torch.no_grad vs. requires_grad

1 files changed, 850 insertions, 0 deletions

diff --git a/fine_tune/bert/bert_fine_tune.ipynb b/fine_tune/bert/bert_fine_tune.ipynb
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+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T08:55:39.339410Z",
+     "start_time": "2022-06-25T08:55:38.522277Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "import os\n",
+    "import re\n",
+    "from tqdm import tqdm\n",
+    "import numpy as np\n",
+    "import pandas as pd\n",
+    "import matplotlib.pyplot as plt\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T08:55:45.550205Z",
+     "start_time": "2022-06-25T08:55:45.521302Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    " # Load data and set labels\n",
+    "data_complaint = pd.read_csv('data/complaint1700.csv')\n",
+    "data_complaint['label'] = 0\n",
+    "data_non_complaint = pd.read_csv('data/noncomplaint1700.csv')\n",
+    "data_non_complaint['label'] = 1\n",
+    "\n",
+    "# Concatenate complaining and non-complaining data\n",
+    "data = pd.concat([data_complaint, data_non_complaint], axis=0).reset_index(drop=True)\n",
+    "\n",
+    "# Drop 'airline' column\n",
+    "data.drop(['airline'], inplace=True, axis=1)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T08:55:53.310710Z",
+     "start_time": "2022-06-25T08:55:53.295841Z"
+    }
+   },
+   "outputs": [
+    {
+     "data": {
+      "text/html": [
+       "<div>\n",
+       "<style scoped>\n",
+       "    .dataframe tbody tr th:only-of-type {\n",
+       "        vertical-align: middle;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe tbody tr th {\n",
+       "        vertical-align: top;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe thead th {\n",
+       "        text-align: right;\n",
+       "    }\n",
+       "</style>\n",
+       "<table border=\"1\" class=\"dataframe\">\n",
+       "  <thead>\n",
+       "    <tr style=\"text-align: right;\">\n",
+       "      <th></th>\n",
+       "      <th>id</th>\n",
+       "      <th>tweet</th>\n",
+       "      <th>label</th>\n",
+       "    </tr>\n",
+       "  </thead>\n",
+       "  <tbody>\n",
+       "    <tr>\n",
+       "      <th>2579</th>\n",
+       "      <td>82091</td>\n",
+       "      <td>@AlaskaAir @RSherman_25 Thank you so much!! Ca...</td>\n",
+       "      <td>1</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>657</th>\n",
+       "      <td>147575</td>\n",
+       "      <td>@DeltaAssist hi. I lost my sunglasses on a fli...</td>\n",
+       "      <td>0</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>1971</th>\n",
+       "      <td>23890</td>\n",
+       "      <td>Flights to #PuertoRico booked on @JetBlue! Can...</td>\n",
+       "      <td>1</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>3312</th>\n",
+       "      <td>160070</td>\n",
+       "      <td>@united Do you offer open-ended tickets? CLT-B...</td>\n",
+       "      <td>1</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>1034</th>\n",
+       "      <td>63946</td>\n",
+       "      <td>So @AmericanAir I'm going to need you all to g...</td>\n",
+       "      <td>0</td>\n",
+       "    </tr>\n",
+       "  </tbody>\n",
+       "</table>\n",
+       "</div>"
+      ],
+      "text/plain": [
+       "          id                                              tweet  label\n",
+       "2579   82091  @AlaskaAir @RSherman_25 Thank you so much!! Ca...      1\n",
+       "657   147575  @DeltaAssist hi. I lost my sunglasses on a fli...      0\n",
+       "1971   23890  Flights to #PuertoRico booked on @JetBlue! Can...      1\n",
+       "3312  160070  @united Do you offer open-ended tickets? CLT-B...      1\n",
+       "1034   63946  So @AmericanAir I'm going to need you all to g...      0"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "data.sample(5)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T08:56:10.130909Z",
+     "start_time": "2022-06-25T08:56:08.960476Z"
+    }
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "No GPU available, using the CPU instead.\n"
+     ]
+    }
+   ],
+   "source": [
+    "import torch\n",
+    "\n",
+    "if torch.cuda.is_available():       \n",
+    "    device = torch.device(\"cuda\")\n",
+    "    print(f'There are {torch.cuda.device_count()} GPU(s) available.')\n",
+    "    print('Device name:', torch.cuda.get_device_name(0))\n",
+    "\n",
+    "else:\n",
+    "    print('No GPU available, using the CPU instead.')\n",
+    "    device = torch.device(\"cpu\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T08:56:37.054745Z",
+     "start_time": "2022-06-25T08:56:37.051239Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "def text_preprocessing(text):\n",
+    "    \"\"\"\n",
+    "    - Remove entity mentions (eg. '@united')\n",
+    "    - Correct errors (eg. '&amp;' to '&')\n",
+    "    @param    text (str): a string to be processed.\n",
+    "    @return   text (Str): the processed string.\n",
+    "    \"\"\"\n",
+    "    # Remove '@name'\n",
+    "    text = re.sub(r'(@.*?)[\\s]', ' ', text)\n",
+    "\n",
+    "    # Replace '&amp;' with '&'\n",
+    "    text = re.sub(r'&amp;', '&', text)\n",
+    "\n",
+    "    # Remove trailing whitespace\n",
+    "    text = re.sub(r'\\s+', ' ', text).strip()\n",
+    "\n",
+    "    return text"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T08:57:01.039579Z",
+     "start_time": "2022-06-25T08:57:00.483491Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "from sklearn.model_selection import train_test_split\n",
+    "\n",
+    "X = data.tweet.values\n",
+    "y = data.label.values\n",
+    "\n",
+    "X_train, X_val, y_train, y_val =\\\n",
+    "    train_test_split(X, y, test_size=0.1, random_state=2020)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T08:59:17.779189Z",
+     "start_time": "2022-06-25T08:59:17.759147Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "# Load test data\n",
+    "test_data = pd.read_csv('data/test_data.csv')\n",
+    "\n",
+    "# Keep important columns\n",
+    "test_data = test_data[['id', 'tweet']]\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:00:01.125406Z",
+     "start_time": "2022-06-25T08:59:48.736061Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "from transformers import BertTokenizer\n",
+    "\n",
+    "# Load the BERT tokenizer\n",
+    "tokenizer = BertTokenizer.from_pretrained('bert-base-uncased', do_lower_case=True)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:00:06.381689Z",
+     "start_time": "2022-06-25T09:00:01.928757Z"
+    }
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Max length:  68\n"
+     ]
+    }
+   ],
+   "source": [
+    "# Concatenate train data and test data\n",
+    "all_tweets = np.concatenate([data.tweet.values, test_data.tweet.values])\n",
+    "\n",
+    "# Encode our concatenated data\n",
+    "encoded_tweets = [tokenizer.encode(sent, add_special_tokens=True) for sent in all_tweets]\n",
+    "\n",
+    "# Find the maximum length\n",
+    "max_len = max([len(sent) for sent in encoded_tweets])\n",
+    "print('Max length: ', max_len)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:00:18.264259Z",
+     "start_time": "2022-06-25T09:00:18.261607Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "max_len = 64"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:00:34.288131Z",
+     "start_time": "2022-06-25T09:00:34.282880Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "# Create a function to tokenize a set of texts\n",
+    "def preprocessing_for_bert(data):\n",
+    "    \"\"\"Perform required preprocessing steps for pretrained BERT.\n",
+    "    @param    data (np.array): Array of texts to be processed.\n",
+    "    @return   input_ids (torch.Tensor): Tensor of token ids to be fed to a model.\n",
+    "    @return   attention_masks (torch.Tensor): Tensor of indices specifying which\n",
+    "                  tokens should be attended to by the model.\n",
+    "    \"\"\"\n",
+    "    # Create empty lists to store outputs\n",
+    "    input_ids = []\n",
+    "    attention_masks = []\n",
+    "\n",
+    "    # For every sentence...\n",
+    "    for sent in data:\n",
+    "        # `encode_plus` will:\n",
+    "        #    (1) Tokenize the sentence\n",
+    "        #    (2) Add the `[CLS]` and `[SEP]` token to the start and end\n",
+    "        #    (3) Truncate/Pad sentence to max length\n",
+    "        #    (4) Map tokens to their IDs\n",
+    "        #    (5) Create attention mask\n",
+    "        #    (6) Return a dictionary of outputs\n",
+    "        encoded_sent = tokenizer.encode_plus(\n",
+    "            text=text_preprocessing(sent),  # Preprocess sentence\n",
+    "            add_special_tokens=True,        # Add `[CLS]` and `[SEP]`\n",
+    "            max_length = max_len,                  # Max length to truncate/pad\n",
+    "            pad_to_max_length=True,         # Pad sentence to max length\n",
+    "            #return_tensors='pt',           # Return PyTorch tensor\n",
+    "            return_attention_mask=True      # Return attention mask\n",
+    "            )\n",
+    "        \n",
+    "        # Add the outputs to the lists\n",
+    "        input_ids.append(encoded_sent.get('input_ids'))\n",
+    "        attention_masks.append(encoded_sent.get('attention_mask'))\n",
+    "\n",
+    "    # Convert lists to tensors\n",
+    "    input_ids = torch.tensor(input_ids)\n",
+    "    attention_masks = torch.tensor(attention_masks)\n",
+    "\n",
+    "    return input_ids, attention_masks"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:00:52.948339Z",
+     "start_time": "2022-06-25T09:00:51.094279Z"
+    }
+   },
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "Truncation was not explicitly activated but `max_length` is provided a specific value, please use `truncation=True` to explicitly truncate examples to max length. Defaulting to 'longest_first' truncation strategy. If you encode pairs of sequences (GLUE-style) with the tokenizer you can select this strategy more precisely by providing a specific strategy to `truncation`.\n",
+      "/Users/chunhuizhang/anaconda3/lib/python3.6/site-packages/transformers/tokenization_utils_base.py:2217: FutureWarning: The `pad_to_max_length` argument is deprecated and will be removed in a future version, use `padding=True` or `padding='longest'` to pad to the longest sequence in the batch, or use `padding='max_length'` to pad to a max length. In this case, you can give a specific length with `max_length` (e.g. `max_length=45`) or leave max_length to None to pad to the maximal input size of the model (e.g. 512 for Bert).\n",
+      "  FutureWarning,\n"
+     ]
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Original:  @united I'm having issues. Yesterday I rebooked for 24 hours after I was supposed to fly, now I can't log on &amp; check in. Can you help?\n",
+      "Token IDs:  [101, 1045, 1005, 1049, 2383, 3314, 1012, 7483, 1045, 2128, 8654, 2098, 2005, 2484, 2847, 2044, 1045, 2001, 4011, 2000, 4875, 1010, 2085, 1045, 2064, 1005, 1056, 8833, 2006, 1004, 4638, 1999, 1012, 2064, 2017, 2393, 1029, 102, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]\n",
+      "Tokenizing data...\n"
+     ]
+    }
+   ],
+   "source": [
+    "# Print sentence 0 and its encoded token ids\n",
+    "token_ids = list(preprocessing_for_bert([X[0]])[0].squeeze().numpy())\n",
+    "print('Original: ', X[0])\n",
+    "print('Token IDs: ', token_ids)\n",
+    "\n",
+    "# Run function `preprocessing_for_bert` on the train set and the validation set\n",
+    "print('Tokenizing data...')\n",
+    "train_inputs, train_masks = preprocessing_for_bert(X_train)\n",
+    "val_inputs, val_masks = preprocessing_for_bert(X_val)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:01:08.103694Z",
+     "start_time": "2022-06-25T09:01:08.088666Z"
+    }
+   },
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "tensor([[  101,  2054,  1005,  ...,     0,     0,     0],\n",
+       "        [  101,  2054,  1996,  ...,     0,     0,     0],\n",
+       "        [  101,  3524,  2054,  ...,     0,     0,     0],\n",
+       "        ...,\n",
+       "        [  101,  3294, 17203,  ...,     0,     0,     0],\n",
+       "        [  101,  1045,  5223,  ...,     0,     0,     0],\n",
+       "        [  101,  1998,  2009,  ...,     0,     0,     0]])"
+      ]
+     },
+     "execution_count": 18,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "train_inputs"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:01:14.520761Z",
+     "start_time": "2022-06-25T09:01:14.516264Z"
+    }
+   },
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "tensor([[1, 1, 1,  ..., 0, 0, 0],\n",
+       "        [1, 1, 1,  ..., 0, 0, 0],\n",
+       "        [1, 1, 1,  ..., 0, 0, 0],\n",
+       "        ...,\n",
+       "        [1, 1, 1,  ..., 0, 0, 0],\n",
+       "        [1, 1, 1,  ..., 0, 0, 0],\n",
+       "        [1, 1, 1,  ..., 0, 0, 0]])"
+      ]
+     },
+     "execution_count": 19,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "train_masks"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:01:26.298148Z",
+     "start_time": "2022-06-25T09:01:26.291846Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "from torch.utils.data import TensorDataset, DataLoader, RandomSampler, SequentialSampler\n",
+    "\n",
+    "# Convert other data types to torch.Tensor\n",
+    "train_labels = torch.tensor(y_train)\n",
+    "val_labels = torch.tensor(y_val)\n",
+    "\n",
+    "# For fine-tuning BERT, the authors recommend a batch size of 16 or 32.\n",
+    "batch_size = 32\n",
+    "\n",
+    "# Create the DataLoader for our training set\n",
+    "train_data = TensorDataset(train_inputs, train_masks, train_labels)\n",
+    "train_sampler = RandomSampler(train_data)\n",
+    "train_dataloader = DataLoader(train_data, sampler=train_sampler, batch_size=batch_size)\n",
+    "\n",
+    "# Create the DataLoader for our validation set\n",
+    "val_data = TensorDataset(val_inputs, val_masks, val_labels)\n",
+    "val_sampler = SequentialSampler(val_data)\n",
+    "val_dataloader = DataLoader(val_data, sampler=val_sampler, batch_size=batch_size)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:01:39.358697Z",
+     "start_time": "2022-06-25T09:01:39.336610Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "import torch\n",
+    "import torch.nn as nn\n",
+    "from transformers import BertModel\n",
+    "\n",
+    "# Create the BertClassfier class\n",
+    "class BertClassifier(nn.Module):\n",
+    "    \"\"\"Bert Model for Classification Tasks.\n",
+    "    \"\"\"\n",
+    "    def __init__(self, freeze_bert=False):\n",
+    "        \"\"\"\n",
+    "        @param    bert: a BertModel object\n",
+    "        @param    classifier: a torch.nn.Module classifier\n",
+    "        @param    freeze_bert (bool): Set `False` to fine-tune the BERT model\n",
+    "        \"\"\"\n",
+    "        super(BertClassifier, self).__init__()\n",
+    "        # Specify hidden size of BERT, hidden size of our classifier, and number of labels\n",
+    "        D_in, H, D_out = 768, 50, 2\n",
+    "\n",
+    "        # Instantiate BERT model\n",
+    "        self.bert = BertModel.from_pretrained('bert-base-uncased')\n",
+    "\n",
+    "        # Instantiate an one-layer feed-forward classifier\n",
+    "        self.classifier = nn.Sequential(\n",
+    "            nn.Linear(D_in, H),\n",
+    "            nn.ReLU(),\n",
+    "            #nn.Dropout(0.5),\n",
+    "            nn.Linear(H, D_out)\n",
+    "        )\n",
+    "\n",
+    "        # Freeze the BERT model\n",
+    "        if freeze_bert:\n",
+    "            for param in self.bert.parameters():\n",
+    "                param.requires_grad = False\n",
+    "        \n",
+    "    def forward(self, input_ids, attention_mask):\n",
+    "        \"\"\"\n",
+    "        Feed input to BERT and the classifier to compute logits.\n",
+    "        @param    input_ids (torch.Tensor): an input tensor with shape (batch_size,\n",
+    "                      max_length)\n",
+    "        @param    attention_mask (torch.Tensor): a tensor that hold attention mask\n",
+    "                      information with shape (batch_size, max_length)\n",
+    "        @return   logits (torch.Tensor): an output tensor with shape (batch_size,\n",
+    "                      num_labels)\n",
+    "        \"\"\"\n",
+    "        # Feed input to BERT\n",
+    "        outputs = self.bert(input_ids=input_ids,\n",
+    "                            attention_mask=attention_mask)\n",
+    "        \n",
+    "        # Extract the last hidden state of the token `[CLS]` for classification task\n",
+    "        last_hidden_state_cls = outputs[0][:, 0, :]\n",
+    "\n",
+    "        # Feed input to classifier to compute logits\n",
+    "        logits = self.classifier(last_hidden_state_cls)\n",
+    "\n",
+    "        return logits"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 22,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:02:30.655449Z",
+     "start_time": "2022-06-25T09:02:30.644656Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "from transformers import AdamW, get_linear_schedule_with_warmup\n",
+    "\n",
+    "def initialize_model(epochs=4):\n",
+    "    \"\"\"Initialize the Bert Classifier, the optimizer and the learning rate scheduler.\n",
+    "    \"\"\"\n",
+    "    # Instantiate Bert Classifier\n",
+    "    bert_classifier = BertClassifier(freeze_bert=False)\n",
+    "\n",
+    "    # Tell PyTorch to run the model on GPU\n",
+    "    bert_classifier.to(device)\n",
+    "\n",
+    "    # Create the optimizer\n",
+    "    optimizer = AdamW(bert_classifier.parameters(),\n",
+    "                      lr=5e-5,    # Default learning rate\n",
+    "                      eps=1e-8    # Default epsilon value\n",
+    "                      )\n",
+    "\n",
+    "    # Total number of training steps\n",
+    "    total_steps = len(train_dataloader) * epochs\n",
+    "\n",
+    "    # Set up the learning rate scheduler\n",
+    "    scheduler = get_linear_schedule_with_warmup(optimizer,\n",
+    "                                                num_warmup_steps=0, # Default value\n",
+    "                                                num_training_steps=total_steps)\n",
+    "    return bert_classifier, optimizer, scheduler"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 25,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:12:53.857467Z",
+     "start_time": "2022-06-25T09:12:53.844730Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "import random\n",
+    "import time\n",
+    "\n",
+    "# Specify loss function\n",
+    "loss_fn = nn.CrossEntropyLoss()\n",
+    "\n",
+    "def set_seed(seed_value=42):\n",
+    "    \"\"\"Set seed for reproducibility.\n",
+    "    \"\"\"\n",
+    "    random.seed(seed_value)\n",
+    "    np.random.seed(seed_value)\n",
+    "    torch.manual_seed(seed_value)\n",
+    "    torch.cuda.manual_seed_all(seed_value)\n",
+    "\n",
+    "def train(model, train_dataloader, val_dataloader=None, epochs=4, evaluation=False):\n",
+    "    \"\"\"Train the BertClassifier model.\n",
+    "    \"\"\"\n",
+    "    # Start training loop\n",
+    "    print(\"Start training...\\n\")\n",
+    "    for epoch_i in range(epochs):\n",
+    "        # =======================================\n",
+    "        #               Training\n",
+    "        # =======================================\n",
+    "        # Print the header of the result table\n",
+    "        print(f\"{'Epoch':^7} | {'Batch':^7} | {'Train Loss':^12} | {'Val Loss':^10} | {'Val Acc':^9} | {'Elapsed':^9}\")\n",
+    "        print(\"-\"*70)\n",
+    "\n",
+    "        # Measure the elapsed time of each epoch\n",
+    "        t0_epoch, t0_batch = time.time(), time.time()\n",
+    "\n",
+    "        # Reset tracking variables at the beginning of each epoch\n",
+    "        total_loss, batch_loss, batch_counts = 0, 0, 0\n",
+    "\n",
+    "        # Put the model into the training mode\n",
+    "        model.train()\n",
+    "\n",
+    "        # For each batch of training data...\n",
+    "        for step, batch in enumerate(train_dataloader):\n",
+    "            batch_counts +=1\n",
+    "            # Load batch to GPU\n",
+    "            b_input_ids, b_attn_mask, b_labels = tuple(t.to(device) for t in batch)\n",
+    "\n",
+    "            # Zero out any previously calculated gradients\n",
+    "            model.zero_grad()\n",
+    "\n",
+    "            # Perform a forward pass. This will return logits.\n",
+    "            logits = model(b_input_ids, b_attn_mask)\n",
+    "\n",
+    "            # Compute loss and accumulate the loss values\n",
+    "            loss = loss_fn(logits, b_labels)\n",
+    "            batch_loss += loss.item()\n",
+    "            total_loss += loss.item()\n",
+    "\n",
+    "            # Perform a backward pass to calculate gradients\n",
+    "            loss.backward()\n",
+    "\n",
+    "            # Clip the norm of the gradients to 1.0 to prevent \"exploding gradients\"\n",
+    "            torch.nn.utils.clip_grad_norm_(model.parameters(), 1.0)\n",
+    "\n",
+    "            # Update parameters and the learning rate\n",
+    "            optimizer.step()\n",
+    "            scheduler.step()\n",
+    "\n",
+    "            # Print the loss values and time elapsed for every 20 batches\n",
+    "            if (step % 5 == 0 and step != 0) or (step == len(train_dataloader) - 1):\n",
+    "                # Calculate time elapsed for 20 batches\n",
+    "                time_elapsed = time.time() - t0_batch\n",
+    "\n",
+    "                # Print training results\n",
+    "                print(f\"{epoch_i + 1:^7} | {step:^7} | {batch_loss / batch_counts:^12.6f} | {'-':^10} | {'-':^9} | {time_elapsed:^9.2f}\")\n",
+    "\n",
+    "                # Reset batch tracking variables\n",
+    "                batch_loss, batch_counts = 0, 0\n",
+    "                t0_batch = time.time()\n",
+    "\n",
+    "        # Calculate the average loss over the entire training data\n",
+    "        avg_train_loss = total_loss / len(train_dataloader)\n",
+    "\n",
+    "        print(\"-\"*70)\n",
+    "        # =======================================\n",
+    "        #               Evaluation\n",
+    "        # =======================================\n",
+    "        if evaluation == True:\n",
+    "            # After the completion of each training epoch, measure the model's performance\n",
+    "            # on our validation set.\n",
+    "            val_loss, val_accuracy = evaluate(model, val_dataloader)\n",
+    "\n",
+    "            # Print performance over the entire training data\n",
+    "            time_elapsed = time.time() - t0_epoch\n",
+    "            \n",
+    "            print(f\"{epoch_i + 1:^7} | {'-':^7} | {avg_train_loss:^12.6f} | {val_loss:^10.6f} | {val_accuracy:^9.2f} | {time_elapsed:^9.2f}\")\n",
+    "            print(\"-\"*70)\n",
+    "        print(\"\\n\")\n",
+    "    \n",
+    "    print(\"Training complete!\")\n",
+    "\n",
+    "\n",
+    "def evaluate(model, val_dataloader):\n",
+    "    \"\"\"After the completion of each training epoch, measure the model's performance\n",
+    "    on our validation set.\n",
+    "    \"\"\"\n",
+    "    # Put the model into the evaluation mode. The dropout layers are disabled during\n",
+    "    # the test time.\n",
+    "    model.eval()\n",
+    "\n",
+    "    # Tracking variables\n",
+    "    val_accuracy = []\n",
+    "    val_loss = []\n",
+    "\n",
+    "    # For each batch in our validation set...\n",
+    "    for batch in val_dataloader:\n",
+    "        # Load batch to GPU\n",
+    "        b_input_ids, b_attn_mask, b_labels = tuple(t.to(device) for t in batch)\n",
+    "\n",
+    "        # Compute logits\n",
+    "        with torch.no_grad():\n",
+    "            logits = model(b_input_ids, b_attn_mask)\n",
+    "\n",
+    "        # Compute loss\n",
+    "        loss = loss_fn(logits, b_labels)\n",
+    "        val_loss.append(loss.item())\n",
+    "\n",
+    "        # Get the predictions\n",
+    "        preds = torch.argmax(logits, dim=1).flatten()\n",
+    "\n",
+    "        # Calculate the accuracy rate\n",
+    "        accuracy = (preds == b_labels).cpu().numpy().mean() * 100\n",
+    "        val_accuracy.append(accuracy)\n",
+    "\n",
+    "    # Compute the average accuracy and loss over the validation set.\n",
+    "    val_loss = np.mean(val_loss)\n",
+    "    val_accuracy = np.mean(val_accuracy)\n",
+    "\n",
+    "    return val_loss, val_accuracy"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 26,
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-06-25T09:54:42.915823Z",
+     "start_time": "2022-06-25T09:12:58.201795Z"
+    }
+   },
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "Some weights of the model checkpoint at bert-base-uncased were not used when initializing BertModel: ['cls.predictions.transform.dense.weight', 'cls.predictions.transform.LayerNorm.weight', 'cls.seq_relationship.weight', 'cls.seq_relationship.bias', 'cls.predictions.transform.dense.bias', 'cls.predictions.transform.LayerNorm.bias', 'cls.predictions.decoder.weight', 'cls.predictions.bias']\n",
+      "- This IS expected if you are initializing BertModel from the checkpoint of a model trained on another task or with another architecture (e.g. initializing a BertForSequenceClassification model from a BertForPreTraining model).\n",
+      "- This IS NOT expected if you are initializing BertModel from the checkpoint of a model that you expect to be exactly identical (initializing a BertForSequenceClassification model from a BertForSequenceClassification model).\n"
+     ]
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Start training...\n",
+      "\n",
+      " Epoch  |  Batch  |  Train Loss  |  Val Loss  |  Val Acc  |  Elapsed \n",
+      "----------------------------------------------------------------------\n",
+      "   1    |    5    |   0.685621   |     -      |     -     |   79.83  \n",
+      "   1    |   10    |   0.669755   |     -      |     -     |   60.98  \n",
+      "   1    |   15    |   0.636234   |     -      |     -     |   60.81  \n",
+      "   1    |   20    |   0.603634   |     -      |     -     |   60.93  \n",
+      "   1    |   25    |   0.573587   |     -      |     -     |   60.90  \n",
+      "   1    |   30    |   0.594417   |     -      |     -     |   61.13  \n",
+      "   1    |   35    |   0.577772   |     -      |     -     |   60.90  \n",
+      "   1    |   40    |   0.564313   |     -      |     -     |   61.48  \n",
+      "   1    |   45    |   0.467151   |     -      |     -     |   61.49  \n",
+      "   1    |   50    |   0.477319   |     -      |     -     |   61.96  \n",
+      "   1    |   55    |   0.487433   |     -      |     -     |   61.16  \n",
+      "   1    |   60    |   0.407353   |     -      |     -     |   60.69  \n",
+      "   1    |   65    |   0.532023   |     -      |     -     |   60.32  \n",
+      "   1    |   70    |   0.529829   |     -      |     -     |   60.40  \n",
+      "   1    |   75    |   0.443143   |     -      |     -     |   60.19  \n",
+      "   1    |   80    |   0.432639   |     -      |     -     |   60.50  \n",
+      "   1    |   85    |   0.506726   |     -      |     -     |   60.32  \n",
+      "   1    |   90    |   0.442358   |     -      |     -     |   60.45  \n",
+      "   1    |   95    |   0.539845   |     -      |     -     |   55.92  \n",
+      "----------------------------------------------------------------------\n",
+      "   1    |    -    |   0.536889   |  0.426069  |   80.68   |  1208.44 \n",
+      "----------------------------------------------------------------------\n",
+      "\n",
+      "\n",
+      " Epoch  |  Batch  |  Train Loss  |  Val Loss  |  Val Acc  |  Elapsed \n",
+      "----------------------------------------------------------------------\n",
+      "   2    |    5    |   0.325858   |     -      |     -     |   82.61  \n",
+      "   2    |   10    |   0.307421   |     -      |     -     |   66.54  \n",
+      "   2    |   15    |   0.317675   |     -      |     -     |   64.03  \n",
+      "   2    |   20    |   0.326934   |     -      |     -     |   63.01  \n",
+      "   2    |   25    |   0.325949   |     -      |     -     |   63.21  \n",
+      "   2    |   30    |   0.341778   |     -      |     -     |   63.01  \n",
+      "   2    |   35    |   0.273992   |     -      |     -     |   63.04  \n",
+      "   2    |   40    |   0.247418   |     -      |     -     |   64.86  \n",
+      "   2    |   45    |   0.264468   |     -      |     -     |   64.09  \n",
+      "   2    |   50    |   0.370117   |     -      |     -     |   63.30  \n",
+      "   2    |   55    |   0.256397   |     -      |     -     |   66.72  \n",
+      "   2    |   60    |   0.298844   |     -      |     -     |   65.71  \n",
+      "   2    |   65    |   0.371179   |     -      |     -     |   70.41  \n",
+      "   2    |   70    |   0.191519   |     -      |     -     |   66.28  \n",
+      "   2    |   75    |   0.354108   |     -      |     -     |   66.15  \n",
+      "   2    |   80    |   0.326162   |     -      |     -     |   66.60  \n",
+      "   2    |   85    |   0.273768   |     -      |     -     |   67.04  \n",
+      "   2    |   90    |   0.270890   |     -      |     -     |   65.44  \n",
+      "   2    |   95    |   0.294375   |     -      |     -     |   60.52  \n",
+      "----------------------------------------------------------------------\n",
+      "   2    |    -    |   0.302293   |  0.425262  |   81.70   |  1293.09 \n",
+      "----------------------------------------------------------------------\n",
+      "\n",
+      "\n",
+      "Training complete!\n"
+     ]
+    }
+   ],
+   "source": [
+    "set_seed(42)    # Set seed for reproducibility\n",
+    "bert_classifier, optimizer, scheduler = initialize_model(epochs=2)\n",
+    "train(bert_classifier, train_dataloader, val_dataloader, epochs=2, evaluation=True)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.6.8"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}