How do I read text from the clipboard?

You can use the module called win32clipboard, which is part of pywin32.

Here is an example that first sets the clipboard data then gets it:

import win32clipboard

# set clipboard data
win32clipboard.OpenClipboard()
win32clipboard.EmptyClipboard()
win32clipboard.SetClipboardText('testing 123')
win32clipboard.CloseClipboard()

# get clipboard data
win32clipboard.OpenClipboard()
data = win32clipboard.GetClipboardData()
win32clipboard.CloseClipboard()
print data

An important reminder from the documentation:

When the window has finished examining or changing the clipboard,
close the clipboard by calling CloseClipboard. This enables other
windows to access the clipboard. Do not place an object on the
clipboard after calling CloseClipboard.