Arnaud Delobelle wrote:
mk <mrk...@gmail.com> writes:
[...]
hashable
..
    All of Python’s immutable built-in objects are hashable, while no
mutable containers (such as lists or dictionaries) are.

Well ok, hashable they're not; but apparently at least dict and list
have id()?

lists and dicts are not hashable, but their types are:

Oh.

hash(dict)
4296155808
hash(list)
4296151808

So just use the type as the key to the dictionary you maintain in your
singleton.

Hmm I have tested it and it seems to work.

But the question is what you use your singleton for.

Well, partly this was for sake of learning; but partially I was thinking whether singleton as such may be useful for implementing "global queue of tasks" for worker threads in a large program: instead of handing down over and over the same reference to the global queue of tasks, classes or functions could call Singleton() and be done with it.

Or I could make my life simpler and use global variable. :-)

I will soon need to write such program, with remote calls from pyro (most probably), many worker threads, short-running jobs and long-running jobs, etc.


Regards,
mk

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