ChemQ3MTP-base / FastChemTokenizerHF.py
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import torch
import json
import os
from typing import List, Union, Optional, Tuple, Dict, Any
from functools import lru_cache
from collections.abc import Mapping
# ------------------------------
# BatchEncoding
# ------------------------------
class BatchEncoding(dict, Mapping):
"""Minimal BatchEncoding compatible wrapper."""
def __init__(self, data: dict, tensor_type: Optional[str] = None):
data = {} if data is None else {k: v for k, v in data.items()}
super().__init__(data)
self.data = data
self.tensor_type = tensor_type
for k, v in data.items():
setattr(self, k, v)
def __getitem__(self, key): return self.data[key]
def __iter__(self): return iter(self.data)
def __len__(self): return len(self.data)
def keys(self): return self.data.keys()
def values(self): return self.data.values()
def items(self): return self.data.items()
def get(self, key, default=None): return self.data.get(key, default)
def to(self, device):
if self.tensor_type in ("pt", "torch"):
for k, v in list(self.data.items()):
if torch.is_tensor(v):
self.data[k] = v.to(device)
setattr(self, k, self.data[k])
return self
def cpu(self): return self.to("cpu")
def cuda(self): return self.to("cuda")
def detach(self):
if self.tensor_type in ("pt", "torch"):
for k, v in list(self.data.items()):
if torch.is_tensor(v):
self.data[k] = v.detach()
setattr(self, k, self.data[k])
return self
def __repr__(self):
keys = ", ".join(list(self.data.keys())[:10])
return f"BatchEncoding(keys=[{keys}], tensor_type={self.tensor_type})"
# ------------------------------
# Base class
# ------------------------------
class PreTrainedTokenizerBase:
def __init__(self, **kwargs):
for key, value in kwargs.items():
if key.endswith('_token'):
setattr(self, f"_{key}", value)
setattr(self, f"{key}_id", None)
self.model_max_length = kwargs.get('model_max_length', 512)
self.padding_side = kwargs.get('padding_side', 'right')
self.truncation_side = kwargs.get('truncation_side', 'right')
self.chat_template = kwargs.get('chat_template')
# ------------------------------
# Trie node
# ------------------------------
class TrieNode:
__slots__ = ['children', 'token_id']
def __init__(self):
self.children = {}
self.token_id = None
# ------------------------------
# FastChemTokenizer
# ------------------------------
class FastChemTokenizer(PreTrainedTokenizerBase):
def __init__(self, token_to_id=None, vocab_file=None, **kwargs):
if vocab_file is not None:
with open(vocab_file, "r", encoding="utf-8") as f:
token_to_id = json.load(f)
token_to_id = {str(k): int(v) for k, v in token_to_id.items()}
self.token_to_id = token_to_id
self.id_to_token = {v: k for k, v in token_to_id.items()}
# Build trie
self.trie_root = self._build_trie(self.token_to_id)
# ✅ Call parent (sets token *strings*, may reset *_id to None)
super().__init__(
bos_token="<s>",
eos_token="</s>",
unk_token="<unk>",
pad_token="<pad>",
mask_token="<mask>",
model_max_length=kwargs.get("model_max_length", 512),
padding_side=kwargs.get("padding_side", "right"),
truncation_side=kwargs.get("truncation_side", "right"),
**kwargs,
)
# ✅ Re-map token strings → IDs from vocab
self.bos_token_id = self.token_to_id.get("<s>", 0)
self.eos_token_id = self.token_to_id.get("</s>", 1)
self.pad_token_id = self.token_to_id.get("<pad>", 2)
self.unk_token_id = self.token_to_id.get("<unk>", 3)
self.mask_token_id = self.token_to_id.get("<mask>", 4)
# Ensure reverse mapping always valid
self.id_to_token[self.bos_token_id] = "<s>"
self.id_to_token[self.eos_token_id] = "</s>"
self.id_to_token[self.pad_token_id] = "<pad>"
self.id_to_token[self.unk_token_id] = "<unk>"
self.id_to_token[self.mask_token_id] = "<mask>"
# Debug
print("✅ Special tokens bound:",
self.bos_token_id, self.eos_token_id, self.pad_token_id,
self.unk_token_id, self.mask_token_id)
# ✅ Ensure token *strings* also exist (for decode fallback)
self.bos_token = "<s>"
self.eos_token = "</s>"
self.pad_token = "<pad>"
self.unk_token = "<unk>"
self.mask_token = "<mask>"
def _build_trie(self, token_to_id):
root = TrieNode()
for token, tid in token_to_id.items():
node = root
for char in token:
if char not in node.children:
node.children[char] = TrieNode()
node = node.children[char]
node.token_id = tid
return root
@property
def vocab_size(self): return len(self.token_to_id)
def __len__(self): return len(self.token_to_id)
def get_vocab(self) -> Dict[str, int]: return self.token_to_id.copy()
@lru_cache(maxsize=10000)
def _cached_encode_str(self, s: str) -> Tuple[int, ...]:
return tuple(self._encode_core(s))
def _encode_core(self, text: str) -> List[int]:
tokens, result_ids = text, []
i, n = 0, len(tokens)
while i < n:
node, j = self.trie_root, i
last_match_id, last_match_end = None, i
while j < n and tokens[j] in node.children:
node = node.children[tokens[j]]
j += 1
if node.token_id is not None:
last_match_id, last_match_end = node.token_id, j
if last_match_id is not None:
result_ids.append(last_match_id)
i = last_match_end
else:
tid = self.token_to_id.get(tokens[i], self.unk_token_id)
result_ids.append(tid)
i += 1
return result_ids
# ------------------------------
# Converters
# ------------------------------
def _convert_token_to_id(self, token: str) -> int:
return self.token_to_id.get(token, self.unk_token_id)
def _convert_id_to_token(self, index: int) -> str:
return self.id_to_token.get(index, self.unk_token)
def convert_tokens_to_ids(self, tokens: Union[str, List[str]]):
if isinstance(tokens, str): return self._convert_token_to_id(tokens)
return [self._convert_token_to_id(tok) for tok in tokens]
def convert_ids_to_tokens(self, ids: Union[int, List[int]]):
if isinstance(ids, int): return self._convert_id_to_token(ids)
return [self._convert_id_to_token(i) for i in ids]
def convert_tokens_to_string(self, tokens: List[str]) -> str: return "".join(tokens)
# ------------------------------
# Encoding / Decoding
# ------------------------------
# ------------------------------
# Convenience wrappers
# ------------------------------
def encode(
self,
text: str,
text_pair: Optional[str] = None,
add_special_tokens: bool = True,
padding: bool = False,
truncation: bool = False,
max_length: Optional[int] = None,
return_tensors: Optional[str] = None,
) -> List[int]:
encoded = self.encode_plus(
text=text,
text_pair=text_pair,
add_special_tokens=add_special_tokens,
padding=padding,
truncation=truncation,
max_length=max_length,
return_tensors=return_tensors,
)
input_ids = encoded["input_ids"]
if isinstance(input_ids, torch.Tensor):
if input_ids.dim() > 1:
input_ids = input_ids.squeeze(0)
input_ids = input_ids.tolist()
return input_ids
def __call__(
self,
text: Union[str, List[str]],
text_pair: Optional[Union[str, List[str]]] = None,
add_special_tokens: bool = True,
padding: Union[bool, str] = False,
truncation: Union[bool, str] = False,
max_length: Optional[int] = None,
stride: int = 0,
is_split_into_words: bool = False,
pad_to_multiple_of: Optional[int] = None,
return_tensors: Optional[Union[str, Any]] = None,
return_token_type_ids: Optional[bool] = None,
return_attention_mask: Optional[bool] = None,
return_overflowing_tokens: bool = False,
return_special_tokens_mask: bool = False,
return_offsets_mapping: bool = False,
return_length: bool = False,
verbose: bool = True,
**kwargs
) -> BatchEncoding:
"""HuggingFace-compatible: one string → encode_plus, list → batch_encode_plus"""
if return_token_type_ids is None:
return_token_type_ids = True
if return_attention_mask is None:
return_attention_mask = True
if isinstance(text, list):
if text_pair is not None:
batch = [(t, p) for t, p in zip(text, text_pair)]
else:
batch = text
return self.batch_encode_plus(
batch,
add_special_tokens=add_special_tokens,
padding=padding,
truncation=truncation,
max_length=max_length,
stride=stride,
is_split_into_words=is_split_into_words,
pad_to_multiple_of=pad_to_multiple_of,
return_tensors=return_tensors,
return_token_type_ids=return_token_type_ids,
return_attention_mask=return_attention_mask,
return_overflowing_tokens=return_overflowing_tokens,
return_special_tokens_mask=return_special_tokens_mask,
return_offsets_mapping=return_offsets_mapping,
return_length=return_length,
verbose=verbose,
**kwargs
)
else:
return self.encode_plus(
text=text,
text_pair=text_pair,
add_special_tokens=add_special_tokens,
padding=padding,
truncation=truncation,
max_length=max_length,
stride=stride,
is_split_into_words=is_split_into_words,
pad_to_multiple_of=pad_to_multiple_of,
return_tensors=return_tensors,
return_token_type_ids=return_token_type_ids,
return_attention_mask=return_attention_mask,
return_overflowing_tokens=return_overflowing_tokens,
return_special_tokens_mask=return_special_tokens_mask,
return_offsets_mapping=return_offsets_mapping,
return_length=return_length,
verbose=verbose,
**kwargs
)
def encode_plus(
self,
text: str,
text_pair: Optional[str] = None,
add_special_tokens: bool = True,
padding: Union[bool, str] = False,
truncation: Union[bool, str] = False,
max_length: Optional[int] = None,
stride: int = 0,
is_split_into_words: bool = False,
pad_to_multiple_of: Optional[int] = None,
return_tensors: Optional[Union[str, Any]] = None,
return_token_type_ids: Optional[bool] = True,
return_attention_mask: Optional[bool] = True,
return_overflowing_tokens: bool = False,
return_special_tokens_mask: bool = False,
return_offsets_mapping: bool = False,
return_length: bool = False,
verbose: bool = True,
**kwargs
) -> BatchEncoding:
if max_length is None: max_length = self.model_max_length
ids_a = list(self._cached_encode_str(text.strip()))
ids_b = list(self._cached_encode_str(text_pair.strip())) if text_pair else None
input_ids, token_type_ids = [], []
if add_special_tokens:
input_ids.append(self.bos_token_id); token_type_ids.append(0)
input_ids.extend(ids_a); token_type_ids.extend([0] * len(ids_a))
input_ids.append(self.eos_token_id); token_type_ids.append(0)
if ids_b is not None:
input_ids.extend(ids_b); token_type_ids.extend([1] * len(ids_b))
input_ids.append(self.eos_token_id); token_type_ids.append(1)
else:
input_ids = ids_a.copy(); token_type_ids = [0] * len(input_ids)
if ids_b is not None:
input_ids.extend(ids_b); token_type_ids.extend([1] * len(ids_b))
if truncation and len(input_ids) > max_length:
input_ids, token_type_ids = input_ids[:max_length], token_type_ids[:max_length]
encoded_dict = {"input_ids": input_ids}
if return_attention_mask:
if padding == True or padding == "max_length":
pad_len = max_length - len(input_ids)
if pad_len > 0:
if self.padding_side == "right":
input_ids.extend([self.pad_token_id] * pad_len)
token_type_ids.extend([0] * pad_len)
else:
input_ids = [self.pad_token_id] * pad_len + input_ids
token_type_ids = [0] * pad_len + token_type_ids
attention_mask = [0 if tid == self.pad_token_id else 1 for tid in input_ids]
encoded_dict["attention_mask"] = attention_mask
if return_token_type_ids: encoded_dict["token_type_ids"] = token_type_ids
if return_special_tokens_mask:
encoded_dict["special_tokens_mask"] = [
1 if tid in {self.bos_token_id, self.eos_token_id, self.pad_token_id, self.mask_token_id} else 0
for tid in input_ids
]
if return_length:
encoded_dict["length"] = len([tid for tid in input_ids if tid != self.pad_token_id])
if return_tensors in ["pt", "torch"]:
out = {}
for k, v in encoded_dict.items():
if isinstance(v, list):
tensor = torch.tensor(
[self.unk_token_id if x is None else int(x) for x in v], dtype=torch.long
).unsqueeze(0)
out[k] = tensor
else:
out[k] = v
return BatchEncoding(out, tensor_type=return_tensors)
return BatchEncoding(encoded_dict, tensor_type=None)
def batch_encode_plus(
self,
batch_text_or_text_pairs: List[Union[str, Tuple[str, str]]],
add_special_tokens: bool = True,
padding: Union[bool, str] = False,
truncation: Union[bool, str] = False,
max_length: Optional[int] = None,
stride: int = 0,
is_split_into_words: bool = False,
pad_to_multiple_of: Optional[int] = None,
return_tensors: Optional[Union[str, Any]] = None,
return_token_type_ids: Optional[bool] = True,
return_attention_mask: Optional[bool] = True,
return_overflowing_tokens: bool = False,
return_special_tokens_mask: bool = False,
return_offsets_mapping: bool = False,
return_length: bool = False,
verbose: bool = True,
**kwargs
) -> BatchEncoding:
if padding is True: padding = "longest"
if padding == "max_length" and max_length is None: max_length = self.model_max_length
all_input_ids, all_token_type_ids, all_attention_masks = [], [], []
all_special_masks, all_lengths = [], []
for item in batch_text_or_text_pairs:
t, tp = item if isinstance(item, tuple) else (item, None)
enc = self.encode_plus(
text=t, text_pair=tp, add_special_tokens=add_special_tokens,
padding=False, truncation=truncation, max_length=max_length,
return_tensors=None, return_token_type_ids=return_token_type_ids,
return_attention_mask=return_attention_mask,
return_special_tokens_mask=return_special_tokens_mask,
return_length=return_length, **kwargs
)
ids, tt, am = enc["input_ids"], enc.get("token_type_ids", [0]*len(enc["input_ids"])), enc.get("attention_mask",[1]*len(enc["input_ids"]))
sm, ln = enc.get("special_tokens_mask",[0]*len(ids)), enc.get("length", len([x for x in ids if x != self.pad_token_id]))
all_input_ids.append(ids); all_token_type_ids.append(tt); all_attention_masks.append(am)
all_special_masks.append(sm); all_lengths.append(ln)
pad_to = max(len(x) for x in all_input_ids) if padding == "longest" else (max_length if padding == "max_length" else None)
batched = {
"input_ids": all_input_ids,
"token_type_ids": all_token_type_ids if return_token_type_ids else None,
"attention_mask": all_attention_masks if return_attention_mask else None,
"special_tokens_mask": all_special_masks if return_special_tokens_mask else None,
"length": all_lengths if return_length else None,
}
if pad_to is not None:
for key in ["input_ids","token_type_ids","attention_mask","special_tokens_mask"]:
if batched.get(key) is None: continue
padded = []
for seq in batched[key]:
pad_len = pad_to - len(seq)
pad_val = self.pad_token_id if key=="input_ids" else 0
if pad_len > 0:
seq = seq+[pad_val]*pad_len if self.padding_side=="right" else [pad_val]*pad_len+seq
padded.append(seq)
batched[key] = padded
if return_tensors in ["pt", "torch"]:
def to_tensor(lst, pad_val=0):
return torch.tensor([[self.unk_token_id if x is None else int(x) for x in row] for row in lst], dtype=torch.long)
out = {}
if batched.get("input_ids") is not None: out["input_ids"] = to_tensor(batched["input_ids"], self.pad_token_id)
if batched.get("attention_mask") is not None: out["attention_mask"] = to_tensor(batched["attention_mask"],0)
if batched.get("token_type_ids") is not None: out["token_type_ids"] = to_tensor(batched["token_type_ids"],0)
if batched.get("special_tokens_mask") is not None: out["special_tokens_mask"] = to_tensor(batched["special_tokens_mask"],0)
if return_length and batched.get("length") is not None: out["length"] = torch.tensor([int(x) for x in batched["length"]], dtype=torch.long)
return BatchEncoding(out, tensor_type=return_tensors)
return BatchEncoding({k:v for k,v in batched.items() if v is not None}, tensor_type=None)
# ------------------------------
# Decoding
# ------------------------------
def decode(self, token_ids, skip_special_tokens=False, **kwargs):
if isinstance(token_ids, torch.Tensor): token_ids = token_ids.tolist()
special_ids = {self.bos_token_id,self.eos_token_id,self.pad_token_id,self.mask_token_id} if skip_special_tokens else set()
tokens = [self.id_to_token.get(tid,self.unk_token) for tid in token_ids if tid not in special_ids]
return "".join(tokens)
def batch_decode(self, sequences, skip_special_tokens=False, **kwargs):
if isinstance(sequences, torch.Tensor): sequences = sequences.tolist()
return [self.decode(seq, skip_special_tokens=skip_special_tokens, **kwargs) for seq in sequences]
def decode_with_trace(self, token_ids: List[int]):
print(f"\n🔍 Decoding {len(token_ids)} tokens:")
for i, tid in enumerate(token_ids):
token = self.id_to_token.get(tid, self.unk_token)
tid_str = "None" if tid is None else f"{tid:5d}"
print(f" [{i:03d}] ID={tid_str} → '{token}'")
def pad(
self,
encoded_inputs,
padding=True,
max_length=None,
pad_to_multiple_of=None,
return_tensors=None,
**kwargs,
):
"""
HuggingFace-style pad. Takes a list/dict of encoded inputs and pads them.
"""
if isinstance(encoded_inputs, dict):
encoded_inputs = [encoded_inputs]
input_ids = [ei["input_ids"] for ei in encoded_inputs]
attn_masks = [ei.get("attention_mask", [1]*len(ei["input_ids"])) for ei in encoded_inputs]
# determine pad length
max_len = max(len(ids) for ids in input_ids)
if pad_to_multiple_of:
max_len = ((max_len + pad_to_multiple_of - 1) // pad_to_multiple_of) * pad_to_multiple_of
if max_length is not None:
max_len = min(max_len, max_length)
padded_ids, padded_masks = [], []
for ids, mask in zip(input_ids, attn_masks):
pad_len = max_len - len(ids)
if self.padding_side == "right":
padded_ids.append(ids + [self.pad_token_id] * pad_len)
padded_masks.append(mask + [0] * pad_len)
else:
padded_ids.append([self.pad_token_id] * pad_len + ids)
padded_masks.append([0] * pad_len + mask)
out = {"input_ids": padded_ids, "attention_mask": padded_masks}
if return_tensors in ["pt", "torch"]:
out = {k: torch.tensor(v, dtype=torch.long) for k, v in out.items()}
return out
# ------------------------------
# Save / Load
# ------------------------------
def save_vocabulary(self, save_directory: str, filename_prefix: Optional[str] = None) -> Tuple[str]:
if not os.path.isdir(save_directory): os.makedirs(save_directory)
vocab_file = os.path.join(save_directory,(filename_prefix+"-" if filename_prefix else "")+"vocab.json")
with open(vocab_file,"w",encoding="utf-8") as f: json.dump(self.token_to_id,f,ensure_ascii=False,indent=2)
return (vocab_file,)
def save_pretrained(self, save_directory: Union[str, os.PathLike], filename_prefix: Optional[str]=None, **kwargs):
if not os.path.exists(save_directory): os.makedirs(save_directory)
self.save_vocabulary(save_directory, filename_prefix)
config_file = os.path.join(save_directory,"tokenizer_config.json")
with open(config_file,"w",encoding="utf-8") as f:
json.dump({
"tokenizer_class": self.__class__.__name__,
"model_max_length": self.model_max_length,
"padding_side": self.padding_side,
"truncation_side": self.truncation_side,
"special_tokens": {
"bos_token": self.bos_token,
"eos_token": self.eos_token,
"pad_token": self.pad_token,
"unk_token": self.unk_token,
"mask_token": self.mask_token,
}
},f,ensure_ascii=False,indent=2)
return (save_directory,)
@classmethod
def from_pretrained(cls, pretrained_model_name_or_path, **kwargs):
if os.path.isdir(pretrained_model_name_or_path):
vocab_file = os.path.join(pretrained_model_name_or_path,"vocab.json")
config_file = os.path.join(pretrained_model_name_or_path,"tokenizer_config.json")
config = {}
if os.path.exists(config_file):
with open(config_file,"r",encoding="utf-8") as f: config=json.load(f)
return cls(vocab_file=vocab_file, **{**config,**kwargs})
else:
raise NotImplementedError("Loading from Hub not implemented yet")
# ------------------------------
# SELFIES variant
# ------------------------------
class FastChemTokenizerSelfies(FastChemTokenizer):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs) # ✅ ensures BOS/EOS etc. are set
"""SELFIES variant that handles whitespace-separated tokens."""
def _encode_core(self, text: str) -> List[int]:
result_ids, i, n = [], 0, len(text)
while i < n:
if text[i].isspace(): i += 1; continue
node, j = self.trie_root, i
last_match_id, last_match_end = None, i
while j < n and text[j] in node.children:
node = node.children[text[j]]; j += 1
if node.token_id is not None:
last_match_id, last_match_end = node.token_id, j
if last_match_id is not None:
result_ids.append(last_match_id); i = last_match_end
else:
result_ids.append(self.token_to_id.get(text[i], self.unk_token_id)); i += 1
return result_ids
def convert_tokens_to_string(self, tokens: List[str]) -> str: return " ".join(tokens)
def decode(self, token_ids, skip_special_tokens=False, **kwargs):
if isinstance(token_ids, torch.Tensor): token_ids = token_ids.tolist()
special_ids = {self.bos_token_id,self.eos_token_id,self.pad_token_id,self.mask_token_id} if skip_special_tokens else set()
tokens = [self.id_to_token.get(tid,self.unk_token) for tid in token_ids if tid not in special_ids]
return " ".join(tokens)