zope.container
API
Interfaces
Container-related interfaces
- exception zope.container.interfaces.ContainerError[source]
Bases:
Exception
An error of a container with one of its components.
- interface zope.container.interfaces.IBTreeContainer[source]
Extends:
zope.container.interfaces.IContainer
Container that supports BTree semantics for some methods.
- items(key=None)
Return an iterator over the key-value pairs in the container.
If
None
is passed askey
, this method behaves as if no argument were passed; exactly as required forIContainer.items()
.If
key
is in the container, the first item provided by the iterator will correspond to that key. Otherwise, the first item will be for the key that would come next ifkey
were in the container.
- keys(key=None)
Return an iterator over the keys in the container.
If
None
is passed askey
, this method behaves as if no argument were passed; exactly as required forIContainer.keys()
.If
key
is in the container, the first key provided by the iterator will be that key. Otherwise, the first key will be the one that would come next ifkey
were in the container.
- values(key=None)
Return an iterator over the values in the container.
If
None
is passed askey
, this method behaves as if no argument were passed; exactly as required forIContainer.values()
.If
key
is in the container, the first value provided by the iterator will correspond to that key. Otherwise, the first value will be for the key that would come next ifkey
were in the container.
- interface zope.container.interfaces.IContainer[source]
Extends:
zope.container.interfaces.IReadContainer
,zope.container.interfaces.IWriteContainer
Readable and writable content container.
- interface zope.container.interfaces.IContainerModifiedEvent[source]
Extends:
zope.lifecycleevent.interfaces.IObjectModifiedEvent
The container has been modified.
This event is specific to “containerness” modifications, which means addition, removal or reordering of sub-objects.
- interface zope.container.interfaces.IContainerNamesContainer[source]
Extends:
zope.container.interfaces.IContainer
Containers that always choose names for their items.
- interface zope.container.interfaces.IContentContainer[source]
Extends:
zope.container.interfaces.IContainer
A container that is to be used as a content type.
- interface zope.container.interfaces.IFind[source]
Find support for containers.
- find(id_filters=None, object_filters=None)
Find object that matches all filters in all sub-objects.
This container itself is not included.
- interface zope.container.interfaces.IItemContainer[source]
Extends:
zope.interface.common.mapping.IItemMapping
Minimal readable container.
- interface zope.container.interfaces.IItemWriteContainer[source]
Extends:
zope.container.interfaces.IWriteContainer
,zope.container.interfaces.IItemContainer
A write container that also supports minimal reads.
- interface zope.container.interfaces.IOrdered[source]
Objects whose contents are maintained in order.
- updateOrder(order)
Revise the order of keys, replacing the current ordering.
order is a list or a tuple containing the set of existing keys in the new order.
order
must containlen(keys())
items and cannot contain duplicate keys.Raises
TypeError
if order is not a tuple or a list.Raises
ValueError
if order contains an invalid set of keys.
- interface zope.container.interfaces.IOrderedContainer[source]
Extends:
zope.container.interfaces.IOrdered
,zope.container.interfaces.IContainer
Containers whose contents are maintained in order.
- interface zope.container.interfaces.IReadContainer[source]
Extends:
zope.container.interfaces.ISimpleReadContainer
,zope.interface.common.mapping.IEnumerableMapping
Readable containers that can be enumerated.
- interface zope.container.interfaces.IReservedNames[source]
A sequence of names that are reserved for that container
- interface zope.container.interfaces.ISimpleReadContainer[source]
Extends:
zope.container.interfaces.IItemContainer
,zope.interface.common.mapping.IReadMapping
Readable content containers.
- interface zope.container.interfaces.IWriteContainer[source]
An interface for the write aspects of a container.
- __setitem__(name, object)
Add the given
object
to the container under the given name.Raises a
TypeError
if the key is not a unicode or ascii string.Raises a
ValueError
if the key is empty, or if the key contains a character which is not allowed in an object name.Raises a
KeyError
if the key violates a uniqueness constraint.The container might choose to add a different object than the one passed to this method.
If the object doesn’t implement
IContained
, then one of two things must be done:If the object implements
ILocation
, then theIContained
interface must be declared for the object.Otherwise, a
ContainedProxy
is created for the object and stored.
The object’s
__parent__
and__name__
attributes are set to the container and the given name.If the old parent was
None
, then anIObjectAddedEvent
is generated, otherwise, anIObjectMovedEvent
is generated. AnIContainerModifiedEvent
is generated for the container.If the object replaces another object, then the old object is deleted before the new object is added, unless the container vetos the replacement by raising an exception.
If the object’s
__parent__
and__name__
were already set to the container and the name, then no events are generated and no hooks. This allows advanced clients to take over event generation.
- __delitem__(name)
Delete the named object from the container.
Raises a
KeyError
if the object is not found.If the deleted object’s
__parent__
and__name__
match the container and given name, then anIObjectRemovedEvent
is generated and the attributes are set toNone
. If the object can be adapted toIObjectMovedEvent
, then the adapter’smoveNotify
method is called with the event.Unless the object’s
__parent__
and__name__
attributes were initiallyNone
, generate anIContainerModifiedEvent
for the container.If the object’s
__parent__
and__name__
were already set toNone
, then no events are generated. This allows advanced clients to take over event generation.
- exception zope.container.interfaces.InvalidContainerType[source]
-
The type of a container is not valid.
- exception zope.container.interfaces.NameReserved[source]
Bases:
ValueError
The name is reserved for this container
- exception zope.container.interfaces.UnaddableError(container, obj, message='')[source]
Bases:
ContainerError
An object cannot be added to a container.
Implementations
Bases and Events
Classes to support implementing IContained
- class zope.container.contained.Contained[source]
Bases:
object
Simple mix-in that defines
__parent__
and__name__
attributes and implementsIContained
.
- class zope.container.contained.ContainedProxy[source]
Bases:
ContainedProxyBase
Wraps an object to implement
zope.container.interfaces.IContained
with a new__name__
and__parent__
.The new object provides everything the wrapped object did, plus
IContained
andIPersistent
.
- class zope.container.contained.ContainedProxyClassProvides(cls, metacls, *interfaces)[source]
Bases:
ClassProvides
Delegates __provides__ to the instance.
>>> class D1(ContainedProxy): ... pass >>> class Base(object): ... pass >>> base = Base() >>> d = D1(base) >>> d.__provides__ = 42 >>> base.__provides__ 42 >>> del d.__provides__ >>> hasattr(base, '__provides__') False
- class zope.container.contained.ContainerModifiedEvent(object, *descriptions)[source]
Bases:
ObjectModifiedEvent
The container has been modified.
Init with a list of modification descriptions.
- class zope.container.contained.ContainerSublocations(container)[source]
Bases:
object
Get the sublocations for a container
Obviously, this is the container values:
>>> class MyContainer(object): ... def __init__(self, **data): ... self.data = data ... def __iter__(self): ... return iter(self.data) ... def __getitem__(self, key): ... return self.data[key]
>>> container = MyContainer(x=1, y=2, z=42) >>> adapter = ContainerSublocations(container) >>> sublocations = list(adapter.sublocations()) >>> sublocations.sort() >>> sublocations [1, 2, 42]
- class zope.container.contained.DecoratedSecurityCheckerDescriptor[source]
Bases:
object
Descriptor for a Decorator that provides a decorated security checker.
>>> class WithChecker(object): ... __Security_checker__ = object()
>>> class D1(ContainedProxy): ... pass
>>> d = D1(object()) >>> d.__Security_checker__ <...Checker...>
An existing checker is added to this one:
>>> d = D1(WithChecker()) >>> d.__Security_checker__ <...CombinedChecker...>
- class zope.container.contained.DecoratorSpecificationDescriptor[source]
Bases:
ObjectSpecificationDescriptor
Support for interface declarations on decorators
>>> from zope.interface import Interface, directlyProvides, implementer >>> class I1(Interface): ... pass >>> class I2(Interface): ... pass >>> class I3(Interface): ... pass >>> class I4(Interface): ... pass
>>> @implementer(I1) ... class D1(ContainedProxy): ... pass
>>> @implementer(I2) ... class D2(ContainedProxy): ... pass
>>> @implementer(I3) ... class X: ... pass
>>> x = X() >>> directlyProvides(x, I4)
Interfaces of X are ordered with the directly-provided interfaces first
>>> [interface.getName() for interface in list(providedBy(x))] ['I4', 'I3']
When we decorate objects, what order should the interfaces come in? One could argue that decorators are less specific, so they should come last. This is subject to respecting the C3 resolution order, of course.
>>> [interface.getName() for interface in list(providedBy(D1(x)))] ['I4', 'I3', 'I1', 'IContained', 'IPersistent']
>>> [interface.getName() for interface in list(providedBy(D2(D1(x))))] ['I4', 'I3', 'I1', 'I2', 'IContained', 'IPersistent']
- zope.container.contained.contained(object, container, name=None)[source]
Establish the containment of the object in the container
Just return the contained object without an event. This is a convenience “macro” for:
containedEvent(object, container, name)[0]
This function is only used for tests.
- zope.container.contained.containedEvent(object, container, name=None)[source]
Establish the containment of the object in the container
The object and necessary event are returned. The object may be a
ContainedProxy
around the original object. The event is an added event, a moved event, or None.If the object implements
IContained
, simply set its__parent__
and__name__
attributes:>>> container = {} >>> item = Contained() >>> x, event = containedEvent(item, container, 'foo') >>> x is item True >>> item.__parent__ is container True >>> item.__name__ 'foo'
We have an added event:
>>> event.__class__.__name__ 'ObjectAddedEvent' >>> event.object is item True >>> event.newParent is container True >>> event.newName 'foo' >>> event.oldParent >>> event.oldName
Now if we call contained again:
>>> x2, event = containedEvent(item, container, 'foo') >>> x2 is item True >>> item.__parent__ is container True >>> item.__name__ 'foo'
We don’t get a new added event:
>>> event
If the object already had a parent but the parent or name was different, we get a moved event:
>>> x, event = containedEvent(item, container, 'foo2') >>> event.__class__.__name__ 'ObjectMovedEvent' >>> event.object is item True >>> event.newParent is container True >>> event.newName 'foo2' >>> event.oldParent is container True >>> event.oldName 'foo'
If the object implements
ILocation
, but notIContained
, set its__parent__
and__name__
attributes and declare that it implementsIContained
:>>> from zope.location import Location >>> from zope.location.interfaces import IContained >>> item = Location() >>> IContained.providedBy(item) False >>> x, event = containedEvent(item, container, 'foo') >>> x is item True >>> item.__parent__ is container True >>> item.__name__ 'foo' >>> IContained.providedBy(item) True
If the object doesn’t even implement
ILocation
, put aContainedProxy
around it:>>> item = [] >>> x, event = containedEvent(item, container, 'foo') >>> x is item False >>> x.__parent__ is container True >>> x.__name__ 'foo'
Make sure we don’t lose existing directly provided interfaces.
>>> from zope.interface import Interface, directlyProvides >>> class IOther(Interface): ... pass >>> from zope.location import Location >>> item = Location() >>> directlyProvides(item, IOther) >>> IOther.providedBy(item) True >>> x, event = containedEvent(item, container, 'foo') >>> IOther.providedBy(item) True
- zope.container.contained.dispatchToSublocations(object, event)[source]
Dispatch an event to sublocations of a given object
When a move event happens for an object, it’s important to notify subobjects as well.
We do this based on locations.
Suppose, for example, that we define some location objects.
>>> @zope.interface.implementer(ILocation) ... class L(object): ... def __init__(self, name): ... self.__name__ = name ... self.__parent__ = None ... def __repr__(self): ... return '%s(%s)' % ( ... self.__class__.__name__, str(self.__name__))
>>> @zope.interface.implementer(ISublocations) ... class C(L): ... def __init__(self, name, *subs): ... L.__init__(self, name) ... self.subs = subs ... for sub in subs: ... sub.__parent__ = self ... def sublocations(self): ... return self.subs
>>> c = C(1, ... C(11, ... L(111), ... L(112), ... ), ... C(12, ... L(121), ... L(122), ... L(123), ... L(124), ... ), ... L(13), ... )
Now, if we call the dispatcher, it should call event handlers for all of the objects.
Lets create an event handler that records the objects it sees:
>>> seen = [] >>> def handler(ob, event): ... seen.append((ob, event.object))
Note that we record the the object the handler is called on as well as the event object:
Now we’ll register it:
>>> from zope import component >>> from zope.lifecycleevent.interfaces import IObjectMovedEvent >>> component.provideHandler(handler, [None, IObjectMovedEvent])
We also register our dispatcher:
>>> component.provideHandler(dispatchToSublocations, ... [None, IObjectMovedEvent])
We can then call the dispatcher for the root object:
>>> event = ObjectRemovedEvent(c) >>> dispatchToSublocations(c, event)
Now, we should have seen all of the subobjects:
>>> seenreprs = sorted(map(repr, seen)) >>> seenreprs ['(C(11), C(1))', '(C(12), C(1))', '(L(111), C(1))', '(L(112), C(1))', '(L(121), C(1))', '(L(122), C(1))', '(L(123), C(1))', '(L(124), C(1))', '(L(13), C(1))']
We see that we get entries for each of the subobjects and that,for each entry, the event object is top object.
This suggests that location event handlers need to be aware that the objects they are called on and the event objects could be different.
- zope.container.contained.notifyContainerModified(object, *descriptions)[source]
Notify that the container was modified.
- zope.container.contained.setitem(container, setitemf, name, object)[source]
Helper function to set an item and generate needed events
This helper is needed, in part, because the events need to get published after the object has been added to the container.
If the item implements
IContained
, simply set its__parent__
and__name__
attributes:>>> class IItem(zope.interface.Interface): ... pass >>> @zope.interface.implementer(IItem) ... class Item(Contained): ... def setAdded(self, event): ... self.added = event ... def setMoved(self, event): ... self.moved = event
>>> from zope.lifecycleevent.interfaces import IObjectAddedEvent >>> from zope.lifecycleevent.interfaces import IObjectMovedEvent
>>> from zope import component >>> component.provideHandler(lambda obj, event: obj.setAdded(event), ... [IItem, IObjectAddedEvent]) >>> component.provideHandler(lambda obj, event: obj.setMoved(event), ... [IItem, IObjectMovedEvent])
>>> item = Item()
>>> container = {} >>> setitem(container, container.__setitem__, 'c', item) >>> container['c'] is item True >>> item.__parent__ is container True >>> item.__name__ 'c'
If we run this using the testing framework, we’ll use
getEvents
to track the events generated:>>> from zope.component.eventtesting import getEvents >>> from zope.lifecycleevent.interfaces import IObjectModifiedEvent
We have an added event:
>>> len(getEvents(IObjectAddedEvent)) 1 >>> event = getEvents(IObjectAddedEvent)[-1] >>> event.object is item True >>> event.newParent is container True >>> event.newName 'c' >>> event.oldParent >>> event.oldName
As well as a modification event for the container:
>>> len(getEvents(IObjectModifiedEvent)) 1 >>> getEvents(IObjectModifiedEvent)[-1].object is container 1
The item’s hooks have been called:
>>> item.added is event 1 >>> item.moved is event 1
We can suppress events and hooks by setting the
__parent__
and__name__
first:>>> item = Item() >>> item.__parent__, item.__name__ = container, 'c2' >>> setitem(container, container.__setitem__, 'c2', item) >>> len(container) 2 >>> len(getEvents(IObjectAddedEvent)) 1 >>> len(getEvents(IObjectModifiedEvent)) 1
>>> getattr(item, 'added', None) >>> getattr(item, 'moved', None)
If the item had a parent or name (as in a move or rename), we generate a move event, rather than an add event:
>>> setitem(container, container.__setitem__, 'c3', item) >>> len(container) 3 >>> len(getEvents(IObjectAddedEvent)) 1 >>> len(getEvents(IObjectModifiedEvent)) 2 >>> len(getEvents(IObjectMovedEvent)) 2
(Note that we have 2 move events because add are move events.)
We also get the move hook called, but not the add hook:
>>> event = getEvents(IObjectMovedEvent)[-1] >>> getattr(item, 'added', None) >>> item.moved is event 1
If we try to replace an item without deleting it first, we’ll get an error:
>>> setitem(container, container.__setitem__, 'c', []) Traceback (most recent call last): ... KeyError: 'c'
>>> del container['c'] >>> setitem(container, container.__setitem__, 'c', []) >>> len(getEvents(IObjectAddedEvent)) 2 >>> len(getEvents(IObjectModifiedEvent)) 3
If the object implements
ILocation
, but notIContained
, set it’s__parent__
and__name__
attributes and declare that it implementsIContained
:>>> from zope.location import Location >>> item = Location() >>> IContained.providedBy(item) 0 >>> setitem(container, container.__setitem__, 'l', item) >>> container['l'] is item 1 >>> item.__parent__ is container 1 >>> item.__name__ 'l' >>> IContained.providedBy(item) 1
We get new added and modification events:
>>> len(getEvents(IObjectAddedEvent)) 3 >>> len(getEvents(IObjectModifiedEvent)) 4
If the object doesn’t even implement
ILocation
, put aContainedProxy
around it:>>> item = [] >>> setitem(container, container.__setitem__, 'i', item) >>> container['i'] [] >>> container['i'] is item 0 >>> item = container['i'] >>> item.__parent__ is container 1 >>> item.__name__ 'i' >>> IContained.providedBy(item) 1
>>> len(getEvents(IObjectAddedEvent)) 4 >>> len(getEvents(IObjectModifiedEvent)) 5
We’ll get type errors if we give keys that aren’t unicode or ascii keys:
>>> setitem(container, container.__setitem__, 42, item) Traceback (most recent call last): ... TypeError: name not unicode or ascii string
>>> setitem(container, container.__setitem__, None, item) Traceback (most recent call last): ... TypeError: name not unicode or ascii string
>>> setitem(container, container.__setitem__, b'hello \xc8', item) Traceback (most recent call last): ... TypeError: name not unicode or ascii string
and we’ll get a value error of we give an empty string or unicode:
>>> setitem(container, container.__setitem__, '', item) Traceback (most recent call last): ... ValueError: empty names are not allowed
>>> setitem(container, container.__setitem__, '', item) Traceback (most recent call last): ... ValueError: empty names are not allowed
- zope.container.contained.uncontained(object, container, name=None)[source]
Clear the containment relationship between the object and the container.
If we run this using the testing framework, we’ll use
getEvents
to track the events generated:>>> from zope.component.eventtesting import getEvents >>> from zope.lifecycleevent.interfaces import IObjectModifiedEvent >>> from zope.lifecycleevent.interfaces import IObjectRemovedEvent
We’ll start by creating a container with an item:
>>> class Item(Contained): ... pass
>>> item = Item() >>> container = {'foo': item} >>> x, event = containedEvent(item, container, 'foo') >>> item.__parent__ is container 1 >>> item.__name__ 'foo'
Now we’ll remove the item. It’s parent and name are cleared:
>>> uncontained(item, container, 'foo') >>> item.__parent__ >>> item.__name__
We now have a new removed event:
>>> len(getEvents(IObjectRemovedEvent)) 1 >>> event = getEvents(IObjectRemovedEvent)[-1] >>> event.object is item 1 >>> event.oldParent is container 1 >>> event.oldName 'foo' >>> event.newParent >>> event.newName
As well as a modification event for the container:
>>> len(getEvents(IObjectModifiedEvent)) 1 >>> getEvents(IObjectModifiedEvent)[-1].object is container 1
Now if we call uncontained again:
>>> uncontained(item, container, 'foo')
We won’t get any new events, because __parent__ and __name__ are None:
>>> len(getEvents(IObjectRemovedEvent)) 1 >>> len(getEvents(IObjectModifiedEvent)) 1
But, if either the name or parent are not
None
and they are not the container and the old name, we’ll get a modified event but not a removed event.>>> item.__parent__, item.__name__ = container, None >>> uncontained(item, container, 'foo') >>> len(getEvents(IObjectRemovedEvent)) 1 >>> len(getEvents(IObjectModifiedEvent)) 2
>>> item.__parent__, item.__name__ = None, 'bar' >>> uncontained(item, container, 'foo') >>> len(getEvents(IObjectRemovedEvent)) 1 >>> len(getEvents(IObjectModifiedEvent)) 3
If one tries to delete a Broken object, we allow them to do just that.
>>> class Broken(object): ... __Broken_state__ = {} >>> broken = Broken() >>> broken.__Broken_state__['__name__'] = 'bar' >>> broken.__Broken_state__['__parent__'] = container >>> container['bar'] = broken >>> uncontained(broken, container, 'bar') >>> len(getEvents(IObjectRemovedEvent)) 2
BTree
This module provides a sample btree container implementation.
Directory
File-system representation adapters for containers
This module includes two adapters (adapter factories, really) for providing a file-system representation for containers:
noop
Factory that “adapts”
IContainer
toIWriteDirectory
. This is a lie, since it just returns the original object.Cloner
An
IDirectoryFactory
adapter that just clones the original object.
- class zope.container.directory.Cloner(context)[source]
Bases:
object
IContainer
tozope.filerepresentation.interfaces.IDirectoryFactory
adapter that clones.This adapter provides a factory that creates a new empty container of the same class as it’s context.
Folders
The standard Zope Folder.
- class zope.container.folder.Folder[source]
Bases:
BTreeContainer
The standard Zope Folder implementation.
Find Support
Ordered
Ordered container implementation.
- class zope.container.ordered.OrderedContainer[source]
Bases:
Persistent
,Contained
OrderedContainer
maintains entries’ order as added and moved.>>> oc = OrderedContainer() >>> int(IOrderedContainer.providedBy(oc)) 1 >>> len(oc) 0
- get(key, default=None)[source]
See
IOrderedContainer
.>>> oc = OrderedContainer() >>> oc['foo'] = 'bar' >>> oc.get('foo') 'bar' >>> oc.get('funky', 'No chance, dude.') 'No chance, dude.'
- has_key(key)
See
IOrderedContainer
.>>> oc = OrderedContainer() >>> oc['foo'] = 'bar' >>> int('foo' in oc) 1 >>> int('quux' in oc) 0
- items()[source]
See
IOrderedContainer
.>>> oc = OrderedContainer() >>> oc.keys() [] >>> oc['foo'] = 'bar' >>> oc.items() [('foo', 'bar')] >>> oc['baz'] = 'quux' >>> oc.items() [('foo', 'bar'), ('baz', 'quux')] >>> int(len(oc._order) == len(oc._data)) 1
- keys()[source]
See
IOrderedContainer
.>>> oc = OrderedContainer() >>> oc.keys() [] >>> oc['foo'] = 'bar' >>> oc.keys() ['foo'] >>> oc['baz'] = 'quux' >>> oc.keys() ['foo', 'baz'] >>> int(len(oc._order) == len(oc._data)) 1
- updateOrder(order)[source]
See
IOrderedContainer
.>>> oc = OrderedContainer() >>> oc['foo'] = 'bar' >>> oc['baz'] = 'quux' >>> oc['zork'] = 'grue' >>> oc.keys() ['foo', 'baz', 'zork'] >>> oc.updateOrder(['baz', 'foo', 'zork']) >>> oc.keys() ['baz', 'foo', 'zork'] >>> oc.updateOrder(['baz', 'zork', 'foo']) >>> oc.keys() ['baz', 'zork', 'foo'] >>> oc.updateOrder(['baz', 'zork', 'foo']) >>> oc.keys() ['baz', 'zork', 'foo'] >>> oc.updateOrder(('zork', 'foo', 'baz')) >>> oc.keys() ['zork', 'foo', 'baz'] >>> oc.updateOrder(['baz', 'zork']) Traceback (most recent call last): ... ValueError: Incompatible key set. >>> oc.updateOrder(['foo', 'bar', 'baz', 'quux']) Traceback (most recent call last): ... ValueError: Incompatible key set. >>> oc.updateOrder(1) Traceback (most recent call last): ... TypeError: order must be a tuple or a list. >>> oc.updateOrder('bar') Traceback (most recent call last): ... TypeError: order must be a tuple or a list. >>> oc.updateOrder(['baz', 'zork', 'quux']) Traceback (most recent call last): ... ValueError: Incompatible key set. >>> del oc['baz'] >>> del oc['zork'] >>> del oc['foo'] >>> len(oc) 0
Sample
Sample container implementation.
This is primarily for testing purposes.
It might be useful as a mix-in for some classes, but many classes will need a very different implementation.
Size
Adapters that give the size of an object.
Traversal
Traversal components for containers
- class zope.container.traversal.ContainerTraversable(container)[source]
Bases:
object
Traverses containers via
getattr
andget
.
- class zope.container.traversal.ContainerTraverser(container, request)[source]
Bases:
object
A traverser that knows how to look up objects by name in a container.
- class zope.container.traversal.ItemTraverser(container, request)[source]
Bases:
ContainerTraverser
A traverser that knows how to look up objects by name in an item container.