4004ebd1cb
git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@2513 fd906abe-77d9-0310-91a1-e0d9ade77398
74 lines
2.5 KiB
Text
74 lines
2.5 KiB
Text
========================================
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Indexed Collections for Various Purposes
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========================================
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$Id$
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Multikey Dictionaries
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=====================
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A MultiKeyDict is a dictionary that expects its keys to be tuples.
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>>> from cybertools.util.multikey import MultiKeyDict
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>>> registry = MultiKeyDict()
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>>> registry[('index.html', None, None, None)] = 'global index.html'
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>>> registry[('index.html', None, None, None)]
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'global index.html'
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So this would be nothing special - any dictionary is able to provide this
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functionality; but a MultiKeyDict has some fallback mechanisms for retrieving
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objects only partly fitting the requested key:
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>>> registry[('index.html', 'topic', 'zope3', 'Custom')]
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'global index.html'
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>>> registry[('index.html', 'topic', None, None)] = 'index.html for type "topic"'
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>>> registry[('index.html', 'topic', 'zope3', 'Custom')]
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'index.html for type "topic"'
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It is also possible to keep intermediate parts of a key variable by
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setting them to None:
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>>> registry[('index.html', None, None, 'Custom')] = 'Global index.html for Custom skin'
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The more on the left a matching key part is the higher is its priority:
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>>> registry[('index.html', 'topic', 'zope3', 'Custom')]
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'index.html for type "topic"'
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>>> registry[('index.html', 'task', 'bugfixes', 'Custom')]
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'Global index.html for Custom skin'
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Index entries that are present in the stored dictionary must always match:
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>>> registry[('edit.html', 'topic', 'zope3', 'Custom')] = 'very special edit.html'
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>>> registry[('index.html', 'task', 'bugfixes', 'Custom')]
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'Global index.html for Custom skin'
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>>> registry[('index.html', 'topic', 'zope3', 'Custom')]
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'index.html for type "topic"'
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>>> registry.get(('edit.html', 'task', 'bugfixes', 'Custom')) is None
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True
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>>> registry[('edit.html', None, None, 'Custom')] = 'edit.html for Custom skin'
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>>> registry.get(('edit.html', 'task', 'bugfixes', '')) is None
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True
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>>> registry[('edit.html', 'task', 'bugfixes', 'Custom')]
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'edit.html for Custom skin'
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If you don't know any more what entries we had added to the registry just
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query its items() method:
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>>> registry.items()
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((('edit.html', 'topic', 'zope3', 'Custom'), 'very special edit.html'),
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(('edit.html', None, None, 'Custom'), 'edit.html for Custom skin'),
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(('index.html', None, None, None), 'global index.html'),
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(('index.html', None, None, 'Custom'), 'Global index.html for Custom skin'),
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(('index.html', 'topic', None, None), 'index.html for type "topic"'))
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