cognitivess commited on
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Update cognitivess_model/tokenization_cognitivess.py

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cognitivess_model/tokenization_cognitivess.py CHANGED
@@ -1,48 +1,462 @@
1
- # cognitivess_model/tokenization_cognitivess.py
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2
 
3
- from transformers import PreTrainedTokenizer
4
- import json
5
 
6
  class CognitivessTokenizer(PreTrainedTokenizer):
7
- def __init__(self, vocab_file, merges_file=None, **kwargs):
8
- super().__init__(**kwargs)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
9
  self.vocab_file = vocab_file
10
- self.merges_file = merges_file
11
- self.load_vocab()
12
-
13
- def load_vocab(self):
14
- # Load vocabulary
15
- with open(self.vocab_file, 'r') as f:
16
- self.vocab = {line.strip(): idx for idx, line in enumerate(f)}
17
-
18
- # Load merges file if exists
19
- self.merges = []
20
- if self.merges_file:
21
- with open(self.merges_file, 'r') as f:
22
- self.merges = [line.strip() for line in f]
23
-
24
- def _tokenize(self, text):
25
- # Tokenization logic (basic example)
26
- tokens = text.split() # Simple whitespace-based tokenization
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
27
  return tokens
28
 
29
- def convert_tokens_to_ids(self, tokens):
30
- return [self.vocab.get(token, self.vocab.get('[UNK]')) for token in tokens]
31
-
32
- def convert_ids_to_tokens(self, ids):
33
- reverse_vocab = {idx: token for token, idx in self.vocab.items()}
34
- return [reverse_vocab.get(idx, '[UNK]') for idx in ids]
35
-
36
- def save_vocabulary(self, save_directory):
37
- vocab_path = f"{save_directory}/vocab.txt"
38
- with open(vocab_path, 'w') as f:
39
- for token in self.vocab:
40
- f.write(f"{token}\n")
41
-
42
- if self.merges_file:
43
- merges_path = f"{save_directory}/merges.txt"
44
- with open(merges_path, 'w') as f:
45
- for merge in self.merges:
46
- f.write(f"{merge}\n")
47
- return vocab_path, merges_path
48
- return vocab_path,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ # coding=utf-8
2
+ # Copyright 2022 Cognitivess and the HuggingFace Inc. team. All rights reserved.
3
+ #
4
+ # Licensed under the Apache License, Version 2.0 (the "License");
5
+ # you may not use this file except in compliance with the License.
6
+ # You may obtain a copy of the License at
7
+ #
8
+ # http://www.apache.org/licenses/LICENSE-2.0
9
+ #
10
+ # Unless required by applicable law or agreed to in writing, software
11
+ # distributed under the License is distributed on an "AS IS" BASIS,
12
+ # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13
+ # See the License for the specific language governing permissions and
14
+ # limitations under the License.
15
+
16
+ """Tokenization classes for Cognitivess."""
17
+
18
+ import os
19
+ from shutil import copyfile
20
+ from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple
21
+
22
+ import sentencepiece as spm
23
+
24
+ from ...convert_slow_tokenizer import import_protobuf
25
+ from ...tokenization_utils import AddedToken, PreTrainedTokenizer
26
+ from ...utils import logging
27
+
28
+
29
+ if TYPE_CHECKING:
30
+ from ...tokenization_utils_base import TextInput
31
+
32
+ logger = logging.get_logger(__name__)
33
+
34
+ VOCAB_FILES_NAMES = {"vocab_file": "tokenizer.model"}
35
+
36
+ SPIECE_UNDERLINE = "▁"
37
+
38
+ B_INST, E_INST = "[INST]", "[/INST]"
39
+ B_SYS, E_SYS = "<<SYS>>\n", "\n<</SYS>>\n\n"
40
+
41
+ # fmt: off
42
+ DEFAULT_SYSTEM_PROMPT = """You are a helpful, respectful and honest assistant. Always answer as helpfully as possible, while being safe. Your \
43
+ answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure\
44
+ that your responses are socially unbiased and positive in nature.
45
+
46
+ If a question does not make any sense, or is not factually coherent, explain why instead of answering something not \
47
+ correct. If you don't know the answer to a question, please don't share false information."""
48
+ # fmt: on
49
 
 
 
50
 
51
  class CognitivessTokenizer(PreTrainedTokenizer):
52
+ """
53
+ Construct a Cognitivess tokenizer. Based on byte-level Byte-Pair-Encoding. The default padding token is unset as there is
54
+ no padding token in the original model.
55
+
56
+ Args:
57
+ vocab_file (`str`):
58
+ Path to the vocabulary file.
59
+ unk_token (`str` or `tokenizers.AddedToken`, *optional*, defaults to `"<unk>"`):
60
+ The unknown token. A token that is not in the vocabulary cannot be converted to an ID and is set to be this
61
+ token instead.
62
+ bos_token (`str` or `tokenizers.AddedToken`, *optional*, defaults to `"<s>"`):
63
+ The beginning of sequence token that was used during pretraining. Can be used a sequence classifier token.
64
+ eos_token (`str` or `tokenizers.AddedToken`, *optional*, defaults to `"</s>"`):
65
+ The end of sequence token.
66
+ pad_token (`str` or `tokenizers.AddedToken`, *optional*):
67
+ A special token used to make arrays of tokens the same size for batching purpose. Will then be ignored by
68
+ attention mechanisms or loss computation.
69
+ sp_model_kwargs (`Dict[str, Any]`, `Optional`, *optional*):
70
+ Will be passed to the `SentencePieceProcessor.__init__()` method. The [Python wrapper for
71
+ SentencePiece](https://github.com/google/sentencepiece/tree/master/python) can be used, among other things,
72
+ to set:
73
+
74
+ - `enable_sampling`: Enable subword regularization.
75
+ - `nbest_size`: Sampling parameters for unigram. Invalid for BPE-Dropout.
76
+
77
+ - `nbest_size = {0,1}`: No sampling is performed.
78
+ - `nbest_size > 1`: samples from the nbest_size results.
79
+ - `nbest_size < 0`: assuming that nbest_size is infinite and samples from the all hypothesis (lattice)
80
+ using forward-filtering-and-backward-sampling algorithm.
81
+
82
+ - `alpha`: Smoothing parameter for unigram sampling, and dropout probability of merge operations for
83
+ BPE-dropout.
84
+
85
+ add_bos_token (`bool`, *optional*, defaults to `True`):
86
+ Whether or not to add an `bos_token` at the start of sequences.
87
+ add_eos_token (`bool`, *optional*, defaults to `False`):
88
+ Whether or not to add an `eos_token` at the end of sequences.
89
+ clean_up_tokenization_spaces (`bool`, *optional*, defaults to `False`):
90
+ Whether or not to cleanup spaces after decoding, cleanup consists in removing potential artifacts like
91
+ extra spaces.
92
+ use_default_system_prompt (`bool`, *optional*, defaults to `False`):
93
+ Whether or not the default system prompt for Cognitivess should be used.
94
+ spaces_between_special_tokens (`bool`, *optional*, defaults to `False`):
95
+ Whether or not to add spaces between special tokens.
96
+ legacy (`bool`, *optional*):
97
+ Whether or not the `legacy` behavior of the tokenizer should be used. Legacy is before the merge of #24622
98
+ and #25224 which includes fixes to properly handle tokens that appear after special tokens.
99
+ Make sure to also set `from_slow` to `True`.
100
+ A simple example:
101
+
102
+ - `legacy=True`:
103
+ ```python
104
+ >>> from transformers import CognitivessTokenizerFast
105
+
106
+ >>> tokenizer = CognitivessTokenizerFast.from_pretrained("CognitivessAI/cognitivess", legacy=True, from_slow=True)
107
+ >>> tokenizer.encode("Hello <s>.") # 869 is '▁.'
108
+ [1, 15043, 29871, 1, 869]
109
+ ```
110
+ - `legacy=False`:
111
+ ```python
112
+ >>> from transformers import CognitivessTokenizerFast
113
+
114
+ >>> tokenizer = CognitivessTokenizerFast.from_pretrained("CognitivessAI/cognitivess", legacy=False, from_slow=True)
115
+ >>> tokenizer.encode("Hello <s>.") # 29889 is '.'
116
+ [1, 15043, 29871, 1, 29889]
117
+ ```
118
+ Checkout the [pull request](https://github.com/huggingface/transformers/pull/24565) for more details.
119
+ add_prefix_space (`bool`, *optional*, defaults to `True`):
120
+ Whether or not to add an initial space to the input. This allows to treat the leading word just as any
121
+ other word. Again, this should be set with `from_slow=True` to make sure it's taken into account.
122
+ """
123
+
124
+ vocab_files_names = VOCAB_FILES_NAMES
125
+ model_input_names = ["input_ids", "attention_mask"]
126
+
127
+ def __init__(
128
+ self,
129
+ vocab_file,
130
+ unk_token="<unk>",
131
+ bos_token="<s>",
132
+ eos_token="</s>",
133
+ pad_token=None,
134
+ sp_model_kwargs: Optional[Dict[str, Any]] = None,
135
+ add_bos_token=True,
136
+ add_eos_token=False,
137
+ clean_up_tokenization_spaces=False,
138
+ use_default_system_prompt=False,
139
+ spaces_between_special_tokens=False,
140
+ legacy=None,
141
+ add_prefix_space=True,
142
+ **kwargs,
143
+ ):
144
+ self.sp_model_kwargs = {} if sp_model_kwargs is None else sp_model_kwargs
145
+ bos_token = AddedToken(bos_token, normalized=False, special=True) if isinstance(bos_token, str) else bos_token
146
+ eos_token = AddedToken(eos_token, normalized=False, special=True) if isinstance(eos_token, str) else eos_token
147
+ unk_token = AddedToken(unk_token, normalized=False, special=True) if isinstance(unk_token, str) else unk_token
148
+ pad_token = AddedToken(pad_token, normalized=False, special=True) if isinstance(pad_token, str) else pad_token
149
+
150
+ if legacy is None:
151
+ logger.warning_once(
152
+ f"You are using the default legacy behaviour of the {self.__class__}. This is"
153
+ " expected, and simply means that the `legacy` (previous) behavior will be used so nothing changes for you."
154
+ " If you want to use the new behaviour, set `legacy=False`. This should only be set if you understand what it"
155
+ " means, and thoroughly read the reason why this was added as explained in"
156
+ " https://github.com/huggingface/transformers/pull/24565 - if you loaded a Cognitivess tokenizer from a GGUF file"
157
+ " you can ignore this message"
158
+ )
159
+ legacy = True
160
+
161
+ self.legacy = legacy
162
  self.vocab_file = vocab_file
163
+ self.add_bos_token = add_bos_token
164
+ self.add_eos_token = add_eos_token
165
+ self.use_default_system_prompt = use_default_system_prompt
166
+ self.sp_model = self.get_spm_processor(kwargs.pop("from_slow", False))
167
+ self.add_prefix_space = add_prefix_space
168
+
169
+ super().__init__(
170
+ bos_token=bos_token,
171
+ eos_token=eos_token,
172
+ unk_token=unk_token,
173
+ pad_token=pad_token,
174
+ add_bos_token=add_bos_token,
175
+ add_eos_token=add_eos_token,
176
+ sp_model_kwargs=self.sp_model_kwargs,
177
+ clean_up_tokenization_spaces=clean_up_tokenization_spaces,
178
+ use_default_system_prompt=use_default_system_prompt,
179
+ spaces_between_special_tokens=spaces_between_special_tokens,
180
+ legacy=legacy,
181
+ add_prefix_space=add_prefix_space,
182
+ **kwargs,
183
+ )
184
+
185
+ @property
186
+ def unk_token_length(self):
187
+ return len(self.sp_model.encode(str(self.unk_token)))
188
+
189
+ # Copied from transformers.models.t5.tokenization_t5.T5Tokenizer.get_spm_processor
190
+ def get_spm_processor(self, from_slow=False):
191
+ tokenizer = spm.SentencePieceProcessor(**self.sp_model_kwargs)
192
+ if self.legacy or from_slow: # no dependency on protobuf
193
+ tokenizer.Load(self.vocab_file)
194
+ return tokenizer
195
+
196
+ with open(self.vocab_file, "rb") as f:
197
+ sp_model = f.read()
198
+ model_pb2 = import_protobuf(f"The new behaviour of {self.__class__.__name__} (with `self.legacy = False`)")
199
+ model = model_pb2.ModelProto.FromString(sp_model)
200
+ normalizer_spec = model_pb2.NormalizerSpec()
201
+ normalizer_spec.add_dummy_prefix = False
202
+ model.normalizer_spec.MergeFrom(normalizer_spec)
203
+ sp_model = model.SerializeToString()
204
+ tokenizer.LoadFromSerializedProto(sp_model)
205
+ return tokenizer
206
+
207
+ def __getstate__(self):
208
+ state = self.__dict__.copy()
209
+ state["sp_model"] = None
210
+ state["sp_model_proto"] = self.sp_model.serialized_model_proto()
211
+ return state
212
+
213
+ def __setstate__(self, d):
214
+ self.__dict__ = d
215
+ self.sp_model = spm.SentencePieceProcessor(**self.sp_model_kwargs)
216
+ self.sp_model.LoadFromSerializedProto(self.sp_model_proto)
217
+
218
+ @property
219
+ def vocab_size(self):
220
+ """Returns vocab size"""
221
+ return self.sp_model.get_piece_size()
222
+
223
+ def get_vocab(self):
224
+ """Returns vocab as a dict"""
225
+ vocab = {self.convert_ids_to_tokens(i): i for i in range(self.vocab_size)}
226
+ vocab.update(self.added_tokens_encoder)
227
+ return vocab
228
+
229
+ # Copied from transformers.models.t5.tokenization_t5.T5Tokenizer.tokenize
230
+ def tokenize(self, text: "TextInput", **kwargs) -> List[str]:
231
+ """
232
+ Converts a string to a list of tokens. If `self.legacy` is set to `False`, a prefix token is added unless the
233
+ first token is special.
234
+ """
235
+ if self.legacy or len(text) == 0:
236
+ return super().tokenize(text, **kwargs)
237
+
238
+ text = text.replace(SPIECE_UNDERLINE, " ")
239
+ if self.add_prefix_space:
240
+ text = SPIECE_UNDERLINE + text
241
+
242
+ tokens = super().tokenize(text, **kwargs)
243
+
244
+ if len(tokens) > 1 and tokens[0] == SPIECE_UNDERLINE and tokens[1] in self.all_special_tokens:
245
+ tokens = tokens[1:]
246
  return tokens
247
 
248
+ # Copied from transformers.models.t5.tokenization_t5.T5Tokenizer._tokenize
249
+ def _tokenize(self, text, **kwargs):
250
+ """
251
+ Returns a tokenized string.
252
+
253
+ We de-activated the `add_dummy_prefix` option, thus the sentencepiece internals will always strip any
254
+ SPIECE_UNDERLINE. For example: `self.sp_model.encode(f"{SPIECE_UNDERLINE}Hey", out_type = str)` will give
255
+ `['H', 'e', 'y']` instead of `['▁He', 'y']`. Thus we always encode `f"{unk_token}text"` and strip the
256
+ `unk_token`. Here is an example with `unk_token = "<unk>"` and `unk_token_length = 4`.
257
+ `self.tokenizer.sp_model.encode("<unk> Hey", out_type = str)[4:]`.
258
+ """
259
+ tokens = self.sp_model.encode(text, out_type=str)
260
+ if self.legacy or not text.startswith((SPIECE_UNDERLINE, " ")):
261
+ return tokens
262
+
263
+ # 1. Encode string + prefix ex: "<unk> Hey"
264
+ tokens = self.sp_model.encode(self.unk_token + text, out_type=str)
265
+ # 2. Remove self.unk_token from ['<','unk','>', '▁Hey']
266
+ return tokens[self.unk_token_length :] if len(tokens) >= self.unk_token_length else tokens
267
+
268
+ def _convert_token_to_id(self, token):
269
+ """Converts a token (str) in an id using the vocab."""
270
+ return self.sp_model.piece_to_id(token)
271
+
272
+ def _convert_id_to_token(self, index):
273
+ """Converts an index (integer) in a token (str) using the vocab."""
274
+ token = self.sp_model.IdToPiece(index)
275
+ return token
276
+
277
+ def convert_tokens_to_string(self, tokens):
278
+ """Converts a sequence of tokens (string) in a single string."""
279
+ # since we manually add the prefix space, we have to remove it when decoding
280
+ if tokens[0].startswith(SPIECE_UNDERLINE) and self.add_prefix_space:
281
+ tokens[0] = tokens[0][1:]
282
+
283
+ current_sub_tokens = []
284
+ out_string = ""
285
+ prev_is_special = False
286
+ for i, token in enumerate(tokens):
287
+ # make sure that special tokens are not decoded using sentencepiece model
288
+ if token in self.all_special_tokens:
289
+ if not prev_is_special and i != 0 and self.legacy:
290
+ out_string += " "
291
+ out_string += self.sp_model.decode(current_sub_tokens) + token
292
+ prev_is_special = True
293
+ current_sub_tokens = []
294
+ else:
295
+ if prev_is_special and i == 1 and self.add_prefix_space and not token.startswith(SPIECE_UNDERLINE):
296
+ out_string += " "
297
+ current_sub_tokens.append(token)
298
+ prev_is_special = False
299
+ out_string += self.sp_model.decode(current_sub_tokens)
300
+ return out_string
301
+
302
+ def save_vocabulary(self, save_directory, filename_prefix: Optional[str] = None) -> Tuple[str]:
303
+ """
304
+ Save the vocabulary and special tokens file to a directory.
305
+
306
+ Args:
307
+ save_directory (`str`):
308
+ The directory in which to save the vocabulary.
309
+
310
+ Returns:
311
+ `Tuple(str)`: Paths to the files saved.
312
+ """
313
+ if not os.path.isdir(save_directory):
314
+ logger.error(f"Vocabulary path ({save_directory}) should be a directory")
315
+ return
316
+ out_vocab_file = os.path.join(
317
+ save_directory, (filename_prefix + "-" if filename_prefix else "") + VOCAB_FILES_NAMES["vocab_file"]
318
+ )
319
+
320
+ if os.path.abspath(self.vocab_file) != os.path.abspath(out_vocab_file) and os.path.isfile(self.vocab_file):
321
+ copyfile(self.vocab_file, out_vocab_file)
322
+ elif not os.path.isfile(self.vocab_file):
323
+ with open(out_vocab_file, "wb") as fi:
324
+ content_spiece_model = self.sp_model.serialized_model_proto()
325
+ fi.write(content_spiece_model)
326
+
327
+ return (out_vocab_file,)
328
+
329
+ def build_inputs_with_special_tokens(self, token_ids_0, token_ids_1=None):
330
+ bos_token_id = [self.bos_token_id] if self.add_bos_token else []
331
+ eos_token_id = [self.eos_token_id] if self.add_eos_token else []
332
+
333
+ output = bos_token_id + token_ids_0 + eos_token_id
334
+
335
+ if token_ids_1 is not None:
336
+ output = output + bos_token_id + token_ids_1 + eos_token_id
337
+
338
+ return output
339
+
340
+ def get_special_tokens_mask(
341
+ self, token_ids_0: List[int], token_ids_1: Optional[List[int]] = None, already_has_special_tokens: bool = False
342
+ ) -> List[int]:
343
+ """
344
+ Retrieve sequence ids from a token list that has no special tokens added. This method is called when adding
345
+ special tokens using the tokenizer `prepare_for_model` method.
346
+
347
+ Args:
348
+ token_ids_0 (`List[int]`):
349
+ List of IDs.
350
+ token_ids_1 (`List[int]`, *optional*):
351
+ Optional second list of IDs for sequence pairs.
352
+ already_has_special_tokens (`bool`, *optional*, defaults to `False`):
353
+ Whether or not the token list is already formatted with special tokens for the model.
354
+
355
+ Returns:
356
+ `List[int]`: A list of integers in the range [0, 1]: 1 for a special token, 0 for a sequence token.
357
+ """
358
+ if already_has_special_tokens:
359
+ return super().get_special_tokens_mask(
360
+ token_ids_0=token_ids_0, token_ids_1=token_ids_1, already_has_special_tokens=True
361
+ )
362
+
363
+ bos_token_id = [1] if self.add_bos_token else []
364
+ eos_token_id = [1] if self.add_eos_token else []
365
+
366
+ if token_ids_1 is None:
367
+ return bos_token_id + ([0] * len(token_ids_0)) + eos_token_id
368
+ return (
369
+ bos_token_id
370
+ + ([0] * len(token_ids_0))
371
+ + eos_token_id
372
+ + bos_token_id
373
+ + ([0] * len(token_ids_1))
374
+ + eos_token_id
375
+ )
376
+
377
+ def create_token_type_ids_from_sequences(
378
+ self, token_ids_0: List[int], token_ids_1: Optional[List[int]] = None
379
+ ) -> List[int]:
380
+ """
381
+ Creates a mask from the two sequences passed to be used in a sequence-pair classification task. An ALBERT
382
+ sequence pair mask has the following format:
383
+
384
+ ```
385
+ 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1
386
+ | first sequence | second sequence |
387
+ ```
388
+
389
+ if token_ids_1 is None, only returns the first portion of the mask (0s).
390
+
391
+ Args:
392
+ token_ids_0 (`List[int]`):
393
+ List of ids.
394
+ token_ids_1 (`List[int]`, *optional*):
395
+ Optional second list of IDs for sequence pairs.
396
+
397
+ Returns:
398
+ `List[int]`: List of [token type IDs](../glossary#token-type-ids) according to the given sequence(s).
399
+ """
400
+ bos_token_id = [self.bos_token_id] if self.add_bos_token else []
401
+ eos_token_id = [self.eos_token_id] if self.add_eos_token else []
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+
403
+ output = [0] * len(bos_token_id + token_ids_0 + eos_token_id)
404
+
405
+ if token_ids_1 is not None:
406
+ output += [1] * len(bos_token_id + token_ids_1 + eos_token_id)
407
+
408
+ return output
409
+
410
+ @property
411
+ def default_chat_template(self):
412
+ """
413
+ Cognitivess uses [INST] and [/INST] to indicate user messages, and <<SYS>> and <</SYS>> to indicate system messages.
414
+ Assistant messages do not have special tokens, because Cognitivess chat models are generally trained with strict
415
+ user/assistant/user/assistant message ordering, and so assistant messages can be identified from the ordering
416
+ rather than needing special tokens. The system message is partly 'embedded' in the first user message, which
417
+ results in an unusual token ordering when it is present. This template should definitely be changed if you wish
418
+ to fine-tune a model with more flexible role ordering!
419
+
420
+ The output should look something like:
421
+
422
+ <bos>[INST] B_SYS SystemPrompt E_SYS Prompt [/INST] Answer <eos><bos>[INST] Prompt [/INST] Answer <eos>
423
+ <bos>[INST] Prompt [/INST]
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+
425
+ The reference for this chat template is [this code
426
+ snippet](https://github.com/facebookresearch/Cognitivess/blob/556949fdfb72da27c2f4a40b7f0e4cf0b8153a28/Cognitivess/generation.py#L320-L362)
427
+ in the original repository.
428
+ """
429
+ template = (
430
+ "{% if messages[0]['role'] == 'system' %}"
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+ "{% set loop_messages = messages[1:] %}" # Extract system message if it's present
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+ "{% set system_message = messages[0]['content'] %}"
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+ "{% elif USE_DEFAULT_PROMPT == true and not '<<SYS>>' in messages[0]['content'] %}"
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+ "{% set loop_messages = messages %}" # Or use the default system message if the flag is set
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+ "{% set system_message = 'DEFAULT_SYSTEM_MESSAGE' %}"
436
+ "{% else %}"
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+ "{% set loop_messages = messages %}"
438
+ "{% set system_message = false %}"
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+ "{% endif %}"
440
+ "{% for message in loop_messages %}" # Loop over all non-system messages
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+ "{% if (message['role'] == 'user') != (loop.index0 % 2 == 0) %}"
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+ "{{ raise_exception('Conversation roles must alternate user/assistant/user/assistant/...') }}"
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+ "{% endif %}"
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+ "{% if loop.index0 == 0 and system_message != false %}" # Embed system message in first message
445
+ "{% set content = '<<SYS>>\\n' + system_message + '\\n<</SYS>>\\n\\n' + message['content'] %}"
446
+ "{% else %}"
447
+ "{% set content = message['content'] %}"
448
+ "{% endif %}"
449
+ "{% if message['role'] == 'user' %}" # After all of that, handle messages/roles in a fairly normal way
450
+ "{{ bos_token + '[INST] ' + content.strip() + ' [/INST]' }}"
451
+ "{% elif message['role'] == 'system' %}"
452
+ "{{ '<<SYS>>\\n' + content.strip() + '\\n<</SYS>>\\n\\n' }}"
453
+ "{% elif message['role'] == 'assistant' %}"
454
+ "{{ ' ' + content.strip() + ' ' + eos_token }}"
455
+ "{% endif %}"
456
+ "{% endfor %}"
457
+ )
458
+ template = template.replace("USE_DEFAULT_PROMPT", "true" if self.use_default_system_prompt else "false")
459
+ default_message = DEFAULT_SYSTEM_PROMPT.replace("\n", "\\n").replace("'", "\\'")
460
+ template = template.replace("DEFAULT_SYSTEM_MESSAGE", default_message)
461
+
462
+ return template