Hi. Since Python 3.2, compileall functions supports the optimization level through the `optimize` parameter. I guess you are using Python2.7 or so? Also, there's a note in compileall's documentation regarding the command line switch for the optimization level:

"
There is no command-line option to control the optimization level used by the compile() function, because the Python interpreter itself already provides the option: python -O -m compileall.
"
http://docs.python.org/3.2/library/compileall.html#command-line-use