Download our e-book of Introduction To Python
Related Blog
Matplotlib - Subplot2grid() FunctionDiscuss Microsoft Cognitive ToolkitMatplotlib - Working with ImagesMatplotlib - PyLab moduleMatplotlib - Working With TextMatplotlib - Setting Ticks and Tick LabelsCNTK - Creating First Neural NetworkMatplotlib - MultiplotsMatplotlib - Quiver PlotPython - Chunks and Chinks View More
Top Discussion
How can I write Python code to change a date string from "mm/dd/yy hh: mm" format to "YYYY-MM-DD HH: mm" format? Which sorting technique is used by sort() and sorted() functions of python? How to use Enum in python? Can you please help me with this error? I was just selecting some random columns from the diabetes dataset of sklearn. Decision tree is a classification algo...How can it be applied to load diabetes dataset which has DV continuous Objects in Python are mutable or immutable? How can unclassified data in a dataset be effectively managed when utilizing a decision tree-based classification model in Python? How to leave/exit/deactivate a Python virtualenvironment Join Discussion
Top Courses
Webinars
Python - Deque
Sanjeev Shah
3 years ago
In this article, we will try to learn about deque with some examples.
Table Of Content
- Python - Deque
- What is Deque?
- Deque Methods
- Deque - extend() Method
- Deque - extendleft()
- Method to Add Numbers To Left End
- Deque - rotate() Method To Rotate The Deque
- Deque - reverse() Method To Reverse The Deque
- Conclusion
What is Deque?
Deque is a double-ended queue. It has two ends, a front and a rear end. In Python, we can implement deque using a collection module. Deque provides a fast update, insert and delete operations than a list data structure. For appending and pop operation, deque provides time complexity O(1).
# importing "collections" module or deque operations
import collections
dq = collections.deque(["Mon","Tue","Wed"])
dq.append("Thu")
print ("Appended at right - ")
print (dq)
dq.appendleft("Sun")
print ("Appended at right at left is - ")
print (dq)
dq.pop()
print ("Deleting from right - ")
print (dq)
DoubleEnded.popleft()
print ("Deleting from left - ")
print (dq)
Output:
Appended at right -
deque(['Mon', 'Tue', 'Wed', 'Thu'])
Appended at right at left is -
deque(['Sun', 'Mon', 'Tue', 'Wed', 'Thu'])
Deleting from right -
deque(['Sun', 'Mon', 'Tue', 'Wed'])
Deleting from left -
deque(['Mon', 'Tue', 'Wed']) Recommended blog for you : Introduction to Data Structures
Deque methods
- extend()
- extendleft()
- rotate()
- reverse()
Deque - extend() Method
# importing "collections" module for deque operations
import collections
# initializing deque
dq = collections.deque([10, 20, 30,])
# add numbers to right end using extend() method
# adds 40,50,60 to right end
dq.extend([40,50,60])
# extended Deque
print ("extended deque at the end is: ")
print (dq)Output:
The deque after extending deque at end is :
deque([10, 20, 30, 40, 50, 60])Deque - extendleft()
Method to Add Numbers To Left End
# add numbers to left end using extendleft() method
# adds 70,80,90 to right end
dq.extendleft([70,80,90])
# Ater extendleft deque operation
print ("extended deque is : ")
print (dq) Output:
The deque after extending deque at beginning is :
deque([90, 80, 70, 10, 20, 30, 40, 50, 60])Deque - rotate()
Method To Rotate The Deque
# to rotate the deque use rotate() method
# rotates by 3 to left
dq.rotate(-3)
# printing rorated deque
print ("rotated deque is : ")
print (dq) Output:
The deque after rotating deque is :
deque([10, 20, 30, 40, 50, 60, 90, 80, 70])Deque - reverse()
Method To Reverse The Deque
# to reverse the deque using reverse() method
dq.reverse()
# printing reverse deque
print (" reverse deque is: ")
print (dq)Output:
The deque after reversing deque is :
deque([70, 80, 90, 60, 50, 40, 30, 20, 10])Conclusion
I hope you enjoyed reading this article and finally, you came
to know about Python - Deque and its operations.
To know more about python programming language follow the insideaiml youtube channel.
For more such blogs/courses on data science, machine
learning, artificial intelligence and emerging new technologies do visit us at InsideAIML.
Thanks for reading…
Happy Learning…
Recommended Course for you