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from transformers.tokenization_utils import AddedToken, PreTrainedTokenizer |
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from typing import List, Optional, Union |
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import os |
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MASK = "#" |
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MSA_PAD = "!" |
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UL_ALPHABET_PLUS = "ACDEFGHIKLMNPQRSTVWYBZXJOU-*#@!/[]{}" |
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MSA_AAS = "ACDEFGHIKLMNPQRSTVWYBZXJOU-" |
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GAP = "-" |
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START = "@" |
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STOP = "*" |
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SEP = "/" |
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END_AL = "]" |
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END_UL = "}" |
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START_AL = "[" |
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START_UL = "{" |
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class ProteinTokenizer(PreTrainedTokenizer): |
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def __init__( |
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self, |
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protein_alphabet: str = UL_ALPHABET_PLUS, |
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model_max_length: int = 2048, |
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pad_token=MSA_PAD, |
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mask_token=MASK, |
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all_aas=MSA_AAS, |
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gap_token=GAP, |
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bos_token=START, |
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eos_token=STOP, |
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sep_token=SEP, |
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**kwargs |
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): |
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"""Character tokenizer for Hugging Face transformers. |
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model_max_length (int): Model maximum sequence length. |
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""" |
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self.alphabet = list("".join(protein_alphabet)) |
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self.all_aas = list("".join(all_aas)) |
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self.a_to_i = {u: i for i, u in enumerate(self.alphabet)} |
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self.i_to_a = {i: u for i, u in enumerate(self.alphabet)} |
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self.gap_token = gap_token |
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bos_token = AddedToken(bos_token, lstrip=False, rstrip=False) if isinstance(bos_token, str) else bos_token |
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eos_token = AddedToken(eos_token, lstrip=False, rstrip=False) if isinstance(eos_token, str) else eos_token |
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sep_token = AddedToken(sep_token, lstrip=False, rstrip=False) if isinstance(sep_token, str) else sep_token |
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mask_token = AddedToken(mask_token, lstrip=False, rstrip=False) if isinstance(mask_token, str) else mask_token |
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pad_token = AddedToken(pad_token, lstrip=False, rstrip=False) if isinstance(pad_token, str) else pad_token |
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gap_token = AddedToken(gap_token, lstrip=False, rstrip=False) if isinstance(gap_token, str) else gap_token |
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super().__init__( |
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pad_token=pad_token, |
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mask_token=mask_token, |
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eos_token=eos_token, |
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bos_token=bos_token, |
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sep_token=sep_token, |
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model_max_length=model_max_length, |
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**kwargs |
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) |
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@property |
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def vocab_size(self): |
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return len(self.alphabet) |
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@property |
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def gap_token_id(self): |
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return self.convert_tokens_to_ids(self.gap_token) |
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def get_vocab(self): |
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return self.a_to_i |
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def _tokenize(self, text: str) -> List[str]: |
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return list(text) |
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def _convert_token_to_id(self, token) -> int: |
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return self.a_to_i[token] |
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def _convert_id_to_token(self, index) -> str: |
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return self.i_to_a[index] |
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def convert_tokens_to_string(self, tokens): |
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return "".join(tokens) |
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def build_inputs_with_special_tokens(self, token_ids_0, token_ids_1=None): |
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result = token_ids_0 |
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if token_ids_1 is not None: |
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raise NotImplementedError("This tokenizer does not support two sequences") |
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return result |
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def get_special_tokens_mask( |
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self, |
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token_ids_0: List[int], |
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token_ids_1: Optional[List[int]] = None, |
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already_has_special_tokens: bool = False, |
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) -> List[int]: |
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if already_has_special_tokens: |
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return super().get_special_tokens_mask( |
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token_ids_0=token_ids_0, |
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token_ids_1=token_ids_1, |
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already_has_special_tokens=True, |
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) |
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result = [0] * len(token_ids_0) |
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if token_ids_1 is not None: |
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raise NotImplementedError("This tokenizer does not support two sequences") |
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return result |
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def create_token_type_ids_from_sequences( |
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self, token_ids_0: List[int], token_ids_1: Optional[List[int]] = None |
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) -> List[int]: |
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""" |
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Identifies the type of token. 0 for the first sentence, 1 for the second sentence if it exists |
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""" |
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result = len(token_ids_0) * [0] |
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if token_ids_1 is not None: |
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raise NotImplementedError("This tokenizer does not support two sequences") |
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return result |
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def save_pretrained(self, save_directory: Union[str, os.PathLike], **kwargs): |
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super().save_pretrained(save_directory, **kwargs) |
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def save_vocabulary(self, save_directory: str, filename_prefix: Optional[str] = None): |
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return () |