In python, How to use singleton pattern?

Question

My code is :

  class Handler():

        # make it static
        from pymongo import MongoClient
        client = MongoClient("localhost", 27017)
        db = client.newsdb
        news = db.news

I want to make the client variable to be static, so is above code the correct way to do that ? I also want to use singleton pattern, because maybe the MongoClient is very large element, and I want to new() this element when I really need it....

How can I do that in python ? As a beginner, maybe ask some stupid question, sorry for that in advance...

score 4 · Accepted Answer · answered Jan 17 '15 at 13:35

Simplest way to use singleton pattern in Python it's move all code to separate module and import it:

singleton.py:

    from pymongo import MongoClient
    client = MongoClient("localhost", 27017)
    db = client.newsdb
    news = db.news

and use it in other modules:

import singleton
print(singleton.news)

In python, How to use singleton pattern?

1 Answers1