File size: 25,404 Bytes
d916065
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
# Natural Language Toolkit: Verbnet Corpus Reader
#
# Copyright (C) 2001-2023 NLTK Project
# Author: Edward Loper <[email protected]>
# URL: <https://www.nltk.org/>
# For license information, see LICENSE.TXT

"""

An NLTK interface to the VerbNet verb lexicon



For details about VerbNet see:

https://verbs.colorado.edu/~mpalmer/projects/verbnet.html

"""

import re
import textwrap
from collections import defaultdict

from nltk.corpus.reader.xmldocs import XMLCorpusReader


class VerbnetCorpusReader(XMLCorpusReader):
    """

    An NLTK interface to the VerbNet verb lexicon.



    From the VerbNet site: "VerbNet (VN) (Kipper-Schuler 2006) is the largest

    on-line verb lexicon currently available for English. It is a hierarchical

    domain-independent, broad-coverage verb lexicon with mappings to other

    lexical resources such as WordNet (Miller, 1990; Fellbaum, 1998), XTAG

    (XTAG Research Group, 2001), and FrameNet (Baker et al., 1998)."



    For details about VerbNet see:

    https://verbs.colorado.edu/~mpalmer/projects/verbnet.html

    """

    # No unicode encoding param, since the data files are all XML.
    def __init__(self, root, fileids, wrap_etree=False):
        XMLCorpusReader.__init__(self, root, fileids, wrap_etree)

        self._lemma_to_class = defaultdict(list)
        """A dictionary mapping from verb lemma strings to lists of

        VerbNet class identifiers."""

        self._wordnet_to_class = defaultdict(list)
        """A dictionary mapping from wordnet identifier strings to

        lists of VerbNet class identifiers."""

        self._class_to_fileid = {}
        """A dictionary mapping from class identifiers to

        corresponding file identifiers.  The keys of this dictionary

        provide a complete list of all classes and subclasses."""

        self._shortid_to_longid = {}

        # Initialize the dictionaries.  Use the quick (regexp-based)
        # method instead of the slow (xml-based) method, because it
        # runs 2-30 times faster.
        self._quick_index()

    _LONGID_RE = re.compile(r"([^\-\.]*)-([\d+.\-]+)$")
    """Regular expression that matches (and decomposes) longids"""

    _SHORTID_RE = re.compile(r"[\d+.\-]+$")
    """Regular expression that matches shortids"""

    _INDEX_RE = re.compile(
        r'<MEMBER name="\??([^"]+)" wn="([^"]*)"[^>]+>|' r'<VNSUBCLASS ID="([^"]+)"/?>'
    )
    """Regular expression used by ``_index()`` to quickly scan the corpus

       for basic information."""

    def lemmas(self, vnclass=None):
        """

        Return a list of all verb lemmas that appear in any class, or

        in the ``classid`` if specified.

        """
        if vnclass is None:
            return sorted(self._lemma_to_class.keys())
        else:
            # [xx] should this include subclass members?
            if isinstance(vnclass, str):
                vnclass = self.vnclass(vnclass)
            return [member.get("name") for member in vnclass.findall("MEMBERS/MEMBER")]

    def wordnetids(self, vnclass=None):
        """

        Return a list of all wordnet identifiers that appear in any

        class, or in ``classid`` if specified.

        """
        if vnclass is None:
            return sorted(self._wordnet_to_class.keys())
        else:
            # [xx] should this include subclass members?
            if isinstance(vnclass, str):
                vnclass = self.vnclass(vnclass)
            return sum(
                (
                    member.get("wn", "").split()
                    for member in vnclass.findall("MEMBERS/MEMBER")
                ),
                [],
            )

    def classids(self, lemma=None, wordnetid=None, fileid=None, classid=None):
        """

        Return a list of the VerbNet class identifiers.  If a file

        identifier is specified, then return only the VerbNet class

        identifiers for classes (and subclasses) defined by that file.

        If a lemma is specified, then return only VerbNet class

        identifiers for classes that contain that lemma as a member.

        If a wordnetid is specified, then return only identifiers for

        classes that contain that wordnetid as a member.  If a classid

        is specified, then return only identifiers for subclasses of

        the specified VerbNet class.

        If nothing is specified, return all classids within VerbNet

        """
        if fileid is not None:
            return [c for (c, f) in self._class_to_fileid.items() if f == fileid]
        elif lemma is not None:
            return self._lemma_to_class[lemma]
        elif wordnetid is not None:
            return self._wordnet_to_class[wordnetid]
        elif classid is not None:
            xmltree = self.vnclass(classid)
            return [
                subclass.get("ID")
                for subclass in xmltree.findall("SUBCLASSES/VNSUBCLASS")
            ]
        else:
            return sorted(self._class_to_fileid.keys())

    def vnclass(self, fileid_or_classid):
        """Returns VerbNet class ElementTree



        Return an ElementTree containing the xml for the specified

        VerbNet class.



        :param fileid_or_classid: An identifier specifying which class

            should be returned.  Can be a file identifier (such as

            ``'put-9.1.xml'``), or a VerbNet class identifier (such as

            ``'put-9.1'``) or a short VerbNet class identifier (such as

            ``'9.1'``).

        """
        # File identifier: just return the xml.
        if fileid_or_classid in self._fileids:
            return self.xml(fileid_or_classid)

        # Class identifier: get the xml, and find the right elt.
        classid = self.longid(fileid_or_classid)
        if classid in self._class_to_fileid:
            fileid = self._class_to_fileid[self.longid(classid)]
            tree = self.xml(fileid)
            if classid == tree.get("ID"):
                return tree
            else:
                for subclass in tree.findall(".//VNSUBCLASS"):
                    if classid == subclass.get("ID"):
                        return subclass
                else:
                    assert False  # we saw it during _index()!

        else:
            raise ValueError(f"Unknown identifier {fileid_or_classid}")

    def fileids(self, vnclass_ids=None):
        """

        Return a list of fileids that make up this corpus.  If

        ``vnclass_ids`` is specified, then return the fileids that make

        up the specified VerbNet class(es).

        """
        if vnclass_ids is None:
            return self._fileids
        elif isinstance(vnclass_ids, str):
            return [self._class_to_fileid[self.longid(vnclass_ids)]]
        else:
            return [
                self._class_to_fileid[self.longid(vnclass_id)]
                for vnclass_id in vnclass_ids
            ]

    def frames(self, vnclass):
        """Given a VerbNet class, this method returns VerbNet frames



        The members returned are:

        1) Example

        2) Description

        3) Syntax

        4) Semantics



        :param vnclass: A VerbNet class identifier; or an ElementTree

            containing the xml contents of a VerbNet class.

        :return: frames - a list of frame dictionaries

        """
        if isinstance(vnclass, str):
            vnclass = self.vnclass(vnclass)
        frames = []
        vnframes = vnclass.findall("FRAMES/FRAME")
        for vnframe in vnframes:
            frames.append(
                {
                    "example": self._get_example_within_frame(vnframe),
                    "description": self._get_description_within_frame(vnframe),
                    "syntax": self._get_syntactic_list_within_frame(vnframe),
                    "semantics": self._get_semantics_within_frame(vnframe),
                }
            )
        return frames

    def subclasses(self, vnclass):
        """Returns subclass ids, if any exist



        Given a VerbNet class, this method returns subclass ids (if they exist)

        in a list of strings.



        :param vnclass: A VerbNet class identifier; or an ElementTree

            containing the xml contents of a VerbNet class.

        :return: list of subclasses

        """
        if isinstance(vnclass, str):
            vnclass = self.vnclass(vnclass)

        subclasses = [
            subclass.get("ID") for subclass in vnclass.findall("SUBCLASSES/VNSUBCLASS")
        ]
        return subclasses

    def themroles(self, vnclass):
        """Returns thematic roles participating in a VerbNet class



        Members returned as part of roles are-

        1) Type

        2) Modifiers



        :param vnclass: A VerbNet class identifier; or an ElementTree

            containing the xml contents of a VerbNet class.

        :return: themroles: A list of thematic roles in the VerbNet class

        """
        if isinstance(vnclass, str):
            vnclass = self.vnclass(vnclass)

        themroles = []
        for trole in vnclass.findall("THEMROLES/THEMROLE"):
            themroles.append(
                {
                    "type": trole.get("type"),
                    "modifiers": [
                        {"value": restr.get("Value"), "type": restr.get("type")}
                        for restr in trole.findall("SELRESTRS/SELRESTR")
                    ],
                }
            )
        return themroles

    ######################################################################
    # { Index Initialization
    ######################################################################

    def _index(self):
        """

        Initialize the indexes ``_lemma_to_class``,

        ``_wordnet_to_class``, and ``_class_to_fileid`` by scanning

        through the corpus fileids.  This is fast if ElementTree

        uses the C implementation (<0.1 secs), but quite slow (>10 secs)

        if only the python implementation is available.

        """
        for fileid in self._fileids:
            self._index_helper(self.xml(fileid), fileid)

    def _index_helper(self, xmltree, fileid):
        """Helper for ``_index()``"""
        vnclass = xmltree.get("ID")
        self._class_to_fileid[vnclass] = fileid
        self._shortid_to_longid[self.shortid(vnclass)] = vnclass
        for member in xmltree.findall("MEMBERS/MEMBER"):
            self._lemma_to_class[member.get("name")].append(vnclass)
            for wn in member.get("wn", "").split():
                self._wordnet_to_class[wn].append(vnclass)
        for subclass in xmltree.findall("SUBCLASSES/VNSUBCLASS"):
            self._index_helper(subclass, fileid)

    def _quick_index(self):
        """

        Initialize the indexes ``_lemma_to_class``,

        ``_wordnet_to_class``, and ``_class_to_fileid`` by scanning

        through the corpus fileids.  This doesn't do proper xml parsing,

        but is good enough to find everything in the standard VerbNet

        corpus -- and it runs about 30 times faster than xml parsing

        (with the python ElementTree; only 2-3 times faster

        if ElementTree uses the C implementation).

        """
        # nb: if we got rid of wordnet_to_class, this would run 2-3
        # times faster.
        for fileid in self._fileids:
            vnclass = fileid[:-4]  # strip the '.xml'
            self._class_to_fileid[vnclass] = fileid
            self._shortid_to_longid[self.shortid(vnclass)] = vnclass
            with self.open(fileid) as fp:
                for m in self._INDEX_RE.finditer(fp.read()):
                    groups = m.groups()
                    if groups[0] is not None:
                        self._lemma_to_class[groups[0]].append(vnclass)
                        for wn in groups[1].split():
                            self._wordnet_to_class[wn].append(vnclass)
                    elif groups[2] is not None:
                        self._class_to_fileid[groups[2]] = fileid
                        vnclass = groups[2]  # for <MEMBER> elts.
                        self._shortid_to_longid[self.shortid(vnclass)] = vnclass
                    else:
                        assert False, "unexpected match condition"

    ######################################################################
    # { Identifier conversion
    ######################################################################

    def longid(self, shortid):
        """Returns longid of a VerbNet class



        Given a short VerbNet class identifier (eg '37.10'), map it

        to a long id (eg 'confess-37.10').  If ``shortid`` is already a

        long id, then return it as-is"""
        if self._LONGID_RE.match(shortid):
            return shortid  # it's already a longid.
        elif not self._SHORTID_RE.match(shortid):
            raise ValueError("vnclass identifier %r not found" % shortid)
        try:
            return self._shortid_to_longid[shortid]
        except KeyError as e:
            raise ValueError("vnclass identifier %r not found" % shortid) from e

    def shortid(self, longid):
        """Returns shortid of a VerbNet class



        Given a long VerbNet class identifier (eg 'confess-37.10'),

        map it to a short id (eg '37.10').  If ``longid`` is already a

        short id, then return it as-is."""
        if self._SHORTID_RE.match(longid):
            return longid  # it's already a shortid.
        m = self._LONGID_RE.match(longid)
        if m:
            return m.group(2)
        else:
            raise ValueError("vnclass identifier %r not found" % longid)

    ######################################################################
    # { Frame access utility functions
    ######################################################################

    def _get_semantics_within_frame(self, vnframe):
        """Returns semantics within a single frame



        A utility function to retrieve semantics within a frame in VerbNet

        Members of the semantics dictionary:

        1) Predicate value

        2) Arguments



        :param vnframe: An ElementTree containing the xml contents of

            a VerbNet frame.

        :return: semantics: semantics dictionary

        """
        semantics_within_single_frame = []
        for pred in vnframe.findall("SEMANTICS/PRED"):
            arguments = [
                {"type": arg.get("type"), "value": arg.get("value")}
                for arg in pred.findall("ARGS/ARG")
            ]
            semantics_within_single_frame.append(
                {
                    "predicate_value": pred.get("value"),
                    "arguments": arguments,
                    "negated": pred.get("bool") == "!",
                }
            )
        return semantics_within_single_frame

    def _get_example_within_frame(self, vnframe):
        """Returns example within a frame



        A utility function to retrieve an example within a frame in VerbNet.



        :param vnframe: An ElementTree containing the xml contents of

            a VerbNet frame.

        :return: example_text: The example sentence for this particular frame

        """
        example_element = vnframe.find("EXAMPLES/EXAMPLE")
        if example_element is not None:
            example_text = example_element.text
        else:
            example_text = ""
        return example_text

    def _get_description_within_frame(self, vnframe):
        """Returns member description within frame



        A utility function to retrieve a description of participating members

        within a frame in VerbNet.



        :param vnframe: An ElementTree containing the xml contents of

            a VerbNet frame.

        :return: description: a description dictionary with members - primary and secondary

        """
        description_element = vnframe.find("DESCRIPTION")
        return {
            "primary": description_element.attrib["primary"],
            "secondary": description_element.get("secondary", ""),
        }

    def _get_syntactic_list_within_frame(self, vnframe):
        """Returns semantics within a frame



        A utility function to retrieve semantics within a frame in VerbNet.

        Members of the syntactic dictionary:

        1) POS Tag

        2) Modifiers



        :param vnframe: An ElementTree containing the xml contents of

            a VerbNet frame.

        :return: syntax_within_single_frame

        """
        syntax_within_single_frame = []
        for elt in vnframe.find("SYNTAX"):
            pos_tag = elt.tag
            modifiers = dict()
            modifiers["value"] = elt.get("value") if "value" in elt.attrib else ""
            modifiers["selrestrs"] = [
                {"value": restr.get("Value"), "type": restr.get("type")}
                for restr in elt.findall("SELRESTRS/SELRESTR")
            ]
            modifiers["synrestrs"] = [
                {"value": restr.get("Value"), "type": restr.get("type")}
                for restr in elt.findall("SYNRESTRS/SYNRESTR")
            ]
            syntax_within_single_frame.append(
                {"pos_tag": pos_tag, "modifiers": modifiers}
            )
        return syntax_within_single_frame

    ######################################################################
    # { Pretty Printing
    ######################################################################

    def pprint(self, vnclass):
        """Returns pretty printed version of a VerbNet class



        Return a string containing a pretty-printed representation of

        the given VerbNet class.



        :param vnclass: A VerbNet class identifier; or an ElementTree

            containing the xml contents of a VerbNet class.

        """
        if isinstance(vnclass, str):
            vnclass = self.vnclass(vnclass)

        s = vnclass.get("ID") + "\n"
        s += self.pprint_subclasses(vnclass, indent="  ") + "\n"
        s += self.pprint_members(vnclass, indent="  ") + "\n"
        s += "  Thematic roles:\n"
        s += self.pprint_themroles(vnclass, indent="    ") + "\n"
        s += "  Frames:\n"
        s += self.pprint_frames(vnclass, indent="    ")
        return s

    def pprint_subclasses(self, vnclass, indent=""):
        """Returns pretty printed version of subclasses of VerbNet class



        Return a string containing a pretty-printed representation of

        the given VerbNet class's subclasses.



        :param vnclass: A VerbNet class identifier; or an ElementTree

            containing the xml contents of a VerbNet class.

        """
        if isinstance(vnclass, str):
            vnclass = self.vnclass(vnclass)

        subclasses = self.subclasses(vnclass)
        if not subclasses:
            subclasses = ["(none)"]
        s = "Subclasses: " + " ".join(subclasses)
        return textwrap.fill(
            s, 70, initial_indent=indent, subsequent_indent=indent + "  "
        )

    def pprint_members(self, vnclass, indent=""):
        """Returns pretty printed version of members in a VerbNet class



        Return a string containing a pretty-printed representation of

        the given VerbNet class's member verbs.



        :param vnclass: A VerbNet class identifier; or an ElementTree

            containing the xml contents of a VerbNet class.

        """
        if isinstance(vnclass, str):
            vnclass = self.vnclass(vnclass)

        members = self.lemmas(vnclass)
        if not members:
            members = ["(none)"]
        s = "Members: " + " ".join(members)
        return textwrap.fill(
            s, 70, initial_indent=indent, subsequent_indent=indent + "  "
        )

    def pprint_themroles(self, vnclass, indent=""):
        """Returns pretty printed version of thematic roles in a VerbNet class



        Return a string containing a pretty-printed representation of

        the given VerbNet class's thematic roles.



        :param vnclass: A VerbNet class identifier; or an ElementTree

            containing the xml contents of a VerbNet class.

        """
        if isinstance(vnclass, str):
            vnclass = self.vnclass(vnclass)

        pieces = []
        for themrole in self.themroles(vnclass):
            piece = indent + "* " + themrole.get("type")
            modifiers = [
                modifier["value"] + modifier["type"]
                for modifier in themrole["modifiers"]
            ]
            if modifiers:
                piece += "[{}]".format(" ".join(modifiers))
            pieces.append(piece)
        return "\n".join(pieces)

    def pprint_frames(self, vnclass, indent=""):
        """Returns pretty version of all frames in a VerbNet class



        Return a string containing a pretty-printed representation of

        the list of frames within the VerbNet class.



        :param vnclass: A VerbNet class identifier; or an ElementTree

            containing the xml contents of a VerbNet class.

        """
        if isinstance(vnclass, str):
            vnclass = self.vnclass(vnclass)
        pieces = []
        for vnframe in self.frames(vnclass):
            pieces.append(self._pprint_single_frame(vnframe, indent))
        return "\n".join(pieces)

    def _pprint_single_frame(self, vnframe, indent=""):
        """Returns pretty printed version of a single frame in a VerbNet class



        Returns a string containing a pretty-printed representation of

        the given frame.



        :param vnframe: An ElementTree containing the xml contents of

            a VerbNet frame.

        """
        frame_string = self._pprint_description_within_frame(vnframe, indent) + "\n"
        frame_string += self._pprint_example_within_frame(vnframe, indent + " ") + "\n"
        frame_string += (
            self._pprint_syntax_within_frame(vnframe, indent + "  Syntax: ") + "\n"
        )
        frame_string += indent + "  Semantics:\n"
        frame_string += self._pprint_semantics_within_frame(vnframe, indent + "    ")
        return frame_string

    def _pprint_example_within_frame(self, vnframe, indent=""):
        """Returns pretty printed version of example within frame in a VerbNet class



        Return a string containing a pretty-printed representation of

        the given VerbNet frame example.



        :param vnframe: An ElementTree containing the xml contents of

            a Verbnet frame.

        """
        if vnframe["example"]:
            return indent + " Example: " + vnframe["example"]

    def _pprint_description_within_frame(self, vnframe, indent=""):
        """Returns pretty printed version of a VerbNet frame description



        Return a string containing a pretty-printed representation of

        the given VerbNet frame description.



        :param vnframe: An ElementTree containing the xml contents of

            a VerbNet frame.

        """
        description = indent + vnframe["description"]["primary"]
        if vnframe["description"]["secondary"]:
            description += " ({})".format(vnframe["description"]["secondary"])
        return description

    def _pprint_syntax_within_frame(self, vnframe, indent=""):
        """Returns pretty printed version of syntax within a frame in a VerbNet class



        Return a string containing a pretty-printed representation of

        the given VerbNet frame syntax.



        :param vnframe: An ElementTree containing the xml contents of

            a VerbNet frame.

        """
        pieces = []
        for element in vnframe["syntax"]:
            piece = element["pos_tag"]
            modifier_list = []
            if "value" in element["modifiers"] and element["modifiers"]["value"]:
                modifier_list.append(element["modifiers"]["value"])
            modifier_list += [
                "{}{}".format(restr["value"], restr["type"])
                for restr in (
                    element["modifiers"]["selrestrs"]
                    + element["modifiers"]["synrestrs"]
                )
            ]
            if modifier_list:
                piece += "[{}]".format(" ".join(modifier_list))
            pieces.append(piece)

        return indent + " ".join(pieces)

    def _pprint_semantics_within_frame(self, vnframe, indent=""):
        """Returns a pretty printed version of semantics within frame in a VerbNet class



        Return a string containing a pretty-printed representation of

        the given VerbNet frame semantics.



        :param vnframe: An ElementTree containing the xml contents of

            a VerbNet frame.

        """
        pieces = []
        for predicate in vnframe["semantics"]:
            arguments = [argument["value"] for argument in predicate["arguments"]]
            pieces.append(
                f"{'¬' if predicate['negated'] else ''}{predicate['predicate_value']}({', '.join(arguments)})"
            )
        return "\n".join(f"{indent}* {piece}" for piece in pieces)