chromium / chromium / src.git / a43a9eaba800ac7a88b22e8ea6d1666c8dc28ab6 / . / third_party / bintrees / README.txt

Binary Tree Package | |

=================== | |

Abstract | |

======== | |

This package provides Binary- RedBlack- and AVL-Trees written in Python and Cython. | |

This Classes are much slower than the built-in dict class, but all | |

iterators/generators yielding data in sorted key order. | |

Source of Algorithms | |

-------------------- | |

AVL- and RBTree algorithms taken from Julienne Walker: http://eternallyconfuzzled.com/jsw_home.aspx | |

Trees written in Python (only standard library) | |

----------------------------------------------- | |

- *BinaryTree* -- unbalanced binary tree | |

- *AVLTree* -- balanced AVL-Tree | |

- *RBTree* -- balanced Red-Black-Tree | |

Trees written with C-Functions and Cython as wrapper | |

---------------------------------------------------- | |

- *FastBinaryTree* -- unbalanced binary tree | |

- *FastAVLTree* -- balanced AVL-Tree | |

- *FastRBTree* -- balanced Red-Black-Tree | |

All trees provides the same API, the pickle protocol is supported. | |

FastXTrees has C-structs as tree-node structure and C-implementation for low level | |

operations: insert, remove, get_value, max_item, min_item. | |

Constructor | |

~~~~~~~~~~~ | |

* Tree() -> new empty tree; | |

* Tree(mapping) -> new tree initialized from a mapping (requires only an items() method) | |

* Tree(seq) -> new tree initialized from seq [(k1, v1), (k2, v2), ... (kn, vn)] | |

Methods | |

~~~~~~~ | |

* __contains__(k) -> True if T has a key k, else False, O(log(n)) | |

* __delitem__(y) <==> del T[y], del[s:e], O(log(n)) | |

* __getitem__(y) <==> T[y], T[s:e], O(log(n)) | |

* __iter__() <==> iter(T) | |

* __len__() <==> len(T), O(1) | |

* __max__() <==> max(T), get max item (k,v) of T, O(log(n)) | |

* __min__() <==> min(T), get min item (k,v) of T, O(log(n)) | |

* __and__(other) <==> T & other, intersection | |

* __or__(other) <==> T | other, union | |

* __sub__(other) <==> T - other, difference | |

* __xor__(other) <==> T ^ other, symmetric_difference | |

* __repr__() <==> repr(T) | |

* __setitem__(k, v) <==> T[k] = v, O(log(n)) | |

* clear() -> None, remove all items from T, O(n) | |

* copy() -> a shallow copy of T, O(n*log(n)) | |

* discard(k) -> None, remove k from T, if k is present, O(log(n)) | |

* get(k[,d]) -> T[k] if k in T, else d, O(log(n)) | |

* is_empty() -> True if len(T) == 0, O(1) | |

* items([reverse]) -> generator for (k, v) items of T, O(n) | |

* keys([reverse]) -> generator for keys of T, O(n) | |

* values([reverse]) -> generator for values of T, O(n) | |

* pop(k[,d]) -> v, remove specified key and return the corresponding value, O(log(n)) | |

* popitem() -> (k, v), remove and return some (key, value) pair as a 2-tuple, O(log(n)) | |

* setdefault(k[,d]) -> T.get(k, d), also set T[k]=d if k not in T, O(log(n)) | |

* update(E) -> None. Update T from dict/iterable E, O(E*log(n)) | |

* foreach(f, [order]) -> visit all nodes of tree (0 = 'inorder', -1 = 'preorder' or +1 = 'postorder') and call f(k, v) for each node, O(n) | |

slicing by keys | |

~~~~~~~~~~~~~~~ | |

* itemslice(s, e) -> generator for (k, v) items of T for s <= key < e, O(n) | |

* keyslice(s, e) -> generator for keys of T for s <= key < e, O(n) | |

* valueslice(s, e) -> generator for values of T for s <= key < e, O(n) | |

* T[s:e] -> TreeSlice object, with keys in range s <= key < e, O(n) | |

* del T[s:e] -> remove items by key slicing, for s <= key < e, O(n) | |

start/end parameter: | |

* if 's' is None or T[:e] TreeSlice/iterator starts with value of min_key(); | |

* if 'e' is None or T[s:] TreeSlice/iterator ends with value of max_key(); | |

* T[:] is a TreeSlice which represents the whole tree; | |

TreeSlice is a tree wrapper with range check, and contains no references | |

to objects, deleting objects in the associated tree also deletes the object | |

in the TreeSlice. | |

* TreeSlice[k] -> get value for key k, raises KeyError if k not exists in range s:e | |

* TreeSlice[s1:e1] -> TreeSlice object, with keys in range s1 <= key < e1 | |

- new lower bound is max(s, s1) | |

- new upper bound is min(e, e1) | |

TreeSlice methods: | |

* items() -> generator for (k, v) items of T, O(n) | |

* keys() -> generator for keys of T, O(n) | |

* values() -> generator for values of T, O(n) | |

* __iter__ <==> keys() | |

* __repr__ <==> repr(T) | |

* __contains__(key)-> True if TreeSlice has a key k, else False, O(log(n)) | |

prev/succ operations | |

~~~~~~~~~~~~~~~~~~~~ | |

* prev_item(key) -> get (k, v) pair, where k is predecessor to key, O(log(n)) | |

* prev_key(key) -> k, get the predecessor of key, O(log(n)) | |

* succ_item(key) -> get (k,v) pair as a 2-tuple, where k is successor to key, O(log(n)) | |

* succ_key(key) -> k, get the successor of key, O(log(n)) | |

* floor_item(key) -> get (k, v) pair, where k is the greatest key less than or equal to key, O(log(n)) | |

* floor_key(key) -> k, get the greatest key less than or equal to key, O(log(n)) | |

* ceiling_item(key) -> get (k, v) pair, where k is the smallest key greater than or equal to key, O(log(n)) | |

* ceiling_key(key) -> k, get the smallest key greater than or equal to key, O(log(n)) | |

Heap methods | |

~~~~~~~~~~~~ | |

* max_item() -> get largest (key, value) pair of T, O(log(n)) | |

* max_key() -> get largest key of T, O(log(n)) | |

* min_item() -> get smallest (key, value) pair of T, O(log(n)) | |

* min_key() -> get smallest key of T, O(log(n)) | |

* pop_min() -> (k, v), remove item with minimum key, O(log(n)) | |

* pop_max() -> (k, v), remove item with maximum key, O(log(n)) | |

* nlargest(i[,pop]) -> get list of i largest items (k, v), O(i*log(n)) | |

* nsmallest(i[,pop]) -> get list of i smallest items (k, v), O(i*log(n)) | |

Set methods (using frozenset) | |

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |

* intersection(t1, t2, ...) -> Tree with keys *common* to all trees | |

* union(t1, t2, ...) -> Tree with keys from *either* trees | |

* difference(t1, t2, ...) -> Tree with keys in T but not any of t1, t2, ... | |

* symmetric_difference(t1) -> Tree with keys in either T and t1 but not both | |

* issubset(S) -> True if every element in T is in S | |

* issuperset(S) -> True if every element in S is in T | |

* isdisjoint(S) -> True if T has a null intersection with S | |

Classmethods | |

~~~~~~~~~~~~ | |

* fromkeys(S[,v]) -> New tree with keys from S and values equal to v. | |

Performance | |

=========== | |

Profiling with timeit(): 5000 unique random int keys, time in seconds | |

======================== ============= ============== ============== ============== | |

unbalanced Trees CPython 2.7.2 FastBinaryTree ipy 2.7.0 pypy 1.7.0 | |

======================== ============= ============== ============== ============== | |

build time 100x 7,55 0,60 2,51 0,29 | |

build & delete time 100x 13,34 1,48 4,45 0,47 | |

search 100x all keys 2,86 0,96 0,27 0,06 | |

======================== ============= ============== ============== ============== | |

======================== ============= ============== ============== ============== | |

AVLTrees CPython 2.7.2 FastAVLTree ipy 2.7.0 pypy 1.7.0 | |

======================== ============= ============== ============== ============== | |

build time 100x 22,66 0,65 10,45 1,29 | |

build & delete time 100x 36,71 1,47 20,89 3,02 | |

search 100x all keys 2,34 0,85 0,89 0,14 | |

======================== ============= ============== ============== ============== | |

======================== ============= ============== ============== ============== | |

RBTrees CPython 2.7.2 FastRBTree ipy 2.7.0 pypy 1.7.0 | |

======================== ============= ============== ============== ============== | |

build time 100x 14,78 0,65 4,43 0,49 | |

build & delete time 100x 39,34 1,63 12,43 1,32 | |

search 100x all keys 2,32 0,86 0,86 0,13 | |

======================== ============= ============== ============== ============== | |

News | |

==== | |

Version 1.0.1 February 2013 | |

* bug fixes | |

* refactorings by graingert | |

* skip useless tests for pypy | |

* new license: MIT License | |

* tested with CPython2.7, CPython3.2, CPython3.3, pypy-1.9, pypy-2.0-beta1 | |

* unified line endings to LF | |

* PEP8 refactorings | |

* added floor_item/key, ceiling_item/key methods, thanks to Dai Mikurube | |

Version 1.0.0 | |

* bug fixes | |

* status: 5 - Production/Stable | |

* removed useless TreeIterator() class and T.treeiter() method. | |

* patch from Max Motovilov to use Visual Studio 2008 for building C-extensions | |

Version 0.4.0 | |

* API change!!! | |

* full Python 3 support, also for Cython implementations | |

* removed user defined compare() function - keys have to be comparable! | |

* removed T.has_key(), use 'key in T' | |

* keys(), items(), values() generating 'views' | |

* removed iterkeys(), itervalues(), iteritems() methods | |

* replaced index slicing by key slicing | |

* removed index() and item_at() | |

* repr() produces a correct representation | |

* installs on systems without cython (tested with pypy) | |

* new license: GNU Library or Lesser General Public License (LGPL) | |

Installation | |

============ | |

from source:: | |

python setup.py install | |

Download | |

======== | |

http://bitbucket.org/mozman/bintrees/downloads | |

Documentation | |

============= | |

this README.txt | |

bintrees can be found on bitbucket.org at: | |

http://bitbucket.org/mozman/bintrees |