Why does everyone want to do everything with Python? Shell scripts, awk, etc. are more than sufficient for this task.
#!/bin/sh if test -f "$1".resume then resumepoint=`cat "$1".resume` else resumepoint=0 fi mplayer -ss $resumepoint "$1"|awk 'BEGIN{RS="\r"}{if ($1=="A:") t=$2}END{print t}' > "$1".resume
$ abplayer /route/to/audiobook.mp3
What format are your audiobooks? mpg123 might seem a more natural choice than mplayer, if they're mp3; otherwise mplayer might be better.