'Provides "Strip trailing whitespace" under the "Format" menu.'

class RstripExtension:

menudefs = [
('format', [None, ('Strip trailing whitespace', '<<do-rstrip>>'), ] ), ]

def __init__(self, editwin):
self.editwin = editwin
self.editwin.text.bind("<<do-rstrip>>", self.do_rstrip)

def do_rstrip(self, event=None):

text = self.editwin.text
undo = self.editwin.undo

undo.undo_block_start()

end_line = int(float(text.index('end')))
for cur in range(1, end_line):
txt = text.get('%i.0' % cur, '%i.end' % cur)
raw = len(txt)
cut = len(txt.rstrip())
# Since text.delete() marks file as changed, even if not,
# only call it when needed to actually delete something.
if cut < raw:
text.delete('%i.%i' % (cur, cut), '%i.end' % cur)

undo.undo_block_stop()

if __name__ == "__main__":
import unittest
unittest.main('idlelib.idle_test.test_rstrip', verbosity=2, exit=False)