Head and tail in one line

Question

Is there a pythonic way to unpack a list in the first element and the \"tail\" in a single command?

For example:

>> head, tail = **some_magic a         


        

Answer 1

For O(1) complexity of head,tail operation you should use deque however.

Following way:

from collections import deque
l = deque([1,2,3,4,5,6,7,8,9])
head, tail = l.popleft(), l

It's useful when you must iterate through all elements of the list. For example in naive merging 2 partitions in merge sort.