My wild guess: Not a common use case. Double-ended queue is a special purpose structure.
As Kent said, the suggestion of making index 0 insertions and deletions on lists more efficent was made, and the decision was to leave list alone and provide collections.deque instead. This let deque sacrifice some of list's flexibility in favour of increased speed.
Appropriate parts of the core which needed a FIFO were then updated to use the new data type, while everything else continues to use lists.
Cheers, Nick.
--
Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia
---------------------------------------------------------------
http://boredomandlaziness.skystorm.net
--
http://mail.python.org/mailman/listinfo/python-list
