Print PDF file in duplex mode via Python

Question

I have an script in Python that prints PDF files.
The script works using win32api.ShellExecute() and everything is fine, but now, I need to print PDF files that have double sided content, user manuals in concrete.
I have tried setting the duplex mode in win32print, but nothing works, the printer still print 2 pages on 2 sheets for my PDF instead of two pages on a double sided sheet. The printer works with this mode in other applications, but with the python script doesn't work well. This is part of the code I used to print:

name = win32print.GetDefaultPrinter()
printdefaults = {"DesiredAccess": win32print.PRINTER_ALL_ACCESS}
handle = win32print.OpenPrinter(name, printdefaults)
level = 2
attributes = win32print.GetPrinter(handle, level)
attributes['pDevMode'].Duplex
attributes['pDevMode'].Duplex = 1
win32print.SetPrinter(handle, level, attributes, 0)
win32print.GetPrinter(handle, level)['pDevMode'].Duplex
win32api.ShellExecute(0,'print','file.pdf','.','/route',0)

Any idea why this doesn't works? Thanks.

Answer 1

Try to run this code:

import win32api
import win32print

name = win32print.GetDefaultPrinter()

#printdefaults = {"DesiredAccess": win32print.PRINTER_ACCESS_ADMINISTER}
printdefaults = {"DesiredAccess": win32print.PRINTER_ACCESS_USE}
handle = win32print.OpenPrinter(name, printdefaults)

level = 2
attributes = win32print.GetPrinter(handle, level)

print "Old Duplex = %d" % attributes['pDevMode'].Duplex

#attributes['pDevMode'].Duplex = 1    # no flip
#attributes['pDevMode'].Duplex = 2    # flip up
attributes['pDevMode'].Duplex = 3    # flip over

## 'SetPrinter' fails because of 'Access is denied.'
## But the attribute 'Duplex' is set correctly
try:
    win32print.SetPrinter(handle, level, attributes, 0)
except:
    print "win32print.SetPrinter: set 'Duplex'"

res = win32api.ShellExecute(0, 'print', 'test.pdf', None, '.', 0)

win32print.ClosePrinter(handle)

It works on my computer: Windows 10, Python 2.7.14, pypiwin32-220

Notes:

1. On my computer PRINTER_ACCESS_ADMINISTER causes 'Access is denied' in OpenPrinter.
2. On my computer SetPrinter fails with 'Access is denied'. But 'Duplex' is set correctly..