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textattack-nlp-transformer/textattack/shared/utils/tensor.py

106 lines
3.6 KiB
Python

import torch
import textattack
from textattack.shared import utils
def batch_tokenize(tokenizer, attacked_text_list):
""" Tokenizes a list of inputs and returns their tokenized forms in a list. """
inputs = [at.text for at in attacked_text_list]
if hasattr(tokenizer, "encode_batch"):
return tokenizer.encode_batch(inputs)
else:
return [tokenizer.encode(x) for x in inputs]
def batch_model_predict(model, inputs, batch_size=utils.config("MODEL_BATCH_SIZE")):
outputs = []
i = 0
while i < len(inputs):
batch = inputs[i : i + batch_size]
batch_preds = model_predict(model, batch)
outputs.append(batch_preds)
i += batch_size
try:
return torch.cat(outputs, dim=0)
except TypeError:
# A TypeError occurs when the lists in ``outputs`` are full of strings
# instead of numbers. If this is the case, just return the regular
# list.
return outputs
def get_model_device(model):
if hasattr(model, "model"):
model_device = next(model.model.parameters()).device
else:
model_device = next(model.parameters()).device
return model_device
def model_predict(model, inputs):
try:
return try_model_predict(model, inputs)
except Exception as e:
textattack.shared.utils.logger.error(
f"Failed to predict with model {model}. Check tokenizer configuration."
)
raise e
def try_model_predict(model, inputs):
model_device = get_model_device(model)
if isinstance(inputs[0], dict):
# If ``inputs`` is a list of dicts, we convert them to a single dict
# (now of tensors) and pass to the model as kwargs.
# Convert list of dicts to dict of lists.
input_dict = {k: [_dict[k] for _dict in inputs] for k in inputs[0]}
# Convert list keys to tensors.
for key in input_dict:
input_dict[key] = pad_lists(input_dict[key])
input_dict[key] = torch.tensor(input_dict[key]).to(model_device)
# Do inference using keys as kwargs.
outputs = model(**input_dict)
else:
# If ``inputs`` is not a list of dicts, it's either a list of tuples
# (model takes multiple inputs) or a list of ID lists (where the model
# takes a single input). In this case, we'll do our best to figure out
# the proper input to the model, anyway.
input_dim = get_list_dim(inputs)
if input_dim == 2:
# For models where the input is a single vector.
inputs = pad_lists(inputs)
inputs = torch.tensor(inputs).to(model_device)
outputs = model(inputs)
elif input_dim == 3:
# For models that take multiple vectors per input.
inputs = map(list, zip(*inputs))
inputs = map(pad_lists, inputs)
inputs = (torch.tensor(x).to(model_device) for x in inputs)
outputs = model(*inputs)
else:
raise TypeError(f"Error: malformed inputs.ndim ({input_dim})")
# If `outputs` is a tuple, take the first argument.
if isinstance(outputs, tuple):
outputs = outputs[0]
return outputs
def get_list_dim(ids):
if isinstance(ids, tuple) or isinstance(ids, list) or isinstance(ids, torch.Tensor):
return 1 + get_list_dim(ids[0])
else:
return 0
def pad_lists(lists, pad_token=0):
""" Pads lists with trailing zeros to make them all the same length. """
max_list_len = max(len(l) for l in lists)
for i in range(len(lists)):
lists[i] += [pad_token] * (max_list_len - len(lists[i]))
return lists