API Reference

Protocol APIs

Changed in version 4.8.0: Previously, ISized was defined here, but now it is imported from zope.interface.common.collections. The definition is the same.

Similarly, IReadSequence, previously defined here, has been replaced with zope.interface.common.sequence.IMinimalSequence.

Caution

Before version 4.8.0, most of these interfaces served as documentation only, and were not implemented by the classes of this package. For example, BTrees.OOBTree.BTree did not implement IBTree. (The exceptions were the IBTreeModule and IBTreeFamily families of interfaces and implementations.)

Beginning with version 4.8.0, objects implement the expected interface; the BTree classes implement IBTree, the set classes implement the appropriate set interface and so on.

interface BTrees.Interfaces.IKeyed[source]

Extends: BTrees.Interfaces.ICollection

has_key(key)

Check whether the object has an item with the given key.

Return a true value if the key is present, else a false value.

keys(min=None, max=None, excludemin=False, excludemax=False)

Return an IMinimalSequence containing the keys in the collection.

The type of the IMinimalSequence is not specified. It could be a list or a tuple or some other type.

All arguments are optional, and may be specified as keyword arguments, or by position.

If a min is specified, then output is constrained to keys greater than or equal to the given min, and, if excludemin is specified and true, is further constrained to keys strictly greater than min. A min value of None is ignored. If min is None or not specified, and excludemin is true, the smallest key is excluded.

If a max is specified, then output is constrained to keys less than or equal to the given max, and, if excludemax is specified and true, is further constrained to keys strictly less than max. A max value of None is ignored. If max is None or not specified, and excludemax is true, the largest key is excluded.

maxKey(key=None)

Return the maximum key.

If a key argument if provided and not None, return the largest key that is less than or equal to the argument. Raise an exception if no such key exists.

minKey(key=None)

Return the minimum key.

If a key argument if provided and not None, return the smallest key that is greater than or equal to the argument. Raise an exception if no such key exists.

interface BTrees.Interfaces.ISetMutable[source]

Extends: BTrees.Interfaces.IKeyed

insert(key)

Add the key (value) to the set.

If the key was already in the set, return 0, otherwise return 1.

remove(key)

Remove the key from the set.

Raises KeyError if key is not in the set.

update(seq): Add the items from the given sequence to the set.

__and__(other): Shortcut for intersection()

Added in version 4.8.0.

__iand__(other): As for set.intersection_update(): Update this object, keeping only elements found in both it and other.

Added in version 4.8.0.

__or__(other): Shortcut for union()

Added in version 4.8.0.

__ior__(other): As for set.update(): Update this object, adding elements from other.

Added in version 4.8.0.

__sub__(other): Shortcut for difference()

Added in version 4.8.0.

__isub__(other): As for set.difference_update(): Update this object, removing elements found in other.

Added in version 4.8.0.

isdisjoint(other): As for set.isdisjoint(): Return True if the set has no elements in common with other.

Added in version 4.8.0.

discard(key): As for set.discard(): Remove the key from the set, but only if it is present.

Added in version 4.8.0.

pop(): As for set.pop(): Remove and return an arbitrary element; raise KeyError if the object is empty.

Added in version 4.8.0.

__ixor__(other): As for set.symmetric_difference_update(): Update this object, keeping only elements found in either set but not in both.

Added in version 4.8.0.

interface BTrees.Interfaces.IKeySequence[source]

Extends: BTrees.Interfaces.IKeyed, zope.interface.common.collections.ISized

__getitem__(index)

Return the key in the given index position.

This allows iteration with for loops and use in functions, like map and list, that read sequences.

interface BTrees.Interfaces.IMinimalDictionary[source]

Extends: BTrees.Interfaces.IKeyed, zope.interface.common.collections.IMapping

Mapping operations.

Changed in version 4.8.0: Now extends zope.interface.common.collections.IMapping.

get(key, default)

Get the value associated with the given key.

Return the default if has_key() is false with the given key.

__getitem__(key)

Get the value associated with the given key.

Raise KeyError if has_key() is false with the given key.

__setitem__(key, value): Set the value associated with the given key.

__delitem__(key)

Delete the value associated with the given key.

Raise class:KeyError if has_key() is false with the given key.

values(min=None, max=None, excludemin=False, excludemax=False)

Return a minimal sequence containing the values in the collection.

Return value is an IMinimalSequence.

The type of the IMinimalSequence is not specified. It could be a list or a tuple or some other type.

All arguments are optional, and may be specified as keyword arguments, or by position.

If a min is specified, then output is constrained to values whose keys are greater than or equal to the given min, and, if excludemin is specified and true, is further constrained to values whose keys are strictly greater than min. A min value of None is ignored. If min is None or not specified, and excludemin is true, the value corresponding to the smallest key is excluded.

If a max is specified, then output is constrained to values whose keys are less than or equal to the given max, and, if excludemax is specified and true, is further constrained to values whose keys are strictly less than max. A max value of None is ignored. If max is None or not specified, and excludemax is true, the value corresponding to the largest key is excluded.

items(min=None, max=None, excludemin=False, excludemax=False)

Return an IMinimalSequence containing the items in the collection.

An item is a 2-tuple, a (key, value) pair.

The type of the IMinimalSequence is not specified. It could be a list or a tuple or some other type.

All arguments are optional, and may be specified as keyword arguments, or by position.

If a min is specified, then output is constrained to items whose keys are greater than or equal to the given min, and, if excludemin is specified and true, is further constrained to items whose keys are strictly greater than min. A min value of None is ignored. If min is None or not specified, and excludemin is true, the item with the smallest key is excluded.

If a max is specified, then output is constrained to items whose keys are less than or equal to the given max, and, if excludemax is specified and true, is further constrained to items whose keys are strictly less than *max. A max value of None is ignored. If max is None or not specified, and excludemax is true, the item with the largest key is excluded.

interface BTrees.Interfaces.IDictionaryIsh[source]

Extends: BTrees.Interfaces.IMinimalDictionary

update(collection)

Add the items from the given collection object to the collection.

The input collection must be a sequence of (key, value) 2-tuples, or an object with an ‘items’ method that returns a sequence of (key, value) pairs.

byValue(minValue)

Return a sequence of (value, key) pairs, sorted by value.

Values < minValue are omitted and other values are “normalized” by the minimum value. This normalization may be a noop, but, for integer values, the normalization is division.

setdefault(key, d)

D.setdefault(k, d) -> D.get(k, d), also set D[k]=d if k not in D.

Return the value like get() except that if key is missing, d is both returned and inserted into the dictionary as the value of k.

Note that, unlike as for Python’s dict.setdefault(), d is not optional. Python defaults d to None, but that doesn’t make sense for mappings that can’t have None as a value (for example, an IIBTree can have only integers as values).

pop(key, d)

D.pop(k[, d]) -> v, remove key and return the corresponding value.

If key is not found, d is returned if given, otherwise KeyError is raised.

popitem(): D.popitem() -> (k, v), remove and return some (key, value) pair as a 2-tuple; but raise KeyError if D is empty.

Added in version 4.8.0.

interface BTrees.Interfaces.IMerge[source]

Object with methods for merging sets, buckets, and trees.

These methods are supplied in modules that define collection classes with particular key and value types. The operations apply only to collections from the same module. For example, the BTrees.IIBTree.IIBTree.union() can only be used with IIBTree, IIBucket, IISet, and IITreeSet.

The number protocols methods __and__, __or__ and __sub__ are provided by all the data structures. They are shortcuts for intersection(), union() and difference().

The implementing module has a value type. The IOBTree and OOBTree modules have object value type. The IIBTree and OIBTree modules have integer value types. Other modules may be defined in the future that have other value types.

The individual types are classified into set (Set and TreeSet) and mapping (Bucket and BTree) types.

difference(c1, c2)

Return the keys or items in c1 for which there is no key in c2.

If c1 is None, then None is returned. If c2 is None, then c1 is returned.

If neither c1 nor c2 is None, the output is a Set if c1 is a Set or TreeSet, and is a Bucket if c1 is a Bucket or BTree.

While c1 must be one of those types, c2 can be any Python iterable returning the correct types of objects.

Changed in version 4.8.0: Add support for c2 to be an arbitrary iterable.

union(c1, c2)

Compute the Union of c1 and c2.

If c1 is None, then c2 is returned, otherwise, if c2 is None, then c1 is returned.

The output is a Set containing keys from the input collections.

c1 and c2 can be any Python iterables returning the correct type of objects.

Changed in version 4.8.0: Add support for arbitrary iterables.

intersection(c1, c2)

Compute the intersection of c1 and c2.

If c1 is None, then c2 is returned, otherwise, if c2 is None, then c1 is returned.

The output is a Set containing matching keys from the input collections.

c1 and c2 can be any Python iterables returning the correct type of objects.

Changed in version 4.8.0: Add support for arbitrary iterables.

interface BTrees.Interfaces.IIMerge[source]

Extends: BTrees.Interfaces.IMerge

Merge collections with integer value type.

A primary intent is to support operations with no or integer values, which are used as “scores” to rate indiviual keys. That is, in this context, a BTree or Bucket is viewed as a set with scored keys, using integer scores.

weightedUnion(c1, c2, weight1=1, weight2=1)

Compute the weighted union of c1 and c2.

If c1 and c2 are None, the output is (0, None).

If c1 is None and c2 is not None, the output is (weight2, c2).

If c1 is not None and c2 is None, the output is (weight1, c1).

Else, and hereafter, c1 is not None and c2 is not None.

If c1 and c2 are both sets, the output is 1 and the (unweighted) union of the sets.

Else the output is 1 and a Bucket whose keys are the union of c1 and c2’s keys, and whose values are:

v1*weight1 + v2*weight2

where:

  v1 is 0        if the key is not in c1
        1        if the key is in c1 and c1 is a set
        c1[key]  if the key is in c1 and c1 is a mapping

  v2 is 0        if the key is not in c2
        1        if the key is in c2 and c2 is a set
        c2[key]  if the key is in c2 and c2 is a mapping

Note that c1 and c2 must be collections.

weightedIntersection(c1, c2, weight1=1, weight2=1)

Compute the weighted intersection of c1 and c2.

If c1 and c2 are None, the output is (0, None).

If c1 is None and c2 is not None, the output is (weight2, c2).

If c1 is not None and c2 is None, the output is (weight1, c1).

Else, and hereafter, c1 is not None and c2 is not None.

If c1 and c2 are both sets, the output is the sum of the weights and the (unweighted) intersection of the sets.

Else the output is 1 and a Bucket whose keys are the intersection of c1 and c2’s keys, and whose values are:

v1*weight1 + v2*weight2

where:

  v1 is 1        if c1 is a set
        c1[key]  if c1 is a mapping

  v2 is 1        if c2 is a set
        c2[key]  if c2 is a mapping

Note that c1 and c2 must be collections.

interface BTrees.Interfaces.IMergeIntegerKey[source]

Extends: BTrees.Interfaces.IMerge

IMerge-able objects with integer keys.

Concretely, this means the types in IOBTree and IIBTree.

multiunion(seq)

Return union of (zero or more) integer sets, as an integer set.

seq is a sequence of objects each convertible to an integer set. These objects are convertible to an integer set:

An integer, which is added to the union.
A Set or TreeSet from the same module (for example, an BTrees.IIBTree.TreeSet for BTrees.IIBTree.multiunion()). The elements of the set are added to the union.
A Bucket or BTree from the same module (for example, an BTrees.IOBTree.IOBTree for BTrees.IOBTree.multiunion()). The keys of the mapping are added to the union.
Any iterable Python object that iterates across integers. This will be slower than the above types.

The union is returned as a Set from the same module (for example, BTrees.IIBTree.multiunion() returns an BTrees.IIBTree.IISet).

The point to this method is that it can run much faster than doing a sequence of two-input union() calls. Under the covers, all the integers in all the inputs are sorted via a single linear-time radix sort, then duplicates are removed in a second linear-time pass.

Changed in version 4.8.0: Add support for arbitrary iterables of integers.

BTree Family APIs

interface BTrees.Interfaces.ISet[source]

Extends: BTrees.Interfaces.ISetMutable, BTrees.Interfaces.IKeySequence

A set of unique items stored in a single persistent object.

interface BTrees.Interfaces.ITreeSet[source]

Extends: BTrees.Interfaces.ISetMutable

A set of unique items stored in a tree of persistent objects.

interface BTrees.Interfaces.IBTree[source]

Extends: BTrees.Interfaces.IDictionaryIsh

insert(key, value)

Insert a key and value into the collection.

If the key was already in the collection, then there is no change and 0 is returned.

If the key was not already in the collection, then the item is added and 1 is returned.

This method is here to allow one to generate random keys and to insert and test whether the key was there in one operation.

A standard idiom for generating new keys will be:

key = generate_key()
while not t.insert(key, value):
    key=generate_key()

__and__(other): Shortcut for intersection()

__or__(other): Shortcut for union()

__sub__(other): Shortcut for difference()

interface BTrees.Interfaces.IBTreeFamily[source]

the 64-bit or 32-bit family

IF: The IIntegerFloatBTreeModule for this family

II: The IIntegerIntegerBTreeModule for this family

IO: The IIntegerObjectBTreeModule for this family

IU: The IIntegerUnsignedBTreeModule for this family

UF: The IUnsignedFloatBTreeModule for this family

UI: The IUnsignedIntegerBTreeModule for this family

UO: The IUnsignedObjectBTreeModule for this family

UU: The IUnsignedUnsignedBTreeModule for this family

OI: The IObjectIntegerBTreeModule for this family

OO: The IObjectObjectBTreeModule for this family

OU: The IObjectUnsignedBTreeModule for this family

maxint: The maximum signed integer storable in this family

maxuint: The maximum unsigned integer storable in this family

minint: The minimum signed integer storable in this family

There are two families defined:

Module APIs

interface BTrees.Interfaces.IBTreeModule[source]

These are available in all modules (IOBTree, OIBTree, OOBTree, IIBTree, IFBTree, LFBTree, LOBTree, OLBTree, and LLBTree).

BTree

The IBTree for this module.

Also available as [prefix]BTree, as in IOBTree.

Bucket

The leaf-node data buckets used by the BTree.

(IBucket is not currently defined in this file, but is essentially IDictionaryIsh, with the exception of __nonzero__, as of this writing.)

Also available as [prefix]Bucket, as in IOBucket.

TreeSet

The ITreeSet for this module.

Also available as [prefix]TreeSet, as in IOTreeSet.

Set

The ISet for this module: the leaf-node data buckets used by the TreeSet.

Also available as [prefix]BTree, as in IOSet.

interface BTrees.Interfaces.IObjectObjectBTreeModule[source]

Extends: BTrees.Interfaces.IBTreeModule, BTrees.Interfaces.IMerge

Keys, or set values, are objects; values are also objects.

Object keys (and set values) must sort reliably (for instance, not on object id)! Homogenous key types recommended.

Note that there’s no family attribute; all families include the OO flavor of BTrees.

Describes OOBTree

interface BTrees.Interfaces.IIntegerObjectBTreeModule[source]

Extends: BTrees.Interfaces._IMergeBTreeModule

Keys, or set values, are signed ints; values are objects.

Describes IOBTree and LOBTree.

interface BTrees.Interfaces.IObjectIntegerBTreeModule[source]

Extends: BTrees.Interfaces._IMergeBTreeModule

Keys, or set values, are objects; values are signed ints.

Object keys (and set values) must sort reliably (for instance, not on object id)! Homogenous key types recommended.

Describes OIBTree and OLBTree.

interface BTrees.Interfaces.IIntegerIntegerBTreeModule[source]

Extends: BTrees.Interfaces._IMergeBTreeModule, BTrees.Interfaces.IMergeIntegerKey

Keys, or set values, are signed integers; values are signed integers.

Describes IIBTree and LLBTree

interface BTrees.Interfaces.IIntegerFloatBTreeModule[source]

Extends: BTrees.Interfaces._IMergeBTreeModule

Keys, or set values, are signed ints; values are floats.

Describes IFBTree and LFBTree

API Reference

Protocol APIs

BTree Family APIs

Module APIs

Utilities

BTree Data Structure Variants

Integer Keys

Float Values

Integer Values

Object Values

Unsigned Integer Values

Long Integer Keys

Float Values

Long Integer Values

Object Values

Quad Unsigned Integer Values

Object Keys

Integer Values

Long Integer Values

Object Values

Quad Unsigned Integer Values

Unsigned Integer Values

Quad Unsigned Integer Keys

Float Values

Long Integer Values

Object Values

Quad Unsigned Integer Values

Unsigned Integer Keys

Float Values

Integer Values

Object Values

Unsigned Integer Values