Define seek() in file handling.
And also Define its mode(0,1,2).
seek() is all about the placement of the cursor in a file.
Also its mode?
from https://www.tutorialspoint.com/JUMP_LINK__&&__python__&&__JUMP_LINK/file_seek.htm "This is optional and defaults to 0 which means absolute file positioning, other values are 1 which means seek relative to the current position and 2 means seek relative to the file's end."