Found this little bug today in some old (untested code). I was amused that the code would have worked using pre-increment operator (and yet, still been wrong).

# Simplified example, in the original code this was 3 lines long
# Assume use_record_map = false;
record_id = (use_record_map) ? lookup_record_id(foo) : record_id++;

Pythons lack of ++ / — operators makes a little more sense now (one extra character in exchange for removing several type of bugs. Even if they are rather obvious bugs).