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Indexed Collections for Various Purposes
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$Id$
Multikey Dictionaries
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A MultiKeyDict is a dictionary that expects its keys to be tuples.
>>> from cybertools.index.multikey import MultiKeyDict
>>> registry = MultiKeyDict()
>>> registry[('index.html', None, None, None)] = 'global index.html'
>>> registry[('index.html', None, None, None)]
'global index.html'
So this would be nothing special - any dictionary is able to provide this
functionality; but a MultiKeyDict has some fallback mechanisms for retrieving
objects only partly fitting the requested key:
>>> registry[('index.html', 'topic', 'zope3', 'Custom')]
'global index.html'
>>> registry[('index.html', 'topic', None, None)] = 'index.html for type "topic"'
>>> registry[('index.html', 'topic', 'zope3', 'Custom')]
'index.html for type "topic"'
It is also possible to keep intermediate parts of a key variable by
setting them to None:
>>> registry[('index.html', None, None, 'Custom')] = 'Global index.html for Custom skin'
The more on the left a matching key part is the higher is its priority:
>>> registry[('index.html', 'topic', 'zope3', 'Custom')]
'index.html for type "topic"'
>>> registry[('index.html', 'task', 'bugfixes', 'Custom')]
'Global index.html for Custom skin'
Index entries that are present in the stored dictionaries must always match:
>>> registry[('edit.html', 'topic', 'zope3', 'Custom')] = 'very special edit.html'
>>> registry[('index.html', 'task', 'bugfixes', 'Custom')]
'Global index.html for Custom skin'
>>> registry[('index.html', 'topic', 'zope3', 'Custom')]
'index.html for type "topic"'
>>> registry.get(('edit.html', 'task', 'bugfixes', 'Custom')) is None
True
>>> registry[('edit.html', None, None, 'Custom')] = 'edit.html for Custom skin'
>>> registry.get(('edit.html', 'task', 'bugfixes', '')) is None
True
>>> registry[('edit.html', 'task', 'bugfixes', 'Custom')]
'edit.html for Custom skin'
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