Have you tried Send Intent?
from androidhelper import Android
droid = Android()
droid.startActivity(None, None, None, None, None, 'com.sec.android.app.launcher', 'com.android.launcher2.Launcher')
# startActivity(action, uri, type, extras, wait, packagename, classname)
for the uri: file:///<file path/document.pdf>
You'll still need an App that connects to your printer and need the packagename & classname
for that printer App (still not guaranteed to work) It depends on how the App was written.
I've had pretty good luck interacting with other Android apps using python send intent scripts,
but it's not always allowed.