Add BERT classifier example

This commit is contained in:
Thiago Crepaldi 2020-11-02 16:19:12 -08:00
parent 30042b6e0e
commit 3b267d1d60
2 changed files with 379 additions and 1 deletions

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@ -49,6 +49,10 @@ class ORTModule(torch.nn.Module):
# Log level
self._loglevel = getattr(logging, 'WARNING')
# TODO: debug flags
self._save_onnx = False
self._save_onnx_prefix = ''
def forward(self, *inputs, **kwargs):
'''Forward pass starts here and continues at `_ORTModuleFunction.forward`
@ -65,6 +69,13 @@ class ORTModule(torch.nn.Module):
self._onnx_training = ORTModule._get_forward_graph(self._original_module, *inputs, **kwargs)
self._onnx_gradient = ORTModule._build_gradient_graph(self._onnx_training, self._grad_builder_config)
self._onnx_forward, self._onnx_backward = ORTModule._split_forward_and_backward(self._onnx_gradient, self._grad_builder_config.weight_names_to_train)
if self._save_onnx:
onnx.save(self._onnx_training, self._save_onnx_prefix + '_full_training.onnx')
onnx.save(self._onnx_gradient, self._save_onnx_prefix + '_with_grad.onnx')
onnx.save(self._onnx_forward, self._save_onnx_prefix + '_forward.onnx')
onnx.save(self._onnx_backward, self._save_onnx_prefix + '_backward.onnx')
# TODO: hard-coding to CPU only
self._forward_session = onnxruntime.InferenceSession(self._onnx_forward.SerializeToString(), providers=['CPUExecutionProvider'])
self._backward_session = onnxruntime.InferenceSession(self._onnx_backward.SerializeToString(), providers=['CPUExecutionProvider'])
@ -319,7 +330,6 @@ class ORTModule(torch.nn.Module):
def _get_forward_graph(module, *inputs, **kwargs):
'''Exports PyTorch `module` to ONNX with training flag, using `*inputs` as input
TODO: Support contrib OPs support? user model has no hint
TODO: How to support dynamic axes? Dimensions are determined by samples
TODO: How to ingest **kwargs in proper order during export?
'''
@ -329,6 +339,10 @@ class ORTModule(torch.nn.Module):
# Deepcopy inputs, since input values may change after model run.
sample_inputs_copy = copy.deepcopy(inputs)
# TODO: Support contrib OPs support? user model has no hint
# from onnxruntime.training import register_custom_ops_pytorch_exporter
# register_custom_ops_pytorch_exporter.register_custom_op()
# Export torch.nn.Module to ONNX
torch.onnx.export(module,
tuple(sample_inputs_copy),

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@ -0,0 +1,364 @@
import torch
import wget
import os
import pandas as pd
import zipfile
from transformers import BertTokenizer
from keras.preprocessing.sequence import pad_sequences
from sklearn.model_selection import train_test_split
from torch.utils.data import TensorDataset, DataLoader, RandomSampler, SequentialSampler
from transformers import BertForSequenceClassification, AdamW, BertConfig
from transformers import get_linear_schedule_with_warmup
import numpy as np
import random
import time
import datetime
import onnxruntime
from onnxruntime.training import ORTModule
# 1. Device setup
# TODO: Hard-coding for CPU for ORTModule
# if torch.cuda.is_available():
# device = torch.device("cuda")
# print('There are %d GPU(s) available.' % torch.cuda.device_count())
# print('We will use the GPU:', torch.cuda.get_device_name(0))
# else:
# print('No GPU available, using the CPU instead.')
# device = torch.device("cpu")
device = torch.device("cpu")
# 2. Loading CoLA Dataset
print('Downloading dataset...')
url = 'https://nyu-mll.github.io/CoLA/cola_public_1.1.zip'
# Download the file (if we haven't already)
if not os.path.exists('./cola_public_1.1.zip'):
wget.download(url, './cola_public_1.1.zip')
else:
print('Reusing cached dataset')
# Unzip it
if not os.path.exists('./cola_public'):
print('Extracting cached dataset')
with zipfile.ZipFile('./cola_public_1.1.zip', 'r') as zip_ref:
zip_ref.extractall('./')
else:
print('Reusing extracted dataset')
# Load the dataset into a pandas dataframe.
df = pd.read_csv("./cola_public/raw/in_domain_train.tsv", delimiter='\t', header=None, names=['sentence_source', 'label', 'label_notes', 'sentence'])
# Get the lists of sentences and their labels.
sentences = df.sentence.values
labels = df.label.values
# 3. Tokenization & Input Formatting
# Load the BERT tokenizer.
tokenizer = BertTokenizer.from_pretrained('bert-base-uncased', do_lower_case=True)
# Tokenize all of the sentences and map the tokens to their word IDs.
input_ids = []
for sent in sentences:
# `encode` will:
# (1) Tokenize the sentence.
# (2) Prepend the `[CLS]` token to the start.
# (3) Append the `[SEP]` token to the end.
# (4) Map tokens to their IDs.
encoded_sent = tokenizer.encode(
sent, # Sentence to encode.
add_special_tokens = True, # Add '[CLS]' and '[SEP]'
)
# Add the encoded sentence to the list.
input_ids.append(encoded_sent)
# We'll borrow the `pad_sequences` utility function to do this.
# 64 is slightly larger than the maximum training sentence length of 47...
MAX_LEN = 64
# Pad our input tokens with value 0.
input_ids = pad_sequences(input_ids, maxlen=MAX_LEN, dtype="long",
value=0, truncating="post", padding="post")
# Create attention masks
attention_masks = []
# For each sentence...
for sent in input_ids:
# Create the attention mask.
# - If a token ID is 0, then it's padding, set the mask to 0.
# - If a token ID is > 0, then it's a real token, set the mask to 1.
att_mask = [int(token_id > 0) for token_id in sent]
# Store the attention mask for this sentence.
attention_masks.append(att_mask)
# Use 90% for training and 10% for validation.
train_inputs, validation_inputs, train_labels, validation_labels = train_test_split(input_ids, labels,
random_state=2018, test_size=0.1)
# Do the same for the masks.
train_masks, validation_masks, _, _ = train_test_split(attention_masks, labels,
random_state=2018, test_size=0.1)
# Convert all inputs and labels into torch tensors, the required datatype
# for our model.
train_inputs = torch.tensor(train_inputs)
validation_inputs = torch.tensor(validation_inputs)
train_labels = torch.tensor(train_labels)
validation_labels = torch.tensor(validation_labels)
train_masks = torch.tensor(train_masks)
validation_masks = torch.tensor(validation_masks)
# The DataLoader needs to know our batch size for training, so we specify it
batch_size = 32
# Create the DataLoader for our training set.
train_data = TensorDataset(train_inputs, train_masks, train_labels)
train_sampler = RandomSampler(train_data)
train_dataloader = DataLoader(train_data, sampler=train_sampler, batch_size=batch_size)
# Create the DataLoader for our validation set.
validation_data = TensorDataset(validation_inputs, validation_masks, validation_labels)
validation_sampler = SequentialSampler(validation_data)
validation_dataloader = DataLoader(validation_data, sampler=validation_sampler, batch_size=batch_size)
# 4. Train (fine-tune)
# TODO: try to use a smaller model
# Load BertForSequenceClassification, the pretrained BERT model with a single
# linear classification layer on top.
model = BertForSequenceClassification.from_pretrained(
"bert-base-uncased", # Use the 12-layer BERT model, with an uncased vocab.
# '/home/thiagofc/dev/github/onnxruntime/orttraining/orttraining/test/python/',
num_labels = 2, # The number of output labels--2 for binary classification.
output_attentions = False, # Whether the model returns attentions weights.
output_hidden_states = False, # Whether the model returns all hidden-states.
)
model = ORTModule(model)
# TODO: change it to False to stop saving ONNX models
model._save_onnx = True
model._save_onnx_prefix = 'BertForSequenceClassification'
# Tell pytorch to run this model on the GPU.
# TODO: Hard coding it to CPU for ORTModule
# model.cuda()
# Note: AdamW is a class from the huggingface library (as opposed to pytorch)
optimizer = AdamW(model.parameters(),
lr = 2e-5, # args.learning_rate - default is 5e-5, our notebook had 2e-5
eps = 1e-8 # args.adam_epsilon - default is 1e-8.
)
# Number of training epochs (authors recommend between 2 and 4)
epochs = 4
# Total number of training steps is number of batches * number of epochs.
total_steps = len(train_dataloader) * epochs
# Create the learning rate scheduler.
scheduler = get_linear_schedule_with_warmup(optimizer,
num_warmup_steps = 0, # Default value in run_glue.py
num_training_steps = total_steps)
# Function to calculate the accuracy of our predictions vs labels
def flat_accuracy(preds, labels):
pred_flat = np.argmax(preds, axis=1).flatten()
labels_flat = labels.flatten()
return np.sum(pred_flat == labels_flat) / len(labels_flat)
def format_time(elapsed):
'''Takes a time in seconds and returns a string hh:mm:ss'''
# Round to the nearest second.
elapsed_rounded = int(round((elapsed)))
# Format as hh:mm:ss
return str(datetime.timedelta(seconds=elapsed_rounded))
# This training code is based on the `run_glue.py` script here:
# https://github.com/huggingface/transformers/blob/5bfcd0485ece086ebcbed2d008813037968a9e58/examples/run_glue.py#L128
# Set the seed value all over the place to make this reproducible.
seed_val = 42
random.seed(seed_val)
np.random.seed(seed_val)
torch.manual_seed(seed_val)
onnxruntime.set_seed(seed_val)
# TODO: We are not using CUDA for ORTModule just yet
# torch.cuda.manual_seed_all(seed_val)
# Store the average loss after each epoch so we can plot them.
loss_values = []
# ========================================
# Training
# ========================================
for epoch_i in range(0, epochs):
# Perform one full pass over the training set.
print("")
print('======== Epoch {:} / {:} ========'.format(epoch_i + 1, epochs))
# Measure how long the training epoch takes.
t0 = time.time()
# Reset the total loss for this epoch.
total_loss = 0
# Put the model into training mode. Don't be mislead--the call to
# `train` just changes the *mode*, it doesn't *perform* the training.
# `dropout` and `batchnorm` layers behave differently during training
# vs. test (source: https://stackoverflow.com/questions/51433378/what-does-model-train-do-in-pytorch)
model.train()
# For each batch of training data...
for step, batch in enumerate(train_dataloader):
# Progress update every 40 batches.
if step % 40 == 0 and not step == 0:
# Calculate elapsed time in minutes.
elapsed = format_time(time.time() - t0)
# Report progress.
print(' Batch {:>5,} of {:>5,}. Elapsed: {:}.'.format(step, len(train_dataloader), elapsed))
# Unpack this training batch from our dataloader.
#
# As we unpack the batch, we'll also copy each tensor to the GPU using the
# `to` method.
#
# `batch` contains three pytorch tensors:
# [0]: input ids
# [1]: attention masks
# [2]: labels
b_input_ids = batch[0].to(device)
b_input_mask = batch[1].to(device)
b_labels = batch[2].to(device)
# Always clear any previously calculated gradients before performing a
# backward pass. PyTorch doesn't do this automatically because
# accumulating the gradients is "convenient while training RNNs".
# (source: https://stackoverflow.com/questions/48001598/why-do-we-need-to-call-zero-grad-in-pytorch)
model.zero_grad()
# Perform a forward pass (evaluate the model on this training batch).
# This will return the loss (rather than the model output) because we
# have provided the `labels`.
# The documentation for this `model` function is here:
# https://huggingface.co/transformers/v2.2.0/model_doc/bert.html#transformers.BertForSequenceClassification
outputs = model(b_input_ids,
token_type_ids=None,
attention_mask=b_input_mask,
labels=b_labels)
# The call to `model` always returns a tuple, so we need to pull the
# loss value out of the tuple.
loss = outputs[0]
# Accumulate the training loss over all of the batches so that we can
# calculate the average loss at the end. `loss` is a Tensor containing a
# single value; the `.item()` function just returns the Python value
# from the tensor.
total_loss += loss.item()
# total_loss += loss
# Perform a backward pass to calculate the gradients.
print(loss)
loss.backward()
# Clip the norm of the gradients to 1.0.
# This is to help prevent the "exploding gradients" problem.
torch.nn.utils.clip_grad_norm_(model.parameters(), 1.0)
# Update parameters and take a step using the computed gradient.
# The optimizer dictates the "update rule"--how the parameters are
# modified based on their gradients, the learning rate, etc.
optimizer.step()
# Update the learning rate.
scheduler.step()
# Calculate the average loss over the training data.
avg_train_loss = total_loss / len(train_dataloader)
# Store the loss value for plotting the learning curve.
loss_values.append(avg_train_loss)
print("")
print(" Average training loss: {0:.2f}".format(avg_train_loss))
print(" Training epoch took: {:}".format(format_time(time.time() - t0)))
# ========================================
# Validation
# ========================================
# After the completion of each training epoch, measure our performance on
# our validation set.
print("")
print("Running Validation...")
t0 = time.time()
# Put the model in evaluation mode--the dropout layers behave differently
# during evaluation.
model.eval()
# Tracking variables
eval_loss, eval_accuracy = 0, 0
nb_eval_steps, nb_eval_examples = 0, 0
# Evaluate data for one epoch
for batch in validation_dataloader:
# Add batch to GPU
batch = tuple(t.to(device) for t in batch)
# Unpack the inputs from our dataloader
b_input_ids, b_input_mask, b_labels = batch
# Telling the model not to compute or store gradients, saving memory and
# speeding up validation
with torch.no_grad():
# Forward pass, calculate logit predictions.
# This will return the logits rather than the loss because we have
# not provided labels.
# token_type_ids is the same as the "segment ids", which
# differentiates sentence 1 and 2 in 2-sentence tasks.
# The documentation for this `model` function is here:
# https://huggingface.co/transformers/v2.2.0/model_doc/bert.html#transformers.BertForSequenceClassification
outputs = model(b_input_ids,
token_type_ids=None,
attention_mask=b_input_mask)
# Get the "logits" output by the model. The "logits" are the output
# values prior to applying an activation function like the softmax.
logits = outputs[0]
# Move logits and labels to CPU
logits = logits.detach().cpu().numpy()
label_ids = b_labels.to('cpu').numpy()
# Calculate the accuracy for this batch of test sentences.
tmp_eval_accuracy = flat_accuracy(logits, label_ids)
# Accumulate the total accuracy.
eval_accuracy += tmp_eval_accuracy
# Track the number of batches
nb_eval_steps += 1
# Report the final accuracy for this validation run.
print(" Accuracy: {0:.2f}".format(eval_accuracy/nb_eval_steps))
print(" Validation took: {:}".format(format_time(time.time() - t0)))
print("")
print("Training complete!")