Suya OCR API — vLLM-backed, OpenAI-compatible OCR service

FastAPI service wrapping the Surya-OCR-2 model (datalab-to) served through vLLM:
legacy /v1/api/ai/* endpoints, an OpenAI-compatible /v1/chat/completions endpoint,
a coalescing request batcher, a local OCR CLI, Docker packaging, multilingual
example outputs, and quantization/concurrency benchmarks.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
Fu Dai
2026-06-17 10:20:02 +04:00
co-authored by Claude Opus 4.8
commit 1a585693be
147 changed files with 13827 additions and 0 deletions
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import math
from typing import List, Optional
from tqdm import tqdm
from surya.common.predictor import BasePredictor
from surya.ocr_error.loader import OCRErrorModelLoader
from surya.ocr_error.model.config import ID2LABEL
from surya.ocr_error.schema import OCRErrorDetectionResult
from surya.settings import settings
class OCRErrorPredictor(BasePredictor):
model_loader_cls = OCRErrorModelLoader
batch_size = settings.OCR_ERROR_BATCH_SIZE
default_batch_sizes = {"cpu": 8, "mps": 8, "cuda": 64}
def __call__(self, texts: List[str], batch_size: Optional[int] = None):
return self.batch_ocr_error_detection(texts, batch_size)
def batch_ocr_error_detection(
self, texts: List[str], batch_size: Optional[int] = None
):
if batch_size is None:
batch_size = self.get_batch_size()
num_batches = math.ceil(len(texts) / batch_size)
texts_processed = self.processor(
texts, padding="longest", truncation=True, return_tensors="pt"
)
predictions = []
for batch_idx in tqdm(
range(num_batches),
desc="Running OCR Error Detection",
disable=self.disable_tqdm,
):
start_idx, end_idx = batch_idx * batch_size, (batch_idx + 1) * batch_size
batch_input_ids = texts_processed.input_ids[start_idx:end_idx].to(
self.model.device
)
batch_attention_mask = texts_processed.attention_mask[start_idx:end_idx].to(
self.model.device
)
with settings.INFERENCE_MODE():
pred = self.model(batch_input_ids, attention_mask=batch_attention_mask)
logits = pred.logits.argmax(dim=1).cpu().tolist()
predictions.extend(logits)
return OCRErrorDetectionResult(
texts=texts, labels=[ID2LABEL[p] for p in predictions]
)
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from typing import Optional
from surya.common.load import ModelLoader
from surya.logging import get_logger
from surya.ocr_error.model.config import DistilBertConfig
from surya.ocr_error.model.encoder import DistilBertForSequenceClassification
from surya.ocr_error.tokenizer import DistilBertTokenizer
from surya.settings import settings
logger = get_logger()
class OCRErrorModelLoader(ModelLoader):
def __init__(self, checkpoint: Optional[str] = None):
super().__init__(checkpoint)
if self.checkpoint is None:
self.checkpoint = settings.OCR_ERROR_MODEL_CHECKPOINT
def model(
self,
device=settings.TORCH_DEVICE_MODEL,
dtype=settings.MODEL_DTYPE,
attention_implementation: Optional[str] = None,
) -> DistilBertForSequenceClassification:
if device is None:
device = settings.TORCH_DEVICE_MODEL
if dtype is None:
dtype = settings.MODEL_DTYPE
config = DistilBertConfig.from_pretrained(self.checkpoint)
model = (
DistilBertForSequenceClassification.from_pretrained(
self.checkpoint,
dtype=dtype,
config=config,
)
.to(device)
.eval()
)
return model
def processor(
self, device=settings.TORCH_DEVICE_MODEL, dtype=settings.MODEL_DTYPE
) -> DistilBertTokenizer:
return DistilBertTokenizer.from_pretrained(self.checkpoint)
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from collections import OrderedDict
from typing import Mapping
from transformers.configuration_utils import PretrainedConfig
from transformers.onnx import OnnxConfig
from surya.common.s3 import S3DownloaderMixin
ID2LABEL = {
0: 'good',
1: 'bad'
}
class DistilBertConfig(S3DownloaderMixin, PretrainedConfig):
model_type = "distilbert"
attribute_map = {
"hidden_size": "dim",
"num_attention_heads": "n_heads",
"num_hidden_layers": "n_layers",
}
def __init__(
self,
vocab_size=30522,
max_position_embeddings=512,
sinusoidal_pos_embds=False,
n_layers=6,
n_heads=12,
dim=768,
hidden_dim=4 * 768,
dropout=0.1,
attention_dropout=0.1,
activation="gelu",
initializer_range=0.02,
qa_dropout=0.1,
seq_classif_dropout=0.2,
pad_token_id=0,
**kwargs,
):
self.vocab_size = vocab_size
self.max_position_embeddings = max_position_embeddings
self.sinusoidal_pos_embds = sinusoidal_pos_embds
self.n_layers = n_layers
self.n_heads = n_heads
self.dim = dim
self.hidden_dim = hidden_dim
self.dropout = dropout
self.attention_dropout = attention_dropout
self.activation = activation
self.initializer_range = initializer_range
self.qa_dropout = qa_dropout
self.seq_classif_dropout = seq_classif_dropout
super().__init__(**kwargs, pad_token_id=pad_token_id)
class DistilBertOnnxConfig(OnnxConfig):
@property
def inputs(self) -> Mapping[str, Mapping[int, str]]:
if self.task == "multiple-choice":
dynamic_axis = {0: "batch", 1: "choice", 2: "sequence"}
else:
dynamic_axis = {0: "batch", 1: "sequence"}
return OrderedDict(
[
("input_ids", dynamic_axis),
("attention_mask", dynamic_axis),
]
)
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from __future__ import annotations
import math
from typing import Optional, Set, List, Tuple, Union, Dict
import numpy as np
import torch
from torch import nn
from torch.nn import functional as F, MSELoss, CrossEntropyLoss, BCEWithLogitsLoss
from transformers import apply_chunking_to_forward
from transformers.activations import get_activation
from transformers.modeling_outputs import BaseModelOutput, SequenceClassifierOutput
from transformers.pytorch_utils import (
find_pruneable_heads_and_indices,
prune_linear_layer,
)
from transformers.utils import (
is_flash_attn_greater_or_equal_2_10,
)
from surya.common.pretrained import SuryaPreTrainedModel
from surya.common.s3 import S3DownloaderMixin
from surya.ocr_error.model.config import DistilBertConfig
def _get_unpad_data(attention_mask):
seqlens_in_batch = attention_mask.sum(dim=-1, dtype=torch.int32)
indices = torch.nonzero(attention_mask.flatten(), as_tuple=False).flatten()
max_seqlen_in_batch = seqlens_in_batch.max().item()
cu_seqlens = F.pad(torch.cumsum(seqlens_in_batch, dim=0, dtype=torch.int32), (1, 0))
return (
indices,
cu_seqlens,
max_seqlen_in_batch,
)
def create_sinusoidal_embeddings(n_pos: int, dim: int, out: torch.Tensor):
position_enc = np.array(
[
[pos / np.power(10000, 2 * (j // 2) / dim) for j in range(dim)]
for pos in range(n_pos)
]
)
out.requires_grad = False
out[:, 0::2] = torch.FloatTensor(np.sin(position_enc[:, 0::2]))
out[:, 1::2] = torch.FloatTensor(np.cos(position_enc[:, 1::2]))
out.detach_()
class Embeddings(nn.Module):
def __init__(self, config: DistilBertConfig):
super().__init__()
self.word_embeddings = nn.Embedding(
config.vocab_size, config.dim, padding_idx=config.pad_token_id
)
self.position_embeddings = nn.Embedding(
config.max_position_embeddings, config.dim
)
self.LayerNorm = nn.LayerNorm(config.dim, eps=1e-12)
self.dropout = nn.Dropout(config.dropout)
self.register_buffer(
"position_ids",
torch.arange(config.max_position_embeddings).expand((1, -1)),
persistent=False,
)
def forward(
self, input_ids: torch.Tensor, input_embeds: Optional[torch.Tensor] = None
) -> torch.Tensor:
"""
Parameters:
input_ids (torch.Tensor):
torch.tensor(bs, max_seq_length) The token ids to embed.
input_embeds (*optional*, torch.Tensor):
The pre-computed word embeddings. Can only be passed if the input ids are `None`.
Returns: torch.tensor(bs, max_seq_length, dim) The embedded tokens (plus position embeddings, no token_type
embeddings)
"""
if input_ids is not None:
input_embeds = self.word_embeddings(input_ids) # (bs, max_seq_length, dim)
seq_length = input_embeds.size(1)
# Setting the position-ids to the registered buffer in constructor, it helps
# when tracing the model without passing position-ids, solves
# isues similar to issue #5664
if hasattr(self, "position_ids"):
position_ids = self.position_ids[:, :seq_length]
else:
position_ids = torch.arange(
seq_length, dtype=torch.long, device=input_ids.device
) # (max_seq_length)
position_ids = position_ids.unsqueeze(0).expand_as(
input_ids
) # (bs, max_seq_length)
position_embeddings = self.position_embeddings(
position_ids
) # (bs, max_seq_length, dim)
embeddings = input_embeds + position_embeddings # (bs, max_seq_length, dim)
embeddings = self.LayerNorm(embeddings) # (bs, max_seq_length, dim)
embeddings = self.dropout(embeddings) # (bs, max_seq_length, dim)
return embeddings
class MultiHeadSelfAttention(nn.Module):
def __init__(self, config: DistilBertConfig):
super().__init__()
self.config = config
self.n_heads = config.n_heads
self.dim = config.dim
self.dropout = nn.Dropout(p=config.attention_dropout)
self.is_causal = False
# Have an even number of multi heads that divide the dimensions
if self.dim % self.n_heads != 0:
# Raise value errors for even multi-head attention nodes
raise ValueError(
f"self.n_heads: {self.n_heads} must divide self.dim: {self.dim} evenly"
)
self.q_lin = nn.Linear(in_features=config.dim, out_features=config.dim)
self.k_lin = nn.Linear(in_features=config.dim, out_features=config.dim)
self.v_lin = nn.Linear(in_features=config.dim, out_features=config.dim)
self.out_lin = nn.Linear(in_features=config.dim, out_features=config.dim)
self.pruned_heads: Set[int] = set()
self.attention_head_size = self.dim // self.n_heads
def prune_heads(self, heads: List[int]):
if len(heads) == 0:
return
heads, index = find_pruneable_heads_and_indices(
heads, self.n_heads, self.attention_head_size, self.pruned_heads
)
# Prune linear layers
self.q_lin = prune_linear_layer(self.q_lin, index)
self.k_lin = prune_linear_layer(self.k_lin, index)
self.v_lin = prune_linear_layer(self.v_lin, index)
self.out_lin = prune_linear_layer(self.out_lin, index, dim=1)
# Update hyper params
self.n_heads = self.n_heads - len(heads)
self.dim = self.attention_head_size * self.n_heads
self.pruned_heads = self.pruned_heads.union(heads)
def forward(
self,
query: torch.Tensor,
key: torch.Tensor,
value: torch.Tensor,
mask: torch.Tensor,
head_mask: Optional[torch.Tensor] = None,
output_attentions: bool = False,
) -> Tuple[torch.Tensor, ...]:
"""
Parameters:
query: torch.tensor(bs, seq_length, dim)
key: torch.tensor(bs, seq_length, dim)
value: torch.tensor(bs, seq_length, dim)
mask: torch.tensor(bs, seq_length)
Returns:
weights: torch.tensor(bs, n_heads, seq_length, seq_length) Attention weights context: torch.tensor(bs,
seq_length, dim) Contextualized layer. Optional: only if `output_attentions=True`
"""
bs, q_length, dim = query.size()
k_length = key.size(1)
# assert dim == self.dim, f'Dimensions do not match: {dim} input vs {self.dim} configured'
# assert key.size() == value.size()
dim_per_head = self.dim // self.n_heads
mask_reshp = (bs, 1, 1, k_length)
def shape(x: torch.Tensor) -> torch.Tensor:
"""separate heads"""
return x.view(bs, -1, self.n_heads, dim_per_head).transpose(1, 2)
def unshape(x: torch.Tensor) -> torch.Tensor:
"""group heads"""
return (
x.transpose(1, 2).contiguous().view(bs, -1, self.n_heads * dim_per_head)
)
q = shape(self.q_lin(query)) # (bs, n_heads, q_length, dim_per_head)
k = shape(self.k_lin(key)) # (bs, n_heads, k_length, dim_per_head)
v = shape(self.v_lin(value)) # (bs, n_heads, k_length, dim_per_head)
q = q / math.sqrt(dim_per_head) # (bs, n_heads, q_length, dim_per_head)
scores = torch.matmul(q, k.transpose(2, 3)) # (bs, n_heads, q_length, k_length)
mask = (
(mask == 0).view(mask_reshp).expand_as(scores)
) # (bs, n_heads, q_length, k_length)
scores = scores.masked_fill(
mask, torch.tensor(torch.finfo(scores.dtype).min)
) # (bs, n_heads, q_length, k_length)
weights = nn.functional.softmax(
scores, dim=-1
) # (bs, n_heads, q_length, k_length)
weights = self.dropout(weights) # (bs, n_heads, q_length, k_length)
# Mask heads if we want to
if head_mask is not None:
weights = weights * head_mask
context = torch.matmul(weights, v) # (bs, n_heads, q_length, dim_per_head)
context = unshape(context) # (bs, q_length, dim)
context = self.out_lin(context) # (bs, q_length, dim)
if output_attentions:
return (context, weights)
else:
return (context,)
class DistilBertFlashAttention2(MultiHeadSelfAttention):
"""
DistilBert flash attention module. This module inherits from `MultiHeadSelfAttention` as the weights of the module
stays untouched. The only required change would be on the forward pass where it needs to correctly call the public
API of flash attention and deal with padding tokens in case the input contains any of them.
"""
# Copied from transformers.models.llama.modeling_llama.LlamaFlashAttention2.__init__
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# TODO: Should be removed once Flash Attention for RoCm is bumped to 2.1.
# flash_attn<2.1 generates top-left aligned causal mask, while what is needed here is bottom-right alignement, that was made default for flash_attn>=2.1. This attribute is used to handle this difference. Reference: https://github.com/Dao-AILab/flash-attention/releases/tag/v2.1.0.
# Beware that with flash_attn<2.1, using q_seqlen != k_seqlen (except for the case q_seqlen == 1) produces a wrong mask (top-left).
self._flash_attn_uses_top_left_mask = not is_flash_attn_greater_or_equal_2_10()
def forward(
self,
query: torch.Tensor,
key: torch.Tensor,
value: torch.Tensor,
mask: torch.Tensor,
head_mask: Optional[torch.Tensor] = None,
output_attentions: bool = False,
) -> Tuple[torch.Tensor, ...]:
"""
Parameters:
query: torch.tensor(bs, seq_length, dim)
key: torch.tensor(bs, seq_length, dim)
value: torch.tensor(bs, seq_length, dim)
mask: torch.tensor(bs, seq_length)
Returns:
weights: torch.tensor(bs, n_heads, seq_length, seq_length) Attention weights context: torch.tensor(bs,
seq_length, dim) Contextualized layer. Optional: only if `output_attentions=True`
"""
batch_size, q_length, dim = query.size()
dim_per_head = self.dim // self.n_heads
def reshape(x: torch.Tensor) -> torch.Tensor:
"""separate heads"""
return x.view(batch_size, -1, self.n_heads, dim_per_head)
# Flash attention requires the input to have the shape
# batch_size x seq_length x head_dim x hidden_dim
query_states = reshape(self.q_lin(query))
key_states = reshape(self.k_lin(key))
value_states = reshape(self.v_lin(value))
attn_dropout = self.config.attention_dropout if self.training else 0.0
# In PEFT, usually we cast the layer norms in float32 for training stability reasons
# therefore the input hidden states gets silently casted in float32. Hence, we need
# cast them back in the correct dtype just to be sure everything works as expected.
# This might slowdown training & inference so it is recommended to not cast the LayerNorms
# in fp32. (LlamaRMSNorm handles it correctly)
if query_states.dtype == torch.float32:
if torch.is_autocast_enabled():
target_dtype = torch.get_autocast_gpu_dtype()
# Handle the case where the model is quantized
elif hasattr(self.config, "_pre_quantization_dtype"):
target_dtype = self.config._pre_quantization_dtype
else:
target_dtype = self.q_lin.weight.dtype
query_states = query_states.to(target_dtype)
key_states = key_states.to(target_dtype)
value_states = value_states.to(target_dtype)
attn_weights = self._flash_attention_forward(
query_states, key_states, value_states, mask, q_length, dropout=attn_dropout
)
attn_weights_reshaped = attn_weights.reshape(
batch_size, q_length, self.n_heads * dim_per_head
)
attn_output = self.out_lin(attn_weights_reshaped)
if output_attentions:
return (attn_output, attn_weights)
else:
return (attn_output,)
# Copied from transformers.models.llama.modeling_llama.LlamaFlashAttention2._flash_attention_forward with causal=True->causal=False
def _flash_attention_forward(
self,
query_states,
key_states,
value_states,
attention_mask,
query_length,
dropout=0.0,
softmax_scale=None,
):
"""
Calls the forward method of Flash Attention - if the input hidden states contain at least one padding token
first unpad the input, then computes the attention scores and pad the final attention scores.
Args:
query_states (`torch.Tensor`):
Input query states to be passed to Flash Attention API
key_states (`torch.Tensor`):
Input key states to be passed to Flash Attention API
value_states (`torch.Tensor`):
Input value states to be passed to Flash Attention API
attention_mask (`torch.Tensor`):
The padding mask - corresponds to a tensor of size `(batch_size, seq_len)` where 0 stands for the
position of padding tokens and 1 for the position of non-padding tokens.
dropout (`float`):
Attention dropout
softmax_scale (`float`, *optional*):
The scaling of QK^T before applying softmax. Default to 1 / sqrt(head_dim)
"""
from flash_attn import flash_attn_func, flash_attn_varlen_func
from flash_attn.bert_padding import pad_input
if not self._flash_attn_uses_top_left_mask:
causal = self.is_causal
else:
# TODO: Remove the `query_length != 1` check once Flash Attention for RoCm is bumped to 2.1. For details, please see the comment in LlamaFlashAttention2 __init__.
causal = self.is_causal and query_length != 1
# Contains at least one padding token in the sequence
if attention_mask is not None:
batch_size = query_states.shape[0]
(
query_states,
key_states,
value_states,
indices_q,
cu_seq_lens,
max_seq_lens,
) = self._upad_input(
query_states, key_states, value_states, attention_mask, query_length
)
cu_seqlens_q, cu_seqlens_k = cu_seq_lens
max_seqlen_in_batch_q, max_seqlen_in_batch_k = max_seq_lens
attn_output_unpad = flash_attn_varlen_func(
query_states,
key_states,
value_states,
cu_seqlens_q=cu_seqlens_q,
cu_seqlens_k=cu_seqlens_k,
max_seqlen_q=max_seqlen_in_batch_q,
max_seqlen_k=max_seqlen_in_batch_k,
dropout_p=dropout,
softmax_scale=softmax_scale,
causal=causal,
)
attn_output = pad_input(
attn_output_unpad, indices_q, batch_size, query_length
)
else:
attn_output = flash_attn_func(
query_states,
key_states,
value_states,
dropout,
softmax_scale=softmax_scale,
causal=causal,
)
return attn_output
# Copied from transformers.models.llama.modeling_llama.LlamaFlashAttention2._upad_input with num_heads->n_heads
def _upad_input(
self, query_layer, key_layer, value_layer, attention_mask, query_length
):
from flash_attn.bert_padding import index_first_axis, unpad_input
indices_k, cu_seqlens_k, max_seqlen_in_batch_k = _get_unpad_data(attention_mask)
batch_size, kv_seq_len, num_key_value_heads, head_dim = key_layer.shape
key_layer = index_first_axis(
key_layer.reshape(batch_size * kv_seq_len, num_key_value_heads, head_dim),
indices_k,
)
value_layer = index_first_axis(
value_layer.reshape(batch_size * kv_seq_len, num_key_value_heads, head_dim),
indices_k,
)
if query_length == kv_seq_len:
query_layer = index_first_axis(
query_layer.reshape(batch_size * kv_seq_len, self.n_heads, head_dim),
indices_k,
)
cu_seqlens_q = cu_seqlens_k
max_seqlen_in_batch_q = max_seqlen_in_batch_k
indices_q = indices_k
elif query_length == 1:
max_seqlen_in_batch_q = 1
cu_seqlens_q = torch.arange(
batch_size + 1, dtype=torch.int32, device=query_layer.device
) # There is a memcpy here, that is very bad.
indices_q = cu_seqlens_q[:-1]
query_layer = query_layer.squeeze(1)
else:
# The -q_len: slice assumes left padding.
attention_mask = attention_mask[:, -query_length:]
query_layer, indices_q, cu_seqlens_q, max_seqlen_in_batch_q = unpad_input(
query_layer, attention_mask
)
return (
query_layer,
key_layer,
value_layer,
indices_q,
(cu_seqlens_q, cu_seqlens_k),
(max_seqlen_in_batch_q, max_seqlen_in_batch_k),
)
class FFN(nn.Module):
def __init__(self, config: DistilBertConfig):
super().__init__()
self.dropout = nn.Dropout(p=config.dropout)
self.chunk_size_feed_forward = config.chunk_size_feed_forward
self.seq_len_dim = 1
self.lin1 = nn.Linear(in_features=config.dim, out_features=config.hidden_dim)
self.lin2 = nn.Linear(in_features=config.hidden_dim, out_features=config.dim)
self.activation = get_activation(config.activation)
def forward(self, input: torch.Tensor) -> torch.Tensor:
return apply_chunking_to_forward(
self.ff_chunk, self.chunk_size_feed_forward, self.seq_len_dim, input
)
def ff_chunk(self, input: torch.Tensor) -> torch.Tensor:
x = self.lin1(input)
x = self.activation(x)
x = self.lin2(x)
x = self.dropout(x)
return x
DISTILBERT_ATTENTION_CLASSES = {
"eager": MultiHeadSelfAttention,
"flash_attention_2": DistilBertFlashAttention2,
}
class TransformerBlock(nn.Module):
def __init__(self, config: DistilBertConfig):
super().__init__()
# Have an even number of Configure multi-heads
if config.dim % config.n_heads != 0:
raise ValueError(
f"config.n_heads {config.n_heads} must divide config.dim {config.dim} evenly"
)
self.attention = DISTILBERT_ATTENTION_CLASSES[config._attn_implementation](
config
)
self.sa_layer_norm = nn.LayerNorm(normalized_shape=config.dim, eps=1e-12)
self.ffn = FFN(config)
self.output_layer_norm = nn.LayerNorm(normalized_shape=config.dim, eps=1e-12)
def forward(
self,
x: torch.Tensor,
attn_mask: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
output_attentions: bool = False,
) -> Tuple[torch.Tensor, ...]:
"""
Parameters:
x: torch.tensor(bs, seq_length, dim)
attn_mask: torch.tensor(bs, seq_length)
Returns:
sa_weights: torch.tensor(bs, n_heads, seq_length, seq_length) The attention weights ffn_output:
torch.tensor(bs, seq_length, dim) The output of the transformer block contextualization.
"""
# Self-Attention
sa_output = self.attention(
query=x,
key=x,
value=x,
mask=attn_mask,
head_mask=head_mask,
output_attentions=output_attentions,
)
if output_attentions:
sa_output, sa_weights = (
sa_output # (bs, seq_length, dim), (bs, n_heads, seq_length, seq_length)
)
else: # To handle these `output_attentions` or `output_hidden_states` cases returning tuples
sa_output = sa_output[0]
sa_output = self.sa_layer_norm(sa_output + x) # (bs, seq_length, dim)
# Feed Forward Network
ffn_output = self.ffn(sa_output) # (bs, seq_length, dim)
ffn_output: torch.Tensor = self.output_layer_norm(
ffn_output + sa_output
) # (bs, seq_length, dim)
output = (ffn_output,)
if output_attentions:
output = (sa_weights,) + output
return output
class Transformer(nn.Module):
def __init__(self, config: DistilBertConfig):
super().__init__()
self.n_layers = config.n_layers
self.layer = nn.ModuleList(
[TransformerBlock(config) for _ in range(config.n_layers)]
)
self.gradient_checkpointing = False
def forward(
self,
x: torch.Tensor,
attn_mask: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
output_attentions: bool = False,
output_hidden_states: bool = False,
return_dict: Optional[bool] = None,
) -> Union[BaseModelOutput, Tuple[torch.Tensor, ...]]: # docstyle-ignore
"""
Parameters:
x: torch.tensor(bs, seq_length, dim) Input sequence embedded.
attn_mask: torch.tensor(bs, seq_length) Attention mask on the sequence.
Returns:
hidden_state: torch.tensor(bs, seq_length, dim) Sequence of hidden states in the last (top)
layer all_hidden_states: Tuple[torch.tensor(bs, seq_length, dim)]
Tuple of length n_layers with the hidden states from each layer.
Optional: only if output_hidden_states=True
all_attentions: Tuple[torch.tensor(bs, n_heads, seq_length, seq_length)]
Tuple of length n_layers with the attention weights from each layer
Optional: only if output_attentions=True
"""
all_hidden_states = () if output_hidden_states else None
all_attentions = () if output_attentions else None
hidden_state = x
for i, layer_module in enumerate(self.layer):
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_state,)
if self.gradient_checkpointing and self.training:
layer_outputs = self._gradient_checkpointing_func(
layer_module.__call__,
hidden_state,
attn_mask,
head_mask[i],
output_attentions,
)
else:
layer_outputs = layer_module(
hidden_state,
attn_mask,
head_mask[i],
output_attentions,
)
hidden_state = layer_outputs[-1]
if output_attentions:
if len(layer_outputs) != 2:
raise ValueError(
f"The length of the layer_outputs should be 2, but it is {len(layer_outputs)}"
)
attentions = layer_outputs[0]
all_attentions = all_attentions + (attentions,)
else:
if len(layer_outputs) != 1:
raise ValueError(
f"The length of the layer_outputs should be 1, but it is {len(layer_outputs)}"
)
# Add last layer
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_state,)
if not return_dict:
return tuple(
v
for v in [hidden_state, all_hidden_states, all_attentions]
if v is not None
)
return BaseModelOutput(
last_hidden_state=hidden_state,
hidden_states=all_hidden_states,
attentions=all_attentions,
)
class DistilBertPreTrainedModel(SuryaPreTrainedModel):
"""
An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained
models.
"""
config_class = DistilBertConfig
load_tf_weights = None
base_model_prefix = "distilbert"
supports_gradient_checkpointing = True
_supports_flash_attn_2 = True
def _init_weights(self, module: nn.Module):
"""Initialize the weights."""
if isinstance(module, nn.Linear):
# Slightly different from the TF version which uses truncated_normal for initialization
# cf https://github.com/pytorch/pytorch/pull/5617
module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
if module.bias is not None:
module.bias.data.zero_()
elif isinstance(module, nn.Embedding):
module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
if module.padding_idx is not None:
module.weight.data[module.padding_idx].zero_()
elif isinstance(module, nn.LayerNorm):
module.bias.data.zero_()
module.weight.data.fill_(1.0)
elif isinstance(module, Embeddings) and self.config.sinusoidal_pos_embds:
create_sinusoidal_embeddings(
self.config.max_position_embeddings,
self.config.dim,
module.position_embeddings.weight,
)
class DistilBertModel(DistilBertPreTrainedModel):
def __init__(self, config: DistilBertConfig):
super().__init__(config)
self.embeddings = Embeddings(config) # Embeddings
self.transformer = Transformer(config) # Encoder
self._use_flash_attention_2 = config._attn_implementation == "flash_attention_2"
# Initialize weights and apply final processing
self.post_init()
def get_position_embeddings(self) -> nn.Embedding:
"""
Returns the position embeddings
"""
return self.embeddings.position_embeddings
def resize_position_embeddings(self, new_num_position_embeddings: int):
"""
Resizes position embeddings of the model if `new_num_position_embeddings != config.max_position_embeddings`.
Arguments:
new_num_position_embeddings (`int`):
The number of new position embedding matrix. If position embeddings are learned, increasing the size
will add newly initialized vectors at the end, whereas reducing the size will remove vectors from the
end. If position embeddings are not learned (*e.g.* sinusoidal position embeddings), increasing the
size will add correct vectors at the end following the position encoding algorithm, whereas reducing
the size will remove vectors from the end.
"""
num_position_embeds_diff = (
new_num_position_embeddings - self.config.max_position_embeddings
)
# no resizing needs to be done if the length stays the same
if num_position_embeds_diff == 0:
return
self.config.max_position_embeddings = new_num_position_embeddings
old_position_embeddings_weight = (
self.embeddings.position_embeddings.weight.clone()
)
self.embeddings.position_embeddings = nn.Embedding(
self.config.max_position_embeddings, self.config.dim
)
if self.config.sinusoidal_pos_embds:
create_sinusoidal_embeddings(
n_pos=self.config.max_position_embeddings,
dim=self.config.dim,
out=self.position_embeddings.weight,
)
else:
with torch.no_grad():
if num_position_embeds_diff > 0:
self.embeddings.position_embeddings.weight[
:-num_position_embeds_diff
] = nn.Parameter(old_position_embeddings_weight)
else:
self.embeddings.position_embeddings.weight = nn.Parameter(
old_position_embeddings_weight[:num_position_embeds_diff]
)
# move position_embeddings to correct device
self.embeddings.position_embeddings.to(self.device)
def get_input_embeddings(self) -> nn.Embedding:
return self.embeddings.word_embeddings
def set_input_embeddings(self, new_embeddings: nn.Embedding):
self.embeddings.word_embeddings = new_embeddings
def _prune_heads(self, heads_to_prune: Dict[int, List[List[int]]]):
"""
Prunes heads of the model. heads_to_prune: dict of {layer_num: list of heads to prune in this layer} See base
class PreTrainedModel
"""
for layer, heads in heads_to_prune.items():
self.transformer.layer[layer].attention.prune_heads(heads)
def forward(
self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[BaseModelOutput, Tuple[torch.Tensor, ...]]:
output_attentions = (
output_attentions
if output_attentions is not None
else self.config.output_attentions
)
output_hidden_states = (
output_hidden_states
if output_hidden_states is not None
else self.config.output_hidden_states
)
return_dict = (
return_dict if return_dict is not None else self.config.use_return_dict
)
if input_ids is not None and inputs_embeds is not None:
raise ValueError(
"You cannot specify both input_ids and inputs_embeds at the same time"
)
elif input_ids is not None:
self.warn_if_padding_and_no_attention_mask(input_ids, attention_mask)
input_shape = input_ids.size()
elif inputs_embeds is not None:
input_shape = inputs_embeds.size()[:-1]
else:
raise ValueError("You have to specify either input_ids or inputs_embeds")
device = input_ids.device if input_ids is not None else inputs_embeds.device
# Prepare head mask if needed
head_mask = self.get_head_mask(head_mask, self.config.num_hidden_layers)
embeddings = self.embeddings(input_ids, inputs_embeds) # (bs, seq_length, dim)
if self._use_flash_attention_2:
attention_mask = (
attention_mask
if (attention_mask is not None and 0 in attention_mask)
else None
)
else:
if attention_mask is None:
attention_mask = torch.ones(
input_shape, device=device
) # (bs, seq_length)
return self.transformer(
x=embeddings,
attn_mask=attention_mask,
head_mask=head_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
class DistilBertForSequenceClassification(S3DownloaderMixin, DistilBertPreTrainedModel):
def __init__(self, config: DistilBertConfig, **kwargs):
super().__init__(config, **kwargs)
self.num_labels = config.num_labels
self.config = config
self.distilbert = DistilBertModel(config)
self.pre_classifier = nn.Linear(config.dim, config.dim)
self.classifier = nn.Linear(config.dim, config.num_labels)
self.dropout = nn.Dropout(config.seq_classif_dropout)
# Initialize weights and apply final processing
self.post_init()
def get_position_embeddings(self) -> nn.Embedding:
"""
Returns the position embeddings
"""
return self.distilbert.get_position_embeddings()
def resize_position_embeddings(self, new_num_position_embeddings: int):
"""
Resizes position embeddings of the model if `new_num_position_embeddings != config.max_position_embeddings`.
Arguments:
new_num_position_embeddings (`int`):
The number of new position embedding matrix. If position embeddings are learned, increasing the size
will add newly initialized vectors at the end, whereas reducing the size will remove vectors from the
end. If position embeddings are not learned (*e.g.* sinusoidal position embeddings), increasing the
size will add correct vectors at the end following the position encoding algorithm, whereas reducing
the size will remove vectors from the end.
"""
self.distilbert.resize_position_embeddings(new_num_position_embeddings)
def forward(
self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
labels: Optional[torch.LongTensor] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[SequenceClassifierOutput, Tuple[torch.Tensor, ...]]:
r"""
labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
Labels for computing the sequence classification/regression loss. Indices should be in `[0, ...,
config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If
`config.num_labels > 1` a classification loss is computed (Cross-Entropy).
"""
return_dict = (
return_dict if return_dict is not None else self.config.use_return_dict
)
distilbert_output = self.distilbert(
input_ids=input_ids,
attention_mask=attention_mask,
head_mask=head_mask,
inputs_embeds=inputs_embeds,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_state = distilbert_output[0] # (bs, seq_len, dim)
pooled_output = hidden_state[:, 0] # (bs, dim)
pooled_output = self.pre_classifier(pooled_output) # (bs, dim)
pooled_output = nn.ReLU()(pooled_output) # (bs, dim)
pooled_output = self.dropout(pooled_output) # (bs, dim)
logits = self.classifier(pooled_output) # (bs, num_labels)
loss = None
if labels is not None:
if self.config.problem_type is None:
if self.num_labels == 1:
self.config.problem_type = "regression"
elif self.num_labels > 1 and (
labels.dtype == torch.long or labels.dtype == torch.int
):
self.config.problem_type = "single_label_classification"
else:
self.config.problem_type = "multi_label_classification"
if self.config.problem_type == "regression":
loss_fct = MSELoss()
if self.num_labels == 1:
loss = loss_fct(logits.squeeze(), labels.squeeze())
else:
loss = loss_fct(logits, labels)
elif self.config.problem_type == "single_label_classification":
loss_fct = CrossEntropyLoss()
loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))
elif self.config.problem_type == "multi_label_classification":
loss_fct = BCEWithLogitsLoss()
loss = loss_fct(logits, labels)
if not return_dict:
output = (logits,) + distilbert_output[1:]
return ((loss,) + output) if loss is not None else output
return SequenceClassifierOutput(
loss=loss,
logits=logits,
hidden_states=distilbert_output.hidden_states,
attentions=distilbert_output.attentions,
)
+8
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from typing import List
from pydantic import BaseModel
class OCRErrorDetectionResult(BaseModel):
texts: List[str]
labels: List[str]
+525
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import collections
import os
import unicodedata
from typing import List, Optional, Tuple
from transformers.tokenization_utils import (
PreTrainedTokenizer,
_is_control,
_is_punctuation,
_is_whitespace,
)
from surya.common.s3 import S3DownloaderMixin
VOCAB_FILES_NAMES = {"vocab_file": "vocab.txt"}
# Copied from transformers.models.bert.tokenization_bert.load_vocab
def load_vocab(vocab_file):
"""Loads a vocabulary file into a dictionary."""
vocab = collections.OrderedDict()
with open(vocab_file, "r", encoding="utf-8") as reader:
tokens = reader.readlines()
for index, token in enumerate(tokens):
token = token.rstrip("\n")
vocab[token] = index
return vocab
# Copied from transformers.models.bert.tokenization_bert.whitespace_tokenize
def whitespace_tokenize(text):
"""Runs basic whitespace cleaning and splitting on a piece of text."""
text = text.strip()
if not text:
return []
tokens = text.split()
return tokens
class DistilBertTokenizer(S3DownloaderMixin, PreTrainedTokenizer):
r"""
Construct a DistilBERT tokenizer. Based on WordPiece.
This tokenizer inherits from [`PreTrainedTokenizer`] which contains most of the main methods. Users should refer to
this superclass for more information regarding those methods.
Args:
vocab_file (`str`):
File containing the vocabulary.
do_lower_case (`bool`, *optional*, defaults to `True`):
Whether or not to lowercase the input when tokenizing.
do_basic_tokenize (`bool`, *optional*, defaults to `True`):
Whether or not to do basic tokenization before WordPiece.
never_split (`Iterable`, *optional*):
Collection of tokens which will never be split during tokenization. Only has an effect when
`do_basic_tokenize=True`
unk_token (`str`, *optional*, defaults to `"[UNK]"`):
The unknown token. A token that is not in the vocabulary cannot be converted to an ID and is set to be this
token instead.
sep_token (`str`, *optional*, defaults to `"[SEP]"`):
The separator token, which is used when building a sequence from multiple sequences, e.g. two sequences for
sequence classification or for a text and a question for question answering. It is also used as the last
token of a sequence built with special tokens.
pad_token (`str`, *optional*, defaults to `"[PAD]"`):
The token used for padding, for example when batching sequences of different lengths.
cls_token (`str`, *optional*, defaults to `"[CLS]"`):
The classifier token which is used when doing sequence classification (classification of the whole sequence
instead of per-token classification). It is the first token of the sequence when built with special tokens.
mask_token (`str`, *optional*, defaults to `"[MASK]"`):
The token used for masking values. This is the token used when training this model with masked language
modeling. This is the token which the model will try to predict.
tokenize_chinese_chars (`bool`, *optional*, defaults to `True`):
Whether or not to tokenize Chinese characters.
This should likely be deactivated for Japanese (see this
[issue](https://github.com/huggingface/transformers/issues/328)).
strip_accents (`bool`, *optional*):
Whether or not to strip all accents. If this option is not specified, then it will be determined by the
value for `lowercase` (as in the original BERT).
"""
vocab_files_names = VOCAB_FILES_NAMES
model_input_names = ["input_ids", "attention_mask"]
def __init__(
self,
vocab_file,
do_lower_case=True,
do_basic_tokenize=True,
never_split=None,
unk_token="[UNK]",
sep_token="[SEP]",
pad_token="[PAD]",
cls_token="[CLS]",
mask_token="[MASK]",
tokenize_chinese_chars=True,
strip_accents=None,
**kwargs,
):
if not os.path.isfile(vocab_file):
raise ValueError(
f"Can't find a vocabulary file at path '{vocab_file}'. To load the vocabulary from a Google pretrained"
" model use `tokenizer = DistilBertTokenizer.from_pretrained(PRETRAINED_MODEL_NAME)`"
)
self.vocab = load_vocab(vocab_file)
self.ids_to_tokens = collections.OrderedDict(
[(ids, tok) for tok, ids in self.vocab.items()]
)
self.do_basic_tokenize = do_basic_tokenize
if do_basic_tokenize:
self.basic_tokenizer = BasicTokenizer(
do_lower_case=do_lower_case,
never_split=never_split,
tokenize_chinese_chars=tokenize_chinese_chars,
strip_accents=strip_accents,
)
self.wordpiece_tokenizer = WordpieceTokenizer(
vocab=self.vocab, unk_token=str(unk_token)
)
super().__init__(
do_lower_case=do_lower_case,
do_basic_tokenize=do_basic_tokenize,
never_split=never_split,
unk_token=unk_token,
sep_token=sep_token,
pad_token=pad_token,
cls_token=cls_token,
mask_token=mask_token,
tokenize_chinese_chars=tokenize_chinese_chars,
strip_accents=strip_accents,
**kwargs,
)
@property
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer.do_lower_case
def do_lower_case(self):
return self.basic_tokenizer.do_lower_case
@property
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer.vocab_size
def vocab_size(self):
return len(self.vocab)
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer.get_vocab
def get_vocab(self):
return dict(self.vocab, **self.added_tokens_encoder)
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer._tokenize
def _tokenize(self, text, split_special_tokens=False):
split_tokens = []
if self.do_basic_tokenize:
for token in self.basic_tokenizer.tokenize(
text,
never_split=self.all_special_tokens
if not split_special_tokens
else None,
):
# If the token is part of the never_split set
if token in self.basic_tokenizer.never_split:
split_tokens.append(token)
else:
split_tokens += self.wordpiece_tokenizer.tokenize(token)
else:
split_tokens = self.wordpiece_tokenizer.tokenize(text)
return split_tokens
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer._convert_token_to_id
def _convert_token_to_id(self, token):
"""Converts a token (str) in an id using the vocab."""
return self.vocab.get(token, self.vocab.get(self.unk_token))
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer._convert_id_to_token
def _convert_id_to_token(self, index):
"""Converts an index (integer) in a token (str) using the vocab."""
return self.ids_to_tokens.get(index, self.unk_token)
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer.convert_tokens_to_string
def convert_tokens_to_string(self, tokens):
"""Converts a sequence of tokens (string) in a single string."""
out_string = " ".join(tokens).replace(" ##", "").strip()
return out_string
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer.build_inputs_with_special_tokens
def build_inputs_with_special_tokens(
self, token_ids_0: List[int], token_ids_1: Optional[List[int]] = None
) -> List[int]:
"""
Build model inputs from a sequence or a pair of sequence for sequence classification tasks by concatenating and
adding special tokens. A BERT sequence has the following format:
- single sequence: `[CLS] X [SEP]`
- pair of sequences: `[CLS] A [SEP] B [SEP]`
Args:
token_ids_0 (`List[int]`):
List of IDs to which the special tokens will be added.
token_ids_1 (`List[int]`, *optional*):
Optional second list of IDs for sequence pairs.
Returns:
`List[int]`: List of [input IDs](../glossary#input-ids) with the appropriate special tokens.
"""
if token_ids_1 is None:
return [self.cls_token_id] + token_ids_0 + [self.sep_token_id]
cls = [self.cls_token_id]
sep = [self.sep_token_id]
return cls + token_ids_0 + sep + token_ids_1 + sep
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer.get_special_tokens_mask
def get_special_tokens_mask(
self,
token_ids_0: List[int],
token_ids_1: Optional[List[int]] = None,
already_has_special_tokens: bool = False,
) -> List[int]:
"""
Retrieve sequence ids from a token list that has no special tokens added. This method is called when adding
special tokens using the tokenizer `prepare_for_model` method.
Args:
token_ids_0 (`List[int]`):
List of IDs.
token_ids_1 (`List[int]`, *optional*):
Optional second list of IDs for sequence pairs.
already_has_special_tokens (`bool`, *optional*, defaults to `False`):
Whether or not the token list is already formatted with special tokens for the model.
Returns:
`List[int]`: A list of integers in the range [0, 1]: 1 for a special token, 0 for a sequence token.
"""
if already_has_special_tokens:
return super().get_special_tokens_mask(
token_ids_0=token_ids_0,
token_ids_1=token_ids_1,
already_has_special_tokens=True,
)
if token_ids_1 is not None:
return [1] + ([0] * len(token_ids_0)) + [1] + ([0] * len(token_ids_1)) + [1]
return [1] + ([0] * len(token_ids_0)) + [1]
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer.create_token_type_ids_from_sequences
def create_token_type_ids_from_sequences(
self, token_ids_0: List[int], token_ids_1: Optional[List[int]] = None
) -> List[int]:
"""
Create a mask from the two sequences passed to be used in a sequence-pair classification task. A BERT sequence
pair mask has the following format:
```
0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1
| first sequence | second sequence |
```
If `token_ids_1` is `None`, this method only returns the first portion of the mask (0s).
Args:
token_ids_0 (`List[int]`):
List of IDs.
token_ids_1 (`List[int]`, *optional*):
Optional second list of IDs for sequence pairs.
Returns:
`List[int]`: List of [token type IDs](../glossary#token-type-ids) according to the given sequence(s).
"""
sep = [self.sep_token_id]
cls = [self.cls_token_id]
if token_ids_1 is None:
return len(cls + token_ids_0 + sep) * [0]
return len(cls + token_ids_0 + sep) * [0] + len(token_ids_1 + sep) * [1]
# Copied from transformers.models.bert.tokenization_bert.BertTokenizer.save_vocabulary
def save_vocabulary(
self, save_directory: str, filename_prefix: Optional[str] = None
) -> Tuple[str]:
index = 0
if os.path.isdir(save_directory):
vocab_file = os.path.join(
save_directory,
(filename_prefix + "-" if filename_prefix else "")
+ VOCAB_FILES_NAMES["vocab_file"],
)
else:
vocab_file = (
filename_prefix + "-" if filename_prefix else ""
) + save_directory
with open(vocab_file, "w", encoding="utf-8") as writer:
for token, token_index in sorted(self.vocab.items(), key=lambda kv: kv[1]):
if index != token_index:
# logger.warning(
# f"Saving vocabulary to {vocab_file}: vocabulary indices are not consecutive."
# " Please check that the vocabulary is not corrupted!"
# )
index = token_index
writer.write(token + "\n")
index += 1
return (vocab_file,)
# Copied from transformers.models.bert.tokenization_bert.BasicTokenizer
class BasicTokenizer(object):
"""
Constructs a BasicTokenizer that will run basic tokenization (punctuation splitting, lower casing, etc.).
Args:
do_lower_case (`bool`, *optional*, defaults to `True`):
Whether or not to lowercase the input when tokenizing.
never_split (`Iterable`, *optional*):
Collection of tokens which will never be split during tokenization. Only has an effect when
`do_basic_tokenize=True`
tokenize_chinese_chars (`bool`, *optional*, defaults to `True`):
Whether or not to tokenize Chinese characters.
This should likely be deactivated for Japanese (see this
[issue](https://github.com/huggingface/transformers/issues/328)).
strip_accents (`bool`, *optional*):
Whether or not to strip all accents. If this option is not specified, then it will be determined by the
value for `lowercase` (as in the original BERT).
do_split_on_punc (`bool`, *optional*, defaults to `True`):
In some instances we want to skip the basic punctuation splitting so that later tokenization can capture
the full context of the words, such as contractions.
"""
def __init__(
self,
do_lower_case=True,
never_split=None,
tokenize_chinese_chars=True,
strip_accents=None,
do_split_on_punc=True,
):
if never_split is None:
never_split = []
self.do_lower_case = do_lower_case
self.never_split = set(never_split)
self.tokenize_chinese_chars = tokenize_chinese_chars
self.strip_accents = strip_accents
self.do_split_on_punc = do_split_on_punc
def tokenize(self, text, never_split=None):
"""
Basic Tokenization of a piece of text. For sub-word tokenization, see WordPieceTokenizer.
Args:
never_split (`List[str]`, *optional*)
Kept for backward compatibility purposes. Now implemented directly at the base class level (see
[`PreTrainedTokenizer.tokenize`]) List of token not to split.
"""
# union() returns a new set by concatenating the two sets.
never_split = (
self.never_split.union(set(never_split))
if never_split
else self.never_split
)
text = self._clean_text(text)
# This was added on November 1st, 2018 for the multilingual and Chinese
# models. This is also applied to the English models now, but it doesn't
# matter since the English models were not trained on any Chinese data
# and generally don't have any Chinese data in them (there are Chinese
# characters in the vocabulary because Wikipedia does have some Chinese
# words in the English Wikipedia.).
if self.tokenize_chinese_chars:
text = self._tokenize_chinese_chars(text)
# prevents treating the same character with different unicode codepoints as different characters
unicode_normalized_text = unicodedata.normalize("NFC", text)
orig_tokens = whitespace_tokenize(unicode_normalized_text)
split_tokens = []
for token in orig_tokens:
if token not in never_split:
if self.do_lower_case:
token = token.lower()
if self.strip_accents is not False:
token = self._run_strip_accents(token)
elif self.strip_accents:
token = self._run_strip_accents(token)
split_tokens.extend(self._run_split_on_punc(token, never_split))
output_tokens = whitespace_tokenize(" ".join(split_tokens))
return output_tokens
def _run_strip_accents(self, text):
"""Strips accents from a piece of text."""
text = unicodedata.normalize("NFD", text)
output = []
for char in text:
cat = unicodedata.category(char)
if cat == "Mn":
continue
output.append(char)
return "".join(output)
def _run_split_on_punc(self, text, never_split=None):
"""Splits punctuation on a piece of text."""
if not self.do_split_on_punc or (
never_split is not None and text in never_split
):
return [text]
chars = list(text)
i = 0
start_new_word = True
output = []
while i < len(chars):
char = chars[i]
if _is_punctuation(char):
output.append([char])
start_new_word = True
else:
if start_new_word:
output.append([])
start_new_word = False
output[-1].append(char)
i += 1
return ["".join(x) for x in output]
def _tokenize_chinese_chars(self, text):
"""Adds whitespace around any CJK character."""
output = []
for char in text:
cp = ord(char)
if self._is_chinese_char(cp):
output.append(" ")
output.append(char)
output.append(" ")
else:
output.append(char)
return "".join(output)
def _is_chinese_char(self, cp):
"""Checks whether CP is the codepoint of a CJK character."""
# This defines a "chinese character" as anything in the CJK Unicode block:
# https://en.wikipedia.org/wiki/CJK_Unified_Ideographs_(Unicode_block)
#
# Note that the CJK Unicode block is NOT all Japanese and Korean characters,
# despite its name. The modern Korean Hangul alphabet is a different block,
# as is Japanese Hiragana and Katakana. Those alphabets are used to write
# space-separated words, so they are not treated specially and handled
# like the all of the other languages.
if (
(cp >= 0x4E00 and cp <= 0x9FFF)
or (cp >= 0x3400 and cp <= 0x4DBF) #
or (cp >= 0x20000 and cp <= 0x2A6DF) #
or (cp >= 0x2A700 and cp <= 0x2B73F) #
or (cp >= 0x2B740 and cp <= 0x2B81F) #
or (cp >= 0x2B820 and cp <= 0x2CEAF) #
or (cp >= 0xF900 and cp <= 0xFAFF)
or (cp >= 0x2F800 and cp <= 0x2FA1F) #
): #
return True
return False
def _clean_text(self, text):
"""Performs invalid character removal and whitespace cleanup on text."""
output = []
for char in text:
cp = ord(char)
if cp == 0 or cp == 0xFFFD or _is_control(char):
continue
if _is_whitespace(char):
output.append(" ")
else:
output.append(char)
return "".join(output)
# Copied from transformers.models.bert.tokenization_bert.WordpieceTokenizer
class WordpieceTokenizer(object):
"""Runs WordPiece tokenization."""
def __init__(self, vocab, unk_token, max_input_chars_per_word=100):
self.vocab = vocab
self.unk_token = unk_token
self.max_input_chars_per_word = max_input_chars_per_word
def tokenize(self, text):
"""
Tokenizes a piece of text into its word pieces. This uses a greedy longest-match-first algorithm to perform
tokenization using the given vocabulary.
For example, `input = "unaffable"` wil return as output `["un", "##aff", "##able"]`.
Args:
text: A single token or whitespace separated tokens. This should have
already been passed through *BasicTokenizer*.
Returns:
A list of wordpiece tokens.
"""
output_tokens = []
for token in whitespace_tokenize(text):
chars = list(token)
if len(chars) > self.max_input_chars_per_word:
output_tokens.append(self.unk_token)
continue
is_bad = False
start = 0
sub_tokens = []
while start < len(chars):
end = len(chars)
cur_substr = None
while start < end:
substr = "".join(chars[start:end])
if start > 0:
substr = "##" + substr
if substr in self.vocab:
cur_substr = substr
break
end -= 1
if cur_substr is None:
is_bad = True
break
sub_tokens.append(cur_substr)
start = end
if is_bad:
output_tokens.append(self.unk_token)
else:
output_tokens.extend(sub_tokens)
return output_tokens