我们从Python开源项目中，提取了以下50个代码示例，用于说明如何使用nltk.Nonterminal()。
def __init__(self, parent, cfg=None, set_cfg_callback=None): self._parent = parent if cfg is not None: self._cfg = cfg else: self._cfg = CFG(Nonterminal('S'), []) self._set_cfg_callback = set_cfg_callback self._highlight_matching_nonterminals = 1 # Create the top-level window. self._top = Toplevel(parent) self._init_bindings() self._init_startframe() self._startframe.pack(side='top', fill='x', expand=0) self._init_prodframe() self._prodframe.pack(side='top', fill='both', expand=1) self._init_buttons() self._buttonframe.pack(side='bottom', fill='x', expand=0) self._textwidget.focus()
def _markproduction(self, prod, tree=None): if tree is None: tree = self._tree for i in range(len(tree.subtrees())-len(prod.rhs())): if tree['color', i] == 'white': self._markproduction for j, node in enumerate(prod.rhs()): widget = tree.subtrees()[i+j] if (isinstance(node, Nonterminal) and isinstance(widget, TreeSegmentWidget) and node.symbol == widget.label().text()): pass # matching nonterminal elif (isinstance(node, compat.string_types) and isinstance(widget, TextWidget) and node == widget.text()): pass # matching nonterminal else: break else: # Everything matched! print('MATCH AT', i) #////////////////////////////////////////////////// # Grammar #//////////////////////////////////////////////////
def _parse_productions(self): """ Parse the current contents of the textwidget buffer, to create a list of productions. """ productions = [] # Get the text, normalize it, and split it into lines. text = self._textwidget.get('1.0', 'end') text = re.sub(self.ARROW, '->', text) text = re.sub('\t', ' ', text) lines = text.split('\n') # Convert each line to a CFG production for line in lines: line = line.strip() if line=='': continue productions += _read_cfg_production(line) #if line.strip() == '': continue #if not CFGEditor._PRODUCTION_RE.match(line): # raise ValueError('Bad production string %r' % line) # #(lhs_str, rhs_str) = line.split('->') #lhs = Nonterminal(lhs_str.strip()) #rhs = [] #def parse_token(match, rhs=rhs): # token = match.group() # if token[0] in "'\"": rhs.append(token[1:-1]) # else: rhs.append(Nonterminal(token)) # return '' #CFGEditor._TOKEN_RE.sub(parse_token, rhs_str) # #productions.append(Production(lhs, *rhs)) return productions
def _item_repr(self, item): contents = [] contents.append(('%s\t' % item.lhs(), 'nonterminal')) contents.append((self.ARROW, 'arrow')) for elt in item.rhs(): if isinstance(elt, Nonterminal): contents.append((' %s' % elt.symbol(), 'nonterminal')) else: contents.append((' %r' % elt, 'terminal')) return contents ###################################################################### # CFG Editor ######################################################################
def _apply(self, *e): productions = self._parse_productions() start = Nonterminal(self._start.get()) cfg = CFG(start, productions) if self._set_cfg_callback is not None: self._set_cfg_callback(cfg)
def demo2(): from nltk import Nonterminal, Production, CFG nonterminals = 'S VP NP PP P N Name V Det' (S, VP, NP, PP, P, N, Name, V, Det) = [Nonterminal(s) for s in nonterminals.split()] productions = ( # Syntactic Productions Production(S, [NP, VP]), Production(NP, [Det, N]), Production(NP, [NP, PP]), Production(VP, [VP, PP]), Production(VP, [V, NP, PP]), Production(VP, [V, NP]), Production(PP, [P, NP]), Production(PP, []), Production(PP, ['up', 'over', NP]), # Lexical Productions Production(NP, ['I']), Production(Det, ['the']), Production(Det, ['a']), Production(N, ['man']), Production(V, ['saw']), Production(P, ['in']), Production(P, ['with']), Production(N, ['park']), Production(N, ['dog']), Production(N, ['statue']), Production(Det, ['my']), ) grammar = CFG(S, productions) text = 'I saw a man in the park'.split() d=CFGDemo(grammar, text) d.mainloop() ###################################################################### # Old Demo ######################################################################
def demo(): from nltk import Nonterminal, CFG nonterminals = 'S VP NP PP P N Name V Det' (S, VP, NP, PP, P, N, Name, V, Det) = [Nonterminal(s) for s in nonterminals.split()] grammar = CFG.fromstring(""" S -> NP VP PP -> P NP NP -> Det N NP -> NP PP VP -> V NP VP -> VP PP Det -> 'a' Det -> 'the' Det -> 'my' NP -> 'I' N -> 'dog' N -> 'man' N -> 'park' N -> 'statue' V -> 'saw' P -> 'in' P -> 'up' P -> 'over' P -> 'with' """) def cb(grammar): print(grammar) top = Tk() editor = CFGEditor(top, grammar, cb) Label(top, text='\nTesting CFG Editor\n').pack() Button(top, text='Quit', command=top.destroy).pack() top.mainloop()
