Undoing character read from file

[MRAB]

On 16/02/2012 23:10, Emeka wrote:
> Hello All,
>
> I know about seek and tell while using readline. What about if I am
> using read, and I want to undo the last character I just read(to return
> it back to the stream). How do I achieve this?
>
Try:

     f.seek(-1, 1)

It seeks -1 relative to the current position (the second argument
defaults to 0 for relative to start of file).