This is the community forum for my apps Pythonista and Editorial.
For individual support questions, you can also send an email. If you have a very short question or just want to say hello — I'm @olemoritz on Twitter.
my_text_field.secure = True should do the trick (no idea why this is missing from the docs). If you're using the UI editor, you can enable the "Password Field" switch instead.
my_text_field.secure = True