turn processes the response.
Note: it took me some time to realize I needed to use the #csrf_exempt decorator for this setup to work.

VRML to X3D Conversion

I'm working on a web application that manages VRML files. I also want to let users see the uploaded files, without requiring a specific plug-in or player. X3DOM allows viewing X3D files without plug-ins on most browsers, so I'd like to use it.
Alas, it works on X3D files, and not VRML files. I need to convert VRML files to the X3D format.
The same people behind X3DOM released a package called InstantReality that has a utility that converts VRML to X3D. However, I'd much rather not use an external utility (I'm not even sure I'm allowed to use it on a commercial environment, I couldn't find its terms of use) but call a conversion routine from my application code.

MeshLab! There's an opensource project called MeshLab that does all sorts of processing on 3D meshes. It also has a command-line tool called MeshlabServer.
Running meshlabserver.exe -i <wrl file> -o <x3d file> performs the conversion (very quickly). Since it's open-source, I don't have any licensing issues.

are you talking about this online converter?
http://doc.instantreality.org/tools/x3d_encoding_converter/
you could probably build some scripting to convert the vrml to x3d/x3dom and then store and or display
as well blender aopt and others should be able to convert vrml to x3d on the command line. depending on your servers os this could be batched/scripted as well
im in a rush to get some other work done but hope this helps.
let me know if you need more info or examples and ill see what i can do

I also needed to convert VRML .wrl to .x3d; I tried meshlab (meshlabserver), but unfortunately, the version I have (.deb 2016.12~trusty2 on Ubuntu 14.04) compacts everything to a single mesh, and looses color in the process.
I found that view3dscene can do conversion from the command line, where the materials/colors are preserved in .x3d, as they were in .wrl:
view3dscene mymodel.wrl --write --write-encoding xml > mymodel.x3d
Since view3dscene functions as a viewer for both .wrl and .x3d files, it can also be used immediately, to check if the converted (or the original) file has colors or not.

ok so i think this is the full solution for you
1) user uploads a vrml file
2) that file gets saved to (file or db)
3) upon confirmation that the vrml file has been saved (and possibly validated as correct vrml syntax) it gets converted and saved to x3d (again as file or db) , with aopt this would be accomplished by aopt -i input.wrl -o output.x3d
FYI: aopt is avail for linux windows and mac
since you use python this maybe a way you could do it as well with blender although there are no full example of vrml to x3d this link should get you started
http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Import-Export/Wavefront_OBJ#Command_Line_Converting
4) display the x3d via x3dom

Since the ClassicVRML X3D Encoding is a direct successor of the VRML97 standard, in most cases you can copy the file, rename the .wrl file extension to a .x3dv file extension, and change the scene header from
#VRML V2.0 utf8
to
#VRML V3.3 utf8
PROFILE Immersive
Many converters exist, both commercial and open source. Several are integrated with X3D-Edit. A full list is maintained at
X3D Resources: Conversions and Translation Tools
http://www.web3d.org/x3d/content/examples/X3dResources.html#Conversions
Personal favorite:
Castle Game Engine: Convert everything to X3D
https://castle-engine.io/convert.php

If you simply want to convert X3D XML encoded files to VRML Classic encoded files you can use Titania, http://titania.create3000.de/. Open your .x3d file and save it as .x3dv or .wrl.
Titania also comes with a command line utitity »x3dtidy« that can do the conversion too.

You can use this tool (a java jar that can be run from the command line) to convert VRML to X3D:
http://www.deem7.com/vrmlmerge/howto.php
java -jar VrmlMerge-[version].jar -convert inputfile.wrl [outputfile.x3d]
The license:
VrmlMerge is free for non-commercial use. If you somehow make money out of VrmlMerge then I'd like you to contact me to agree on some terms of use. VrmlMerge is provided "as is" and I don't take any responsibility for any damage it can make to you, your computer, files, data, wife, brain etc..

Output PCL from Word document using Python

I'm building a web application which will include functionality that takes MS Word (and possibly input from a web-based rich text editor) documents, substitutes values into the formfield placeholders in those documents, and generates a PCL document as output.
I'm developing in python and django on windows, but this whole solution will need to be deployed to a web host (yet to be chosen), which in practice means that the solution will need to run on linux.
I'm open to linux-only solutions if that's the only way. I'm open to solutions that involve talking to a server written in another language. I am able to write C++ or java if necessary to get this done. The final output does have to be in PCL format.
My question is: what is a good tool chain for generating PCL from word documents using python?
I am considering using some kind of interface to openoffice to open the word documents, do the substitutions, and send the output to some kind of printer driver. Does anyone have experience with this? What libraries would you recommend?
Options for interfacing that I have identified include the following; any other suggestions would be greatly welcomed:
Ulif.openoffice: http://pypi.python.org/pypi/ulif.openoffice/0.4
Py3o.renderserver: https://bitbucket.org/faide/py3o.renderserver
OpenOffice-python: http://openoffice-python.origo.ethz.ch/
A second approach would be to use something like paradocx ( https://bitbucket.org/yougov/paradocx/wiki/Home ) to open the word files, do the substitutions using that in python, then somehow interface with something that can output PCL. Again, any experience or comments on this approach would be appreciated.
I will very much appreciate any comments on tools and toolchains, and ideas or recipes that you may have.
This question covers similar ground to, but is not the same as: How to Create PCL file from MS word

Ghostscript can read PS (Postscript) or PDF and create PCL. You can use python libraries or just subprocess....

OK, so my final solution involved creating a java webservice to perform my transcoding.
Docx4j provides a class org.docx4j.convert.out.pdf.viaXSLFO.Conversion which hooks into apache FOP to convert Docx to PDF; that can be easily hacked to convert to PCL (because FOP outputs PCL)
Spark is a lightweight java web framework which allowed me to wrap my transcoder in a web service
Because I also manipulate the document, I need to have some metadata, so the perfect thing is a multipart form. I decode that using Apache Fileupload
In almost all cases, I had to upgrade to the development versions of libraries to get this to work.
On the python side I use:
requests to communicate with the web service
poster to prepare the multi-part request

Any good pdf417 Barcode libraries for Python?

I'm looking for a good python module to generate pdf417 barcodes. Has anyone used one they liked?
Ideally I would like one with as few dependencies as possible, and one that runs on both linux and MacOSX.

We recently had to approach this problem as well, and being a Python shop we wanted a Python solution. It become clear the elaphe is the project that had the potential to actually accomplish pdf 417 barcode.
However what we found was it errors by todays standards, and so we entered the hunt to fix the library. Turns out elaphe must generate an outdated form of *.eps post script that can't be interpreted by ghost script and this is where the bar code generation fails.
Well fortunately elphae uses a common library behind the scenes called Barcode Writer in Pure PostScript # http://bwipp.terryburton.co.uk
This common backend library which has many projects in multi-languages using it to generate projects. The fix specifically for us was to fork elaphe, and correct it's *.eps file generation.
To determine what is broken in the *.eps, look at this other site that is made using postscriptbarcode, and it let's you generate the pdf417 barcode online (as well as other formats): http://www.terryburton.co.uk/barcodewriter/generator/
Once you generate a pdf417 barcode it gives you the option to download the .png, .jpg, and YES the .eps file!
Using this .eps file you can pipe it to ghost script and tweak the parameterization to get the exact pdf417 barcode you are looking for. Then take this result and integrate it into the elaphe library and actually get a pull request on that thing ....
Seems to be a bit of work, but nothing that can't be knocked out in an afternoon. It is ideal to get the elaphe library back in shape to generate these without making this enhancement.
Please note that the performance of this approach for us is a few seconds to generate this barcode due to the fact it creates the 2000 line eps file and pipes it to ghost script which generates another image file that we send back as the final barcode result. This is not as performance as code128 with reportlab.
Perhaps room for optimizations: Is pillow faster than PIL in anyway? Do we need all the parts of the eps file to generate the barcode of type pdf417? Other ways to optimize?
Anyway, great question Ken and I hope you find this to be a great answer.

I guess the issue in elaphe reported by Matteius in 2013 has been fixed, since the issues and commit logs show updates on the pdf417 topic since then.
Anyway, there are now a few other options (got the list with either pip search elaphe or pip search pdf417) :
elaphe ;
elaphe3 (fork of elaphe tested against python3) ;
candybar (no documentation ? also a webservice) ;
pdf417gen ;
treepoem (about the name : barcode -> bark ode -> tree poem =D ) — edit : didn't dig the issue, but as of today generation of PDF417 seems broken.
All but pdf417gen support several types of barcodes.
Note that the documentation of bwipp (on which are based elaphe and treepoem) only mentions 5 levels of error correction (1 to 5), while pdf417gen claims to support 9 security levels (0 to 8).

Reportlab does have an extension called rlbarcode, but this one does not include support for pdf417 codes. I do not know of any other extension for reportlab including support for pdf417 bar codes.
Anyway, if you are interested in generation of pdf417 codes from python, you may be interested in this project: elaphe.
I have still not tested it (in fact, I need to generate pdf417 from python, and I found this thread as well as the elaphe project page) I am going to download the elaphe tools in order to test it right now.

How do I create a set of image files from a PowerPoint file file?

I'm creating a "slideshow room" web page. The user will upload a PowerPoint file that my server will use to generate a set of .jpg image files representing the slides to present in a custom "gallery viewer".
I'm an experienced Python developer but I cannot find anything useful.
How can I do that?

Off the top of my head, the way I'd do it:
Use OpenOffice.org to convert the .ppt file into a PDF. (OO.o has a very rich Java API. Rich and bloody difficult to use, mind, but once you figure out how to get it to do the task you need, you're all set. Dunno if you can do anything useful with it via Python; not my language.)
Use ImageMagick to convert the PDF into .jpg files. (Though I've been told converting the PDF into a PS file before turning it into images gives better results.) (IM's command line interface is damn near a language unto itself -- though again, once you figure out how to get it to do what you want, you're all set.)
Dunno if that's the most efficient/reliable way to do it. But fundamentally, I'd be on Google trolling for open-source third party tools that do all the dirty work for me.

Apache POI and Jython. POI, even has an ImageExtractor class, but having just glanced at the Javadocs, I suspect it is incomplete.

Are you doing this on Windows? If so win32 com:
import win32com.client
Application = win32com.client.Dispatch("PowerPoint.Application")
Application.Visible = True
Presentation = Application.Presentations.Open(pathToPPT)
Presentation.Slides[1].Export("C:/path/to/jpg.jpg", "JPG", 800, 600);
etc...