Function copy_file

Copy a file 'src' to 'dst'. If 'dst' is a directory, then 'src' is copied there with the same name; otherwise, it must be a filename. (If the file exists, it will be ruthlessly clobbered.) If 'preserve_mode' is true (the default), the file's mode (type and permission bits, or what

(src, dst, preserve_mode=1, preserve_times=1, update=0,
              link=None, verbose=1, dry_run=0)