/hTSrSSKrSSKJrJr SSKJr "SS\5rSr Sr S/r g) zh Class for representing hierarchical language structures, such as syntax trees and morphological trees. N) Nonterminal Production) deprecatedc\rSrSrSrS7SjrSrSrSrSr S r S r S r S r S rSrSrSrSr\"S5S5r\"S5S5r\"\\5rSrSrSrSrSrS8SjrS7SjrSrSr Sr!S r"S9S!jr#S:S"jr$S;S#jr%\&S$5r'S%r(S&r)SS.jr1S/r2S0r3S1r4S2r5S?S3jr6S4r7S5r8S6r9g)@Treea A Tree represents a hierarchical grouping of leaves and subtrees. For example, each constituent in a syntax tree is represented by a single Tree. A tree's children are encoded as a list of leaves and subtrees, where a leaf is a basic (non-tree) value; and a subtree is a nested Tree. >>> from nltk.tree import Tree >>> print(Tree(1, [2, Tree(3, [4]), 5])) (1 2 (3 4) 5) >>> vp = Tree('VP', [Tree('V', ['saw']), ... Tree('NP', ['him'])]) >>> s = Tree('S', [Tree('NP', ['I']), vp]) >>> print(s) (S (NP I) (VP (V saw) (NP him))) >>> print(s[1]) (VP (V saw) (NP him)) >>> print(s[1,1]) (NP him) >>> t = Tree.fromstring("(S (NP I) (VP (V saw) (NP him)))") >>> s == t True >>> t[1][1].set_label('X') >>> t[1][1].label() 'X' >>> print(t) (S (NP I) (VP (V saw) (X him))) >>> t[0], t[1,1] = t[1,1], t[0] >>> print(t) (S (X him) (VP (V saw) (NP I))) The length of a tree is the number of children it has. >>> len(t) 2 The set_label() and label() methods allow individual constituents to be labeled. For example, syntax trees use this label to specify phrase tags, such as "NP" and "VP". Several Tree methods use "tree positions" to specify children or descendants of a tree. Tree positions are defined as follows: - The tree position *i* specifies a Tree's *i*\ th child. - The tree position ``()`` specifies the Tree itself. - If *p* is the tree position of descendant *d*, then *p+i* specifies the *i*\ th child of *d*. I.e., every tree position is either a single index *i*, specifying ``tree[i]``; or a sequence *i1, i2, ..., iN*, specifying ``tree[i1][i2]...[iN]``. Construct a new tree. This constructor can be called in one of two ways: - ``Tree(label, children)`` constructs a new tree with the specified label and list of children. - ``Tree.fromstring(s)`` constructs a new tree by parsing the string ``s``. NcUc![S[U5R-5e[U[5(a![S[U5R-5e[ R X5 Xlg)Nz)%s: Expected a node value and child list z.%s() argument 2 should be a list, not a string) TypeErrortype__name__ isinstancestrlist__init___label)selfnodechildrens F/var/www/auris/envauris/lib/python3.13/site-packages/nltk/tree/tree.pyr Tree.__init__\sm  ;d4j>Q>QQ # & &:../  MM$ )KcURURL=(a/ UR[U54UR[U54:H$N) __class__rrrothers r__eq__ Tree.__eq__nsD~~0 dkk4:5N LL KS 6  rcp[U[5(d-URRURR:$URURLa/UR[ U54UR[ U54:$URRURR:$r)r rrr rrrs r__lt__ Tree.__lt__ts%&&>>**U__-E-EE E ^^u .KKd, d5k/JJ J>>**U__-E-EE Erc X:X+$rrs r Tree.sT!2rc*X:=(d X:H(+$rr#rs rr$r%sdl&Cdm!Drc X:=(d X:H$rr#rs rr$r%s!>!>rc X:+$rr#rs rr$r%sT!1rc[S5eNz$Tree does not support multiplicationr rvs r__mul__ Tree.__mul__>??rc[S5er*r+r,s r__rmul__ Tree.__rmul__r0rc[S5eNzTree does not support additionr+r,s r__add__ Tree.__add__899rc[S5er5r+r,s r__radd__ Tree.__radd__r8rcp[U[[45(a[R X5$[U[[ 45(a4[ U5S:XaU$[ U5S:XaXS$XSUSS$[[U5R<S[U5R<35e)Nr indices must be integers, not ) r intslicer __getitem__tuplelenr r r rindexs rrATree.__getitem__s ec5\ * *##D0 0 e} - -5zQ Uq!H~%!H~eABi00:&&U (<(<> rc[U[[45(a[R XU5$[U[[ 45(a?[ U5S:Xa [S5e[ U5S:XaX US'gX USUSS'g[[U5R<S[U5R<35e)Nrz,The tree position () may not be assigned to.r=r>) r r?r@r __setitem__rBrC IndexErrorr r r )rrEvalues rrHTree.__setitem__s ec5\ * *##D7 7 e} - -5zQ !RSSUq!&U1X,1U1XuQRy):&&U (<(<> rc~[U[[45(a[R X5$[U[[ 45(a;[ U5S:Xa [S5e[ U5S:XaXS gXSUSS g[[U5R<S[U5R<35e)Nrz(The tree position () may not be deleted.r=r>) r r?r@r __delitem__rBrCrIr r r rDs rrMTree.__delitem__s ec5\ * *##D0 0 e} - -5zQ !KLLUqqNqN59-:&&U (<(<> rzUse label() insteadcg)zIOutdated method to access the node value; use the label() method instead.Nr#rs r _get_nodeTree._get_noderzUse set_label() insteadcg)zJOutdated method to set the node value; use the set_label() method instead.Nr#)rrJs r _set_nodeTree._set_noderSrcUR$)z Return the node label of the tree. >>> t = Tree.fromstring('(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))') >>> t.label() 'S' :return: the node label (typically a string) :rtype: any rrPs rlabel Tree.labels{{rcXlg)a/ Set the node label of the tree. >>> t = Tree.fromstring("(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))") >>> t.set_label("T") >>> print(t) (T (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat)))) :param label: the node label (typically a string) :type label: any NrX)rrYs r set_labelTree.set_labels  rc/nUHJn[U[5(a!URUR55 M9UR U5 ML U$)aR Return the leaves of the tree. >>> t = Tree.fromstring("(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))") >>> t.leaves() ['the', 'dog', 'chased', 'the', 'cat'] :return: a list containing this tree's leaves. The order reflects the order of the leaves in the tree's hierarchical structure. :rtype: list )r rextendleavesappend)rr`childs rr` Tree.leavessEE%&& elln- e$   rcR[UR5UR55$)au Return a flat version of the tree, with all non-root non-terminals removed. >>> t = Tree.fromstring("(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))") >>> print(t.flatten()) (S the dog chased the cat) :return: a tree consisting of this tree's root connected directly to its leaves, omitting all intervening non-terminal nodes. :rtype: Tree )rrYr`rPs rflatten Tree.flattensDJJL$++-00rcSnUH?n[U[5(a[XR55nM3[US5nMA SU-$)a Return the height of the tree. >>> t = Tree.fromstring("(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))") >>> t.height() 5 >>> print(t[0,0]) (D the) >>> t[0,0].height() 2 :return: The height of this tree. The height of a tree containing no children is 1; the height of a tree containing only leaves is 2; and the height of any other tree is one plus the maximum of its children's heights. :rtype: int rr=)r rmaxheight)rmax_child_heightrbs rri Tree.heightsO&E%&&#&'7#H #&'7#;  ###rc<^/nUS;aURS5 [U5H[umn[U[5(a.UR U5nUR U4SjU55 MIURT45 M] US;aURS5 U$)a >>> t = Tree.fromstring("(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))") >>> t.treepositions() # doctest: +ELLIPSIS [(), (0,), (0, 0), (0, 0, 0), (0, 1), (0, 1, 0), (1,), (1, 0), (1, 0, 0), ...] >>> for pos in t.treepositions('leaves'): ... t[pos] = t[pos][::-1].upper() >>> print(t) (S (NP (D EHT) (N GOD)) (VP (V DESAHC) (NP (D EHT) (N TAC)))) :param order: One of: ``preorder``, ``postorder``, ``bothorder``, ``leaves``. )preorder bothorderr#c30># UH nT4U-v M g7frr#).0pis r %Tree.treepositions..Bs <8a!8s) postorderrn)ra enumerater r treepositionsr_)rorder positionsrbchildposrrs @rrwTree.treepositions/s - -   R !$HAu%&& ..u5  <8 <<  !& ( . .   R rc## U(a U"U5(aUv UH3n[U[5(dMURU5ShvN M5 gN 7f)a Generate all the subtrees of this tree, optionally restricted to trees matching the filter function. >>> t = Tree.fromstring("(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))") >>> for s in t.subtrees(lambda t: t.height() == 2): ... print(s) (D the) (N dog) (V chased) (D the) (N cat) :type filter: function :param filter: the function to filter all local trees N)r rsubtrees)rfilterrbs rr} Tree.subtreesIsC"JE%&& >>&1111s1AA A Ac[UR[5(d [S5e[ [ UR5[ U55/nUH,n[U[5(dMXR5- nM. U$)a Generate the productions that correspond to the non-terminal nodes of the tree. For each subtree of the form (P: C1 C2 ... Cn) this produces a production of the form P -> C1 C2 ... Cn. >>> t = Tree.fromstring("(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))") >>> t.productions() # doctest: +NORMALIZE_WHITESPACE [S -> NP VP, NP -> D N, D -> 'the', N -> 'dog', VP -> V NP, V -> 'chased', NP -> D N, D -> 'the', N -> 'cat'] :rtype: list(Production) zPProductions can only be generated from trees having node labels that are strings) r rrr rr _child_namesr productions)rprodsrbs rrTree.productions`ss$++s++b K 4l46HIJE%&&**,, rc/nUHUn[U[5(a!URUR55 M9UR X R 45 MW U$)a Return a sequence of pos-tagged words extracted from the tree. >>> t = Tree.fromstring("(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))") >>> t.pos() [('the', 'D'), ('dog', 'N'), ('chased', 'V'), ('the', 'D'), ('cat', 'N')] :return: a list of tuples containing leaves and pre-terminals (part-of-speech tags). The order reflects the order of the leaves in the tree's hierarchical structure. :rtype: list(tuple) )r rr_posrar)rrrbs rrTree.posysLE%&& 599;' E;;/0   rc>US:a [S5eUS4/nU(avUR5up4[U[5(dUS:XaU$US-nO8[ [ U5S- SS5HnUR X5XE4-45 M U(aMv[S5e)z :return: The tree position of the ``index``-th leaf in this tree. I.e., if ``tp=self.leaf_treeposition(i)``, then ``self[tp]==self.leaves()[i]``. :raise IndexError: If this tree contains fewer than ``index+1`` leaves, or if ``index<0``. rzindex must be non-negativer#r=z-index must be less than or equal to len(self))rIpopr rrangerCra)rrEstackrJtreeposrrs rleaf_treepositionTree.leaf_treepositions 199: : "YY[NEeT**A:"NQJEs5zA~r26ALL%(GdN!;<7eHIIrcX!::a [S5eURU5nURUS- 5n[[U55H#nU[U5:Xd X5XE:wdMUSUs $ U$)z :return: The tree position of the lowest descendant of this tree that dominates ``self.leaves()[start:end]``. :raise ValueError: if ``end <= start`` zend must be greater than startr=N) ValueErrorrrrC)rstartend start_treepos end_treeposrrs rtreeposition_spanning_leaves!Tree.treeposition_spanning_leavess} <=> >..u5 ,,S1W5 s=)*AC $$ (8KN(J$Ra((+rc$SSKJn U"XX#XE5 g)aY This method can modify a tree in three ways: 1. Convert a tree into its Chomsky Normal Form (CNF) equivalent -- Every subtree has either two non-terminals or one terminal as its children. This process requires the creation of more"artificial" non-terminal nodes. 2. Markov (vertical) smoothing of children in new artificial nodes 3. Horizontal (parent) annotation of nodes :param factor: Right or left factoring method (default = "right") :type factor: str = [left|right] :param horzMarkov: Markov order for sibling smoothing in artificial nodes (None (default) = include all siblings) :type horzMarkov: int | None :param vertMarkov: Markov order for parent smoothing (0 (default) = no vertical annotation) :type vertMarkov: int | None :param childChar: A string used in construction of the artificial nodes, separating the head of the original subtree from the child nodes that have yet to be expanded (default = "|") :type childChar: str :param parentChar: A string used to separate the node representation from its vertical annotation :type parentChar: str r)chomsky_normal_formN)nltk.tree.transformsr)rfactor horzMarkov vertMarkov childChar parentCharrs rrTree.chomsky_normal_forms> =D*)Xrc$SSKJn U"XX#U5 g)a This method modifies the tree in three ways: 1. Transforms a tree in Chomsky Normal Form back to its original structure (branching greater than two) 2. Removes any parent annotation (if it exists) 3. (optional) expands unary subtrees (if previously collapsed with collapseUnary(...) ) :param expandUnary: Flag to expand unary or not (default = True) :type expandUnary: bool :param childChar: A string separating the head node from its children in an artificial node (default = "|") :type childChar: str :param parentChar: A string separating the node label from its parent annotation (default = "^") :type parentChar: str :param unaryChar: A string joining two non-terminals in a unary production (default = "+") :type unaryChar: str r)un_chomsky_normal_formN)rr)r expandUnaryrr unaryCharrs rrTree.un_chomsky_normal_forms* @t)Src"SSKJn U"XX#5 g)a Collapse subtrees with a single child (ie. unary productions) into a new non-terminal (Tree node) joined by 'joinChar'. This is useful when working with algorithms that do not allow unary productions, and completely removing the unary productions would require loss of useful information. The Tree is modified directly (since it is passed by reference) and no value is returned. :param collapsePOS: 'False' (default) will not collapse the parent of leaf nodes (ie. Part-of-Speech tags) since they are always unary productions :type collapsePOS: bool :param collapseRoot: 'False' (default) will not modify the root production if it is unary. For the Penn WSJ treebank corpus, this corresponds to the TOP -> productions. :type collapseRoot: bool :param joinChar: A string used to connect collapsed node values (default = "+") :type joinChar: str r)collapse_unaryN)rr)r collapsePOS collapseRootjoinCharrs rrTree.collapse_unarys& 8t,Arc[U[5(a3UVs/sHo RU5PM nnU"URU5$U$s snf)z Convert a tree between different subtypes of Tree. ``cls`` determines which class will be used to encode the new tree. :type tree: Tree :param tree: The tree that should be converted. :return: The new Tree. )r rconvertr)clstreerbrs rr Tree.convertsG dD ! !8<=u E*H=t{{H- -K>sA c"UR5$rcopyrPs r__copy__ Tree.__copy__$syy{rc URSS9$)NTdeepr)rmemos r __deepcopy__Tree.__deepcopy__'syydy##rc|U(d[U5"URU5$[U5RU5$r)r rr)rrs rr Tree.copy*s/:dkk40 0:%%d+ +rcSSKJn U$)Nr) ImmutableTree)nltk.tree.immutabler)rrs r _frozen_classTree._frozen_class0s 5rcUR5nUcURU5nODURSS9nURS5HnU"X45X4'M URU5n[ U5 U$)NTrr`)rrrrwhash)r leaf_freezer frozen_classnewcopyrs rfreeze Tree.freeze5su))+  "**40GiiTi*G,,X6+GL9 7"**73G W rc [U[5(a[U5S:wa [S5e[R "SU5(a [S5eUup[R "U5[R "U 5pUcSU U S3nUcSU U S3n[R"U <SU<S U <S U<S 35n S/4/n U RU5GHKnUR5nUS U:Xai[U 5S :Xa'[U S S 5S :aURXS5 US SR5nUbU"U5nU RU/45 MX:Xa}[U 5S :Xa:[U S S 5S :XaURXU5 OURXS5 U R5unnU SS RU"UU55 GM[U 5S :XaURXU5 UbU"U5nU SS RU5 GMN [U 5S :aURUSU 5 OK[U S S 5S :XaURUSU5 O"U S S be[U S S 5S :XdeU S S S nU(a$URS:Xa[U5S :XaUS nU$)a Read a bracketed tree string and return the resulting tree. Trees are represented as nested brackettings, such as:: (S (NP (NNP John)) (VP (V runs))) :type s: str :param s: The string to read :type brackets: str (length=2) :param brackets: The bracket characters used to mark the beginning and end of trees and subtrees. :type read_node: function :type read_leaf: function :param read_node, read_leaf: If specified, these functions are applied to the substrings of ``s`` corresponding to nodes and leaves (respectively) to obtain the values for those nodes and leaves. They should have the following signature: read_node(str) -> value For example, these functions could be used to process nodes and leaves whose values should be some type other than string (such as ``FeatStruct``). Note that by default, node strings and leaf strings are delimited by whitespace and brackets; to override this default, use the ``node_pattern`` and ``leaf_pattern`` arguments. :type node_pattern: str :type leaf_pattern: str :param node_pattern, leaf_pattern: Regular expression patterns used to find node and leaf substrings in ``s``. By default, both nodes patterns are defined to match any sequence of non-whitespace non-bracket characters. :type remove_empty_top_bracketing: bool :param remove_empty_top_bracketing: If the resulting tree has an empty node label, and is length one, then return its single child instead. This is useful for treebank trees, which sometimes contain an extra level of bracketing. :return: A tree corresponding to the string representation ``s``. If this class method is called using a subclass of Tree, then it will return a tree of that type. :rtype: Tree z"brackets must be a length-2 stringz\szwhitespace brackets not allowedNz[^\sz]+z\s*(z)?|z|()rr= end-of-stringr)r rrCr researchescapecompilefinditergroup _parse_errorlstriprarr)rsbrackets read_node read_leaf node_pattern leaf_patternremove_empty_top_bracketingopen_bclose_b open_pattern close_patterntoken_rermatchtokenrYrrs r fromstringTree.fromstringEsx(C((CMQ,>@A A 99UH % %=> >"')yy'8"))G:Lm  "<.rBL  "<.rBL::\=, H   &&q)EKKMEQx6!u:?s58A;'7!';$$Q?ab ((*(%e,E eR[)!u:?58A;'1,((6:((?C"'))+xb ! ##Cx$89u:?$$Qv6(%e,Eb ! ##E*3*8 u:>   Q 9 q!  "   Q 88A;& &&uQx{#q( ((Qx{1~ '4;;"+<Ta7D rcUS:Xa [U5SpTOUR5UR5pTSURUUSU4-nUR SS5R SS5nUn[U5US-:a USUS-S -nUS:a S XS- S-nS nUS R S USS U--5- n[ U5e)z Display a friendly error message when parsing a tree string fails. :param s: The string we're parsing. :param match: regexp match of the problem token. :param expecting: what we expected to see instead. rz0%s.read(): expected %r but got %r %sat index %d.z    Nz... z {}"{}" {}^z )rCrrr replaceformatr)rrr expectingrrmsgoffsets rrTree._parse_errors O #Q A LL     E   IIdC ( (s 3 q6C"H *C"H %A 8(* %AF %%h3"v+3FGGorc [U5[:Xa\[U5S:aL[US5n[U5S:a-[ X!SSVs/sHo0R U5PM sn5$U$ggs snf)z :type l: list :param l: a tree represented as nested lists :return: A tree corresponding to the list representation ``l``. :rtype: Tree Convert nested lists to a NLTK Tree rr=N)r rrCreprrfromlist)rlrYrbs rr Tree.fromlistsj 7d?s1vz1JE1vzEqrU#KUELL$7U#KLL *?$Ls A1 c SSKJn U"U5 g)z@ Open a new window containing a graphical diagram of this tree. r) draw_treesN)nltk.draw.treer)rrs rdraw Tree.draws .4rc RSSKJn [U"XU5R"S0UD6US9 g)z Pretty-print this tree as ASCII or Unicode art. For explanation of the arguments, see the documentation for `nltk.tree.prettyprinter.TreePrettyPrinter`. r)TreePrettyPrinterfileNr#)nltk.tree.prettyprinterrprinttext)rsentence highlightstreamkwargsrs r pretty_printTree.pretty_prints( >  :??I&IPVWrcSRSU55nSR[U5R[ UR 5U5$)Nz, c38# UHn[U5v M g7fr)r)rpcs rrs Tree.__repr__..s3dT!WWdsz {}({}, [{}]))joinrr r rr)rchildstrs r__repr__ Tree.__repr__sE993d33$$ J       rc:SSKJn U"U5R5$)Nr) draw_tree)svglingr _repr_svg_)rrs rrTree._repr_svg_ s%))++rc"UR5$r)pformatrPs r__str__ Tree.__str__s||~rc ZSU;a USnUS OSn[UR"S0UD6US9 g)z8 Print a string representation of this Tree to 'stream' rNrr#)rr)rrrs rpprint Tree.pprints9 v H%Fx F dll$V$62rc URX4U5n[U5U-U:aU$[UR[5(aUSURU3nOUS[ UR5U3nUHn[U[ 5(a'USSUS---URXS-X4U5-- nM?[U[5(a"USSUS---SRU5-- nMv[U[5(aU(dUSSUS---SU--- nMUSSUS---[ U5-- nM XdS-$)a :return: A pretty-printed string representation of this tree. :rtype: str :param margin: The right margin at which to do line-wrapping. :type margin: int :param indent: The indentation level at which printing begins. This number is used to decide how far to indent subsequent lines. :type indent: int :param nodesep: A string that is used to separate the node from the children. E.g., the default value ``':'`` gives trees like ``(S: (NP: I) (VP: (V: saw) (NP: it)))``. rrrr/%sr=) _pformat_flatrCr rrrrrrBr)rmarginindentnodesepparensquotesrrbs rr Tree.pformat!sZ   w 7 q6F?V #H dkk3 ' '!9+dkk]7)4A!9+d4;;/0 :AE%&&VaZ()mmFQJPQ E5))TC6A:..%@@E3''TC6A:..==TC6A:..e<<!9}rc[R"S5nURSSSS9nS[R"USU5-$)aH Returns a representation of the tree compatible with the LaTeX qtree package. This consists of the string ``\Tree`` followed by the tree represented in bracketed notation. For example, the following result was generated from a parse tree of the sentence ``The announcement astounded us``:: \Tree [.I'' [.N'' [.D The ] [.N' [.N announcement ] ] ] [.I' [.V'' [.V' [.V astounded ] [.N'' [.N' [.N us ] ] ] ] ] ] ] See https://www.ling.upenn.edu/advice/latex.html for the LaTeX style file for the qtree package. :return: A latex qtree representation of this tree. :rtype: str z([#\$%&~_\{\}])r)z[.z ])r$r%r&z\Tree z\\\1)rrrsub)rreserved_charsrs rpformat_latex_qtreeTree.pformat_latex_qtreeIs?$$67,,aL,I266.'7CCCrc/nUHn[U[5(a#URURXU55 M;[U[5(a"URSR U55 Mr[U[ 5(aU(dURSU-5 MUR[U55 M [UR[ 5(a4SRUSURUSR U5US5$SRUS[UR5USR U5US5$)Nr r!z {}{}{} {}{}rrr=) r rrar"rBrrrrr)rr%r&r' childstrsrbs rr"Tree._pformat_flat`s E%&&  !4!4Wf!MNE5))  %1E3''  .  e- dkk3 ' ' ''q  #q  !''q T[[!#q  rrXr)rm)rightNr|^)Tr3r4+)FFr5)F)()NNNNF)Nr#N)Frrr6F):r __module__ __qualname____firstlineno____doc__rrr __ne____gt____le____ge__r.r2r6r:rArHrMrrQrUpropertyrrYr\r`rerirwr}rrrrrrr classmethodrrrrrrrrrrr rrrrrr-r"__static_attributes__r#rrrrs=~ $ F3F DF >F 1F @@::  &%&X'X)*Y+Y Iy )D  * 1$642.2(J40 !YHJMT2B6  $,   $)vvp<*X ,  3&PD.rrc/nUHOn[U[5(a&UR[UR55 M>URU5 MQ U$r)r rrarr)rnamesrbs rrr}sF E eT " " LLU\\2 3 LL   LrcSSKJnJn SnURU5n[ S5 [ U5 [ UR 55 [ S5 [ UR 55 [ US5 [ US5 [ UR55 [ UR55 [ US5 [ US5 [ US5 USnURSURS 55 [ S 5 [ U5 URS 5US '[ U5 [ 5 [ S 5 UR5 [ U5 [ S5 UR5 [ U5 [ 5 U"SSS/SS9n[ S5 [ U5 [ 5 URUR55n[ S5 [ U5 [ 5 [ S5 [ UR55 [ 5 [ S5 [ UR55 [ 5 URS5 [ U5 g)z A demonstration showing how Trees and Trees can be used. This demonstration creates a Tree, and loads a Tree from the Treebank corpus, and shows the results of calling several of their methods. r)ProbabilisticTreerzA(S (NP (DT the) (NN cat)) (VP (VBD ate) (NP (DT a) (NN cookie))))z#Convert bracketed string into tree:zDisplay tree properties:r=)r=r=)r=r=rz(JJ big)zTree modification:z (NN cake))r=r=r=zCollapse unary:zChomsky normal form:xyzg?)probzProbabilistic Tree:z0Convert tree to bracketed string and back again:z LaTeX output:zProduction output:)testN)nltkrFrrrrrYrir`insertrrrr-rr\)rFrrtthe_catpts rdemorRs- LA A /0 !H !**, $% !'') !A$K !A$K !((* !((* !A$K !D'N !G*dG NN1dooj12  !H-AgJ !H G  !H ! !H G 3c  5B   "I G  $A <= !H G / !   !" G  !--/ GKK  !Hr) r;r nltk.grammarrrnltk.internalsrrrrrR__all__r#rrrVs<  0%^ 4^ BE R  r