ericflo

import time

from contextlib import contextmanager

@contextmanager
def easyprofile(msg):
    before = time.time()
    yield
    print '%s took %0.2fsec' % (msg, time.time() - before)

defunkt

Vim

autocmd BufWritePre * :%s/\s\+$//e

Emacs

(add-hook 'before-save-hook 'delete-trailing-whitespace)

Textmate