World's Best AI Learning Platform with profoundly Demanding Certification Programs
Designed by IITian's, only for AI Learners.
Download our e-book of Introduction To Python
Related Blog
Top Discussion
How to leave/exit/deactivate a Python virtualenvironment Exception Type: JSONDecodeError at /update/ Exception Value: Expecting value: line 1 column 1 (char 0) How to split numpy array with mask? How can i change terminal path in vscode? Create a dataframe with number of column and and column names according to the user How to Delete Python Object? Automatically run %matplotlib inline in IPython Notebook Explain Scopes in Python? Join Discussion
Top Courses
Master's In Artificial Intelligence Job Guarantee Program
4.5 (1,292 Ratings)
547 Learners
Webinars
Live Webinar on: Jobs In Data Science in 2022 and onwards.
Oct 13th (7:00 PM) 431 Registered
Python Design Patterns - Singleton
Neha Kumawat
10 months ago
This pattern restricts the instantiation of a class to one object. It is a type of creational pattern and involves only one class to create methods and specified objects.
It provides a global point of access to the instance created.
How to implement a singleton class?
The following program demonstrates the implementation of singleton class where it prints the instances created multiple times.
class Singleton:
__instance = None
@staticmethod
def getInstance():
""" Static access method. """
if Singleton.__instance == None:
Singleton()
return Singleton.__instance
def __init__(self):
""" Virtually private constructor. """
if Singleton.__instance != None:
raise Exception("This class is a singleton!")
else:
Singleton.__instance = self
s = Singleton()
print s
s = Singleton.getInstance()
print s
s = Singleton.getInstance()
print s
Output
The above program generates the following output −
The number of instances created are same and there is no difference in the objects listed in output.
Like the Blog, then Share it with your friends and colleagues to make this AI community stronger.
To learn more about nuances of Artificial Intelligence, Python Programming, Deep Learning, Data Science and Machine Learning, visit our insideAIML blog page.
Keep Learning. Keep Growing.