copy asset file from .rpa to temp directory (help!)

[cimokudo]

hi there, im newbie here
i stuck on how to copy my asset file (actually a .png image file) to windows temp directory (%temp%)

step i done :
1. im using copy, copy2, copyfile and other copy method from shutil
2. read the file using renpy.file().read() then write using open().write()

those method keep return 0kb file which is a blank file,
anyone can help?

thanks