Develop Reference

Creating PDFs from HTML/Javascript in Python with no OS dependencies

Is there any way to use Python to create PDF documents from HTML/CSS/Javascript, without introducing any OS-level dependencies?
It seems every existing solution requires special supplemental software, but upon reviewing PDF formatting specifications and HTML/CSS/Javascript rendering, there doesn't appear to be a reason why a Python solution can't exist without them. Some solutions come close, such as pyppeteer, but it still leans on a headless Chrome installation locally. These dependencies mean that microservices can't be leveraged, even though PDF generation would otherwise seem to be a viable use case for them.
While similar questions have come up many times over on SO, there doesn't appear to have been a viable technique shown without having to install specialized dependencies on the OS.
Some similar questions which routinely recommend wkhtmltopdf or are otherwise out of date (e.g., moving PDF printing support outside of Chrome is dead now):
How to convert webpage into PDF by using Python
How to convert a local HTML file to PDF using Python in Windows
HTML to PDF conversion using Chrome pdfium
How does Chrome render PDFs from HTML so well?
Convert a HTML/CSS/Javascript file to PDF using Python?
If I've somehow missed a viable approach, please feel free to mark this as a duplicate with my thanks!
Edit February 2021: It appears that the cefpython project may meet these demands - PDF printing support seems like it could be implemented in the near future.

So to clarify and formalize what others have said:
If you want to create PDF documents from HTML/CSS/javascript content, you will necessarily need a javascript engine (because you obviously need to execute the javascript if it affects the visuals of the document). This is the most complex component that you need.
As for now, there is no ECMAscript compliant engine written in pure python that is well-maintained (that would be a huge project)... There will probably never be one, since compilers and VMs for languages need to be performant and are thus usually written in a performant low-level language.
So you will always need compiled binaries for that and the HTML renderers which are less complex but also need to be performant if used in browsers, so usually they're also C++ or the likes.
The javascript engine and HTML renderer are the major part of a browser, so a headless browser is a good solution to this requirement.

Try this library: xhtml2pdf
It worked for me. Here is the documentation: doc
Some sample code:
from xhtml2pdf import pisa
def convert_html_to_pdf(source_html, output_filename):
# open output file for writing (truncated binary)
result_file = open(output_filename, "w+b")
# convert HTML to PDF
pisa_status = pisa.CreatePDF(
source_html, # the HTML to convert
dest=result_file) # file handle to recieve result
# close output file
result_file.close() # close output file
# return False on success and True on errors
return pisa_status.err
# Define your data
source_html = open('2020-06.html')
output_filename = "test.pdf"
convert_html_to_pdf(source_html, output_filename)

Converting HTML to Excel with Django

I have a reporting module in my Django app that gives the user the ability to see their reports on screen or to export them and have the export opened by Excel.
The export is a cheat. I take the exact same output as the screen version and save it to a file with an .xls extension and
response = HttpResponse(body, content_type='application/vnd.ms-excel')
and badda-boom, badda-bing I have an Excel file that is lightly formatted, i.e. it respects the css styling that I've applied.
The nice thing for the user is that the file auto-opens in Excel; there aren't any extra steps for them. (find the download, import a text file, etc.)
Unfortunately it looks like Excel 2016 has decided (I'm guessing) that that's a security issue and no longer opens the file.
I'm aware of various python -> Excel tools. openpyxl looks promising. But that's going to require me to touch each report.
So, what I'm looking for is something that would give me what I have now, take an html file and have Excel open it as a native file and recognize the existing formatting.

The behavior change has been noted by Microsoft and there are work arounds, for the user:
https://support.microsoft.com/en-us/kb/3181507
It sounds like they're working on a fix.

Generating correct excel xls format

I created a little script in python to generate an excel compatible xml file (saved with xls extension). The file is generated from a part database so I can place an order with the extracted data.
On the website for ordering the parts, you can import the excel file so the order fills automatically. The problem here is that each time I want to make an order, I have to open excel and save the file with xls extension of type MS Excel 97-2003 to get the import working.
The excel document then looks exactly the same, but when opened with notepad, we cannot see the xml anymore, only binary dump.
Is there a way to automate this process, by running a bat file or maybe adding some line to my python script so it is converted in the proper format?
(I know that question has been asked before, but it never has been answered)

There are two basic approaches to this.
You asked about the first: Automating Excel to open and save the file. There are in fact two ways to do that. The second is to use Python tools that can create the file directly in Python without Excel's help. So:
1a: Automating Excel through its automation interface.
Excel is designed to be controlled by external apps, through COM automation. Python has a great COM-automation interface inside of pywin32. Unfortunately, the documentation on pywin32 is not that great, and all of the documentation on Excel's COM automation interface is written for JScript, VB, .NET, or raw COM in C. Fortunately, there are a number of questions on this site about using win32com to drive Excel, such as this one, so you can probably figure it out yourself. It would look something like this:
import win32com.client
excel = win32com.client.Dispatch('Excel.Application')
spreadsheet = excel.Workbooks.Open('C:/path/to/spreadsheet.xml')
spreadsheet.SaveAs('C:/path/to/spreadsheet.xls', fileformat=excel.xlExcel8)
That isn't tested in any way, because I don't have a Windows box with Excel handy. And I vaguely remember having problems getting access to the fileformat names from win32com and just punting and looking up the equivalent numbers (a quick google for "fileformat xlExcel8" shows that the numerical equivalent is 56, and confirms that's the right format for 97-2003 binary xls).
Of course if you don't need to do it in Python, MSDN is full of great examples in JScript, VBA, etc.
The documentation you need is all on MSDN (since the Office Developer Network for Excel was merged into MSDN, and then apparently became a 404 page). The top-level page for Excel is Welcome to the Excel 2013 developer reference (if you want a different version, click on "Office client development" in the navigation thingy above and pick a different version), and what you mostly care about is the Object model reference. You can also find the same documentation (often links to the exact same webpages) in Excel's built-in help. For example, that's where you find out that the Application object has a Workbooks property, which is a Workbooks object, which has Open and Add methods that return a Workbook object, which has a SaveAs method, which takes an optional FileFormat parameter of type XlFileFormat, which has a value xlExcel8 = 56.
As I implied earlier, you may not be able to access enumeration values like xlExcel8 for some reason which I no longer remember, but you can look the value up on MSDN (or just Google it) and put the number 56 instead.
The other documentation (both here and elsewhere within MSDN) is usually either stuff you can guess yourself, or stuff that isn't relevant from win32com. Unfortunately, the already-sparse win32com documentation expects you to have read that documentation—but fortunately, the examples are enough to muddle your way through almost everything but the object model.
1b: Automating Excel via its GUI.
Automating a GUI on Windows is a huge pain, but there are a number of tools that make it a whole lot easier, such as pywinauto. You may be able to just use swapy to write the pywinauto script for you.
If you don't need to do it in Python, separate scripting systems like AutoIt have an even larger user base and even more examples to make your life easier.
2: Doing it all in Python.
xlutils, part of python-excel, may be able to do what you want, without touching Excel at all.

Script to search for text from PDF

Problem
On the Mac OS X platform, I would like to write a script, either in Python or Tcl to search for text within a PDF file and extract the relevant parts. I appreciate any help.
Background
I am writing scripts to look inside a PDF to determine if it is a bill, from what company, and for what period. Based on these information, I rename the PDF and move it to an appropriate directory. For example, file such as Statement_03948293929384.pdf might become 2012-07-15 Water Bill.pdf and moved to my Utilities folder.
What have I done so far?
I have searched for PDF-to-plain-text tools, but not found anything yet
I have looked into the Tcl wiki and found an example, but could not get it to work (I searched for text in PDF, but not found).
I am looking into pdf-parser.py by Didier Stevens
I heard of a Python package called pyPdf and will look at it next.
Update
I have found a command-line tool called pdftotext written by Glyph & Cog, LLC; built and packaged by Carsten Bluem. This tool is straight forward and it solves my problem. I am still looking out for those tools that can search PDF directly, without having to convert to text file.

I have successfully used PyODConverter to convert to/from PDFs (there is also a more powerful Java version). Once you have the PDF converted to text it should be trivial to do the searching. Also I believe iText should be capable of doing similar things, but I haven't tested it.

What's a good document standard to use programmatically?

I'm writing a program that requires input in the form of a document, it needs to replace a few values, insert a table, and convert it to PDF. It's written in Python + Qt (PyQt). Is there any well known document standard which can be easily used programmatically? It must be cross platform, and preferably open.
I have looked into Microsoft Doc and Docx, which are binary formats and I can't edit them. Python has bindings for it, but they're only on Windows.
Open Office's ODT/ODF is zipped in an xml file, so I can edit that one but there's no command line utilities or any way to programmatically convert the file to a PDF. Open Office provides bindings, but you need to run Open Office from the command line, start a server, etc. And my clients may not have Open Office installed.
RTF is readable from Python, but I couldn't find any way/libraries to convert RTF documents to PDF.
At the moment I'm exporting from Microsoft Word to HTML, replacing the values and using PyQt to convert it to a PDF. However it loses formatting features and looks awful. I'm surprised there isn't a well known library which lets you edit a variety of document formats and convert them into other formats, am I missing something?
Update: Thanks for the advice, I'll have a look at using Latex.
Thanks,
Jackson

Have you looked into using LaTeX documents?
They are perfect to use programatically (compiling documents? You gotta love that...), and you have several Python frameworks you can use such as plasTeX and PyTex.
Exporting a LaTeX documents to PDF is almost immediate.

Since you're already using PyQt anyway, it might be worth looking at Qt's built-in RTF processing module which looks decent. Here's the documentation on detailed content manipulation including inserting tables. Also the QPrinter module's default print-to-file format happens to be PDF.
Without knowing more about your particular needs it's hard to say if these would do what you want, but since your application already has PyQt as a dependency, seems silly to introduce any more without evaluating the functionality you've already got available.
The non-GUI parts of the Qt framework are often overlooked though.
edit: included more links.

You might want to try ReportLab. The open source version can write PDFs, and the commercial version has a lot of really nice abstractions to allow output to a variety of different formats from a single input.

I don't know the kind of odience of your program, Tex is good and i would go with it.
Another possible choice is Excel format, parsing it with xlrd.
I've used it a couple of time and it's pretty straightforward.
Excel file is a good for the following reasons:
Well known format easy to edit
You could prepare a predefined template with constrains and table

Creating XML documents, transforming them to XSL/fo and rendering with Fop or RenderX. If you use docbook as the primary input, there are toolchains freely available for converting that to PDF, RTF, HTML and so forth.
It is rather quirky to use and not my idea of fun, but is does deliver and can be embedded in an application, AFAICT.
Creating docbook is very straightforward as it has a wide range of semantic tags, table support etc to give a "meaningful" markup which can be reliably formatted. The XSL stylesheets are modular and allow parts to be customized or replaced to generate your own look and feel.
It works well for relatively free flow documents with lots of text.
For filling in the blanks kind of documents, a regular reporting engine may be a better fit, or some straighforward XSL stylesheets spitting out the XSL-fo directly.