Up to this level of Python, you have learned data structure of Python.
module of Python includes implementations of several data structures
that extend those found in other modules. Gradually you will learn the power of collections module.
Let us discuss its power one by one.
Python Collections Deque
In simple words, A double-ended queue, or deque, allows adding and removing elements from either end.
Let us discuss Deque
Operation one by one. Deque
supports some list operations.
give the length of deque. You can see the right and left end of Deque from above figure.
Python deque Populating
Let us discuss more operation of Deque
. As it is Double ended queue means you can add element from either side.
The Out-put clearly shows the code effect. The extendleft()
function iterates over its input and performs the equivalent
of an appendleft()
for each item. The end result is that the deque
contains the input
sequence in reverse order.
Python deque Consuming
can be consume from both ends or either end.
Lets discuss our next example.
to remove an item from the right end of the deque
remove from the left end.
Python deque Rotating
Python Deque allows you to rotate items in either side. Right rotation is taken as positive rotation.
for right rotation up to n
number. For left rotation use rotate(-n)
From out-put you can deduce that in right rotation, items are shifted to right direction. In left rotation, items are
shifted to left direction.