python 2.1 singleton

[Alexiev Nikolay]

I need a simple implementation of singleton that will work on python 2.1. I
havn't got idea how to creat without staticmethod. Can you give me a
solution ??? 10x in advance

 

[Duncan Booth]

I need a simple implementation of singleton that will work on python
2.1. I havn't got idea how to creat without staticmethod. Can you give
me a solution ??? 10x in advance

The simplest singleton implementation, which works for any version of
Python is simply to use a module as your singleton instead of a class. You
can get hold of the singleton object from anywhere simply by importing it.
All functions defined in a module are effectively static methods on the
module object.

 

[Alex Martelli]

The simplest singleton implementation, which works for any version of
Python is simply to use a module as your singleton instead of a class. You
can get hold of the singleton object from anywhere simply by importing it.
All functions defined in a module are effectively static methods on the
module object.

Amen, Hallelujah. This will be optimal any time you don't need some of the
capabilities that classes have over modules -- basically, inheritance and
special methods. When you DO need to expose a class, I still suggest the
Borg nonpattern, http://www.aleax.it/5ep.html -- even though Guido hates
it with a vengeance, I'm still convinced it's superior to Singleton.

If you _do_ perversely want the Singleton DP no matter what, you don't
need static methods -- you can use a toplevel function just as well.

If you _do_ perversely want static methods in 2.1 no matter what,

class staticmethod:
def __init__(self, thefunc): self.f = thefunc
def __call__(self, *a, **k): return self.f(*a, **k)

and just use this staticmethod instead of 2.2's builtin one.


Alex