New submission from Leo:
Each call of namedtuple will create a new class object even if an equal class,
i.e. for the same fields has been created before.
Applying the singleton pattern would be more efficient at least in two
respects:
* it would reduce the number of class objects.
* checking for field names can be done by calling isinstance.
I therefore propose a new boolean keyword argument 'singleton' for the
namedtuple function. It should
default to True. If a pre-existing rather than new class object is returned,
the provided class name is
disregarded. In many cases, the caller will use a local binding anyway.
The singleton pattern could be implemented along the following schema:
cache = {}
if not fields in cache:
cache[fields] = new_namedtuple
return cache[fields]
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components: Library (Lib)
messages: 228640
nosy: fhaxbo...@googlemail.com
priority: normal
severity: normal
status: open
title: Singleton pattern for namedtuple
type: enhancement
versions: Python 3.4
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Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue22562>
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