setting default printer custom page size with python

Question

At the organization I work for, different printers are set up at various locations. All are mainly used to print A4-sized documents, so the defaults are set up accordingly.

We are also using a bunch of custom-sized forms which people have up to now been filling in by hand. Recently, I was tasked with setting up print-automation onto the said forms from our central database.

I'm using reportlab to create temporary pdf files which I am then trying to send to the default printer. All is relatively simple, save for getting the printers to register a custom paper size.

I got as far as the following code snippet, but I'm really stuck.

import tempfile
import win32api
import win32print

pdf_file = tempfile.mktemp(".pdf")

#CREATION OF PDF FILE WITH REPORTLAB

printer = win32print.GetDefaultPrinter()
PRINTER_DEFAULTS = {"DesiredAccess":win32print.PRINTER_ALL_ACCESS}
pHandle = win32print.OpenPrinter(printer, PRINTER_DEFAULTS)
level = 2
properties = win32print.GetPrinter(pHandle, level)
pDevModeObj = properties["pDevMode"]

pDevModeObj.PaperSize = 0
pDevModeObj.PaperLength = 2200 #SIZE IN 1/10 mm
pDevModeObj.PaperWidth = 1000 #SIZE IN 1/10 mm

properties["pDevMode"]=pDevModeObj
win32print.SetPrinter(pHandle,level,properties,0)
    
#OPTION ONE
#win32api.ShellExecute(0, "print", pdf_file, None, ".", 0)

#OPTION TWO
win32api.ShellExecute (0,"printto",pdf_file,'"%s"' % printer,".",0)

win32print.ClosePrinter(pHandle)

It just does not work. Printers do not report a "paper size mismatch", like they should when a non-A4 document is being sent to them. And when I try printing to a PDF printer, it also defaults to A4.

When calling

print(pDevModeObj.PaperSize)
print(pDevModeObj.PaperLength)
print(pDevModeObj.PaperWidth)

everything seems to be in order, so I'm guessing I don't know how to send those paper size values back to the printer settings.

I'd greatly appreciate any insights, suggestions, ... Thank you all.

I apologize in advance if I am posting a question that has already been answered. If it has been, I really must have been handed an extra chunk of bad luck and missed the answer. So before anyone decides to downvote, here is a list of all the resources I checked out (examples not all in python, and a few are not using the win32api), and couldn't get the thing to work properly:

Using the shell to print is pretty flaky. If you spoke to the printer directly you'd be able to control the paper. I suspect your real problem is actually having chosen the wrong way to print. — David Heffernan

Strive Sun Strive Sun · Accepted Answer · 2020-11-17T03:57:21

ShellExecute is using the default printing parameters. If you need to use the reset DevMode for printing, you can use CreateDC.

Refer: GDI Print API

If you use SetPrinter to modify the default DEVMODE structure for a printer (globally setting the printer defaults), you must first call the DocumentProperties function to validate the DEVMODE structure.

Refer:

You can also directly use DocumentProperties to modify printer initialization information.

Then pass pDevModeObj to CreateDC, and use StartDoc and StartPage to print.

Similar case: Change printer tray with pywin32

setting default printer custom page size with python

1 Answers