[PYTHON] 100 language processing knocks 2020 [00 ~ 89 answer]

This is a continuation of 100 Language Processing Knock 2020 Chapter 8: Neural Net.

This article deals with RNNs and CNNs in Chapter 9 (80-89).

Link

I've included only the code in this article. Please refer to the link below for supplements on problem sentences and how to solve them.

Language Processing 100 Knock 2020 Chapter 9: RNN, CNN

Chapter 9: RNN, CNN

80. Conversion to ID number

import numpy as np
import pandas as pd
from sklearn.feature_extraction.text import CountVectorizer
train = pd.read_csv(base+'train.txt', header=None, sep='\t') 
valid = pd.read_csv(base+'valid.txt', header=None, sep='\t') 
test = pd.read_csv(base+'test.txt', header=None, sep='\t') 
vectorizer = CountVectorizer(min_df=2)
train_title = train.iloc[:,1].str.lower()
cnt = vectorizer.fit_transform(train_title).toarray()
sm = cnt.sum(axis=0)
idx = np.argsort(sm)[::-1]
words = np.array(vectorizer.get_feature_names())[idx]
d = dict()
for i in range(len(words)):
  d[words[i]] = i+1
def get_id(sentence):
  r = []
  for word in sentence:
    r.append(d.get(word,0))
  return r

def df2id(df):
  ids = []
  for i in df.iloc[:,1].str.lower():
    ids.append(get_id(i.split()))
  return ids

X_train = df2id(train)
X_valid = df2id(valid)
X_test = df2id(test)

81. Forecast by RNN

import torch
dw = 300
dh = 50
class RNN(torch.nn.Module):
    def __init__(self):
        super().__init__()
        self.emb = torch.nn.Embedding(len(words)+1,dw)
        self.rnn = torch.nn.RNN(dw,dh,batch_first=True)
        self.linear = torch.nn.Linear(dh,4)
        self.softmax = torch.nn.Softmax()
    def forward(self, x, h=None):
        x = self.emb(x)
        y, h = self.rnn(x, h)
        y = y[:,-1,:] #Last step
        y = self.linear(y)
        y = self.softmax(y)
        return y

82. Learning by stochastic gradient descent

import torch
from torch.utils.data import TensorDataset, DataLoader
from torch.utils.tensorboard import SummaryWriter
%load_ext tensorboard
!rm -rf ./runs
%tensorboard --logdir ./runs
writer = SummaryWriter()

max_len = 10
dw = 300
dh = 50
n_vocab = len(words) + 2
PAD = len(words) + 1

class RNN(torch.nn.Module):
    def __init__(self):
        super().__init__()
        self.emb = torch.nn.Embedding(n_vocab,dw,padding_idx=PAD)
        self.rnn = torch.nn.RNN(dw,dh,batch_first=True)
        self.linear = torch.nn.Linear(dh,4)
        self.softmax = torch.nn.Softmax()
    def forward(self, x, h=None):
        x = self.emb(x)
        y, h = self.rnn(x, h)
        y = y[:,-1,:] #Last step
        y = self.linear(y)
        # y = self.softmax(y) # torch.nn.CrossEntropyLoss()Includes softmax
        return y

def list2tensor(data, max_len):
  new = []
  for d in data:
    if len(d) > max_len:
      d = d[:max_len]
    else:
      d += [PAD] * (max_len - len(d))
    new.append(d)
  return torch.tensor(new, dtype=torch.int64)

def accuracy(pred, label):
  pred = np.argmax(pred.data.numpy(), axis=1)
  label = label.data.numpy()
  return (pred == label).mean()



train = pd.read_csv(base+'train.txt', header=None, sep='\t') 
valid = pd.read_csv(base+'valid.txt', header=None, sep='\t') 
test = pd.read_csv(base+'test.txt', header=None, sep='\t') 

X_train = df2id(train)
X_valid = df2id(valid)
X_test = df2id(test)

X_train = list2tensor(X_train,max_len)
X_valid = list2tensor(X_valid,max_len)
X_test = list2tensor(X_test,max_len)

y_train = np.loadtxt(base+'y_train.txt')
y_train = torch.tensor(y_train, dtype=torch.int64)
y_valid = np.loadtxt(base+'y_valid.txt')
y_valid = torch.tensor(y_valid, dtype=torch.int64)
y_test = np.loadtxt(base+'y_test.txt')
y_test = torch.tensor(y_test, dtype=torch.int64)


model = RNN()
ds = TensorDataset(X_train, y_train)
#Create DataLoader
loader = DataLoader(ds, batch_size=1, shuffle=True)
loss_fn = torch.nn.CrossEntropyLoss()
optimizer = torch.optim.SGD(model.parameters(), lr=1e-1)

for epoch in range(2):
    for xx, yy in loader:
        y_pred = model(xx)
        loss = loss_fn(y_pred, yy)
        optimizer.zero_grad()
        loss.backward()
        optimizer.step()
    with torch.no_grad():
      y_pred = model(X_train)
      loss = loss_fn(y_pred, y_train) 
      writer.add_scalar('Loss/train', loss, epoch)
      writer.add_scalar('Accuracy/train', accuracy(y_pred,y_train), epoch)
      print (accuracy(y_pred,y_train))

      y_pred = model(X_valid)
      loss = loss_fn(y_pred, y_valid)
      writer.add_scalar('Loss/valid', loss, epoch)
      writer.add_scalar('Accuracy/valid', accuracy(y_pred,y_valid), epoch)
      print (accuracy(y_pred,y_valid))

83. Mini-batch / Learning on GPU

import torch
from torch.utils.data import TensorDataset, DataLoader
from torch.utils.tensorboard import SummaryWriter
%load_ext tensorboard
!rm -rf ./runs
%tensorboard --logdir ./runs
writer = SummaryWriter()

max_len = 10
dw = 300
dh = 50
n_vocab = len(words) + 2
PAD = len(words) + 1

class RNN(torch.nn.Module):
    def __init__(self):
        super().__init__()
        self.emb = torch.nn.Embedding(n_vocab,dw,padding_idx=PAD)
        self.rnn = torch.nn.RNN(dw,dh,batch_first=True)
        self.linear = torch.nn.Linear(dh,4)
        self.softmax = torch.nn.Softmax()
    def forward(self, x, h=None):
        x = self.emb(x)
        y, h = self.rnn(x, h)
        y = y[:,-1,:] #Last step
        y = self.linear(y)
        # y = self.softmax(y) # torch.nn.CrossEntropyLoss()Includes softmax
        return y

def list2tensor(data, max_len):
  new = []
  for d in data:
    if len(d) > max_len:
      d = d[:max_len]
    else:
      d += [PAD] * (max_len - len(d))
    new.append(d)
  return torch.tensor(new, dtype=torch.int64)

def accuracy(pred, label):
  pred = np.argmax(pred.data.to('cpu').numpy(), axis=1)
  label = label.data.to('cpu').numpy()
  return (pred == label).mean()

train = pd.read_csv(base+'train.txt', header=None, sep='\t') 
valid = pd.read_csv(base+'valid.txt', header=None, sep='\t') 
test = pd.read_csv(base+'test.txt', header=None, sep='\t') 

X_train = df2id(train)
X_valid = df2id(valid)
X_test = df2id(test)

X_train = list2tensor(X_train,max_len)
X_valid = list2tensor(X_valid,max_len)
X_test = list2tensor(X_test,max_len)

y_train = np.loadtxt(base+'y_train.txt')
y_train = torch.tensor(y_train, dtype=torch.int64)
y_valid = np.loadtxt(base+'y_valid.txt')
y_valid = torch.tensor(y_valid, dtype=torch.int64)
y_test = np.loadtxt(base+'y_test.txt')
y_test = torch.tensor(y_test, dtype=torch.int64)


model = RNN()
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = model.to(device)
ds = TensorDataset(X_train.to(device), y_train.to(device))
#Create DataLoader
loader = DataLoader(ds, batch_size=1024, shuffle=True)
loss_fn = torch.nn.CrossEntropyLoss()
optimizer = torch.optim.SGD(model.parameters(), lr=1e-1)

for epoch in range(10):
    for xx, yy in loader:
        y_pred = model(xx)
        loss = loss_fn(y_pred, yy)
        optimizer.zero_grad()
        loss.backward()
        optimizer.step()
    with torch.no_grad():
      y_pred = model(X_train.to(device))
      loss = loss_fn(y_pred, y_train.to(device)) 
      writer.add_scalar('Loss/train', loss, epoch)
      writer.add_scalar('Accuracy/train', accuracy(y_pred,y_train), epoch)
      print (accuracy(y_pred,y_train))

      y_pred = model(X_valid.to(device))
      loss = loss_fn(y_pred, y_valid.to(device))
      writer.add_scalar('Loss/valid', loss, epoch)
      writer.add_scalar('Accuracy/valid', accuracy(y_pred,y_valid), epoch)
      print (accuracy(y_pred,y_valid))

84. Introduction of word vector

import torch
from torch.utils.data import TensorDataset, DataLoader
from torch.utils.tensorboard import SummaryWriter

max_len = 10
dw = 300
dh = 50
n_vocab = len(words) + 2
PAD = len(words) + 1

class RNN(torch.nn.Module):
    def __init__(self):
        super().__init__()
        self.emb = torch.nn.Embedding(n_vocab,dw,padding_idx=PAD)
        self.rnn = torch.nn.RNN(dw,dh,batch_first=True)
        self.linear = torch.nn.Linear(dh,4)
        self.softmax = torch.nn.Softmax()
    def forward(self, x, h=None):
        x = self.emb(x)
        y, h = self.rnn(x, h)
        y = y[:,-1,:] #Last step
        y = self.linear(y)
        # y = self.softmax(y) # torch.nn.CrossEntropyLoss()Includes softmax
        return y

def list2tensor(data, max_len):
  new = []
  for d in data:
    if len(d) > max_len:
      d = d[:max_len]
    else:
      d += [PAD] * (max_len - len(d))
    new.append(d)
  return torch.tensor(new, dtype=torch.int64)

def accuracy(pred, label):
  pred = np.argmax(pred.data.to('cpu').numpy(), axis=1)
  label = label.data.to('cpu').numpy()
  return (pred == label).mean()


train = pd.read_csv(base+'train.txt', header=None, sep='\t') 
valid = pd.read_csv(base+'valid.txt', header=None, sep='\t') 
test = pd.read_csv(base+'test.txt', header=None, sep='\t') 

X_train = df2id(train)
X_valid = df2id(valid)
X_test = df2id(test)

X_train = list2tensor(X_train,max_len)
X_valid = list2tensor(X_valid,max_len)
X_test = list2tensor(X_test,max_len)

y_train = np.loadtxt(base+'y_train.txt')
y_train = torch.tensor(y_train, dtype=torch.int64)
y_valid = np.loadtxt(base+'y_valid.txt')
y_valid = torch.tensor(y_valid, dtype=torch.int64)
y_test = np.loadtxt(base+'y_test.txt')
y_test = torch.tensor(y_test, dtype=torch.int64)

model = RNN()
#print (model.emb.weight)
for k,v in d.items():
  if k in w2v.vocab:
    #v = np.random.randint(1,PAD) #Does a random word vector work?
    model.emb.weight[v] = torch.tensor(w2v[k], dtype=torch.float32)
#print (model.emb.weight)
model.emb.weight = torch.nn.Parameter(model.emb.weight)

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = model.to(device)

ds = TensorDataset(X_train.to(device), y_train.to(device))
#Create DataLoader
loader = DataLoader(ds, batch_size=1024, shuffle=True)
loss_fn = torch.nn.CrossEntropyLoss()
optimizer = torch.optim.SGD(model.parameters(), lr=1e-1)

for epoch in range(10):
    for xx, yy in loader:
        y_pred = model(xx)
        loss = loss_fn(y_pred, yy)
        optimizer.zero_grad()
        loss.backward()
        optimizer.step()
    with torch.no_grad():
      y_pred = model(X_train.to(device))
      loss = loss_fn(y_pred, y_train.to(device)) 
      writer.add_scalar('Loss/train', loss, epoch)
      writer.add_scalar('Accuracy/train', accuracy(y_pred,y_train), epoch)
      print (accuracy(y_pred,y_train))

      y_pred = model(X_valid.to(device))
      loss = loss_fn(y_pred, y_valid.to(device))
      writer.add_scalar('Loss/valid', loss, epoch)
      writer.add_scalar('Accuracy/valid', accuracy(y_pred,y_valid), epoch)
      print (accuracy(y_pred,y_valid))
#print (model.emb.weight)

85. Bi-directional RNN / multi-layer

import torch
from torch.utils.data import TensorDataset, DataLoader
from torch.utils.tensorboard import SummaryWriter

max_len = 10
dw = 300
dh = 50
n_vocab = len(words) + 2
PAD = len(words) + 1

class RNN(torch.nn.Module):
    def __init__(self):
        super().__init__()
        self.emb = torch.nn.Embedding(n_vocab,dw,padding_idx=PAD)
        self.rnn1 = torch.nn.RNN(dw,dh,bidirectional=True,batch_first=True)
        self.rnn2 = torch.nn.RNN(2*dh,dh,bidirectional=True,batch_first=True)
        self.rnn3 = torch.nn.RNN(2*dh,dh,bidirectional=True,batch_first=True)
        self.linear = torch.nn.Linear(2*dh,4)
        self.softmax = torch.nn.Softmax()
    def forward(self, x, h=None):
        x = self.emb(x)
        y, h = self.rnn1(x, h)
        y, h = self.rnn2(y, h)
        y, h = self.rnn3(y, h)
        y = y[:,-1,:] #Last step
        y = self.linear(y)
        # y = self.softmax(y) # torch.nn.CrossEntropyLoss()Includes softmax
        return y

def list2tensor(data, max_len):
  new = []
  for d in data:
    if len(d) > max_len:
      d = d[:max_len]
    else:
      d += [PAD] * (max_len - len(d))
    new.append(d)
  return torch.tensor(new, dtype=torch.int64)

def accuracy(pred, label):
  pred = np.argmax(pred.data.to('cpu').numpy(), axis=1)
  label = label.data.to('cpu').numpy()
  return (pred == label).mean()


train = pd.read_csv(base+'train.txt', header=None, sep='\t') 
valid = pd.read_csv(base+'valid.txt', header=None, sep='\t') 
test = pd.read_csv(base+'test.txt', header=None, sep='\t') 

X_train = df2id(train)
X_valid = df2id(valid)
X_test = df2id(test)

X_train = list2tensor(X_train,max_len)
X_valid = list2tensor(X_valid,max_len)
X_test = list2tensor(X_test,max_len)

y_train = np.loadtxt(base+'y_train.txt')
y_train = torch.tensor(y_train, dtype=torch.int64)
y_valid = np.loadtxt(base+'y_valid.txt')
y_valid = torch.tensor(y_valid, dtype=torch.int64)
y_test = np.loadtxt(base+'y_test.txt')
y_test = torch.tensor(y_test, dtype=torch.int64)

model = RNN()
#print (model.emb.weight)
for k,v in d.items():
  if k in w2v.vocab:
    #v = np.random.randint(1,PAD) #Does a random word vector work?
    model.emb.weight[v] = torch.tensor(w2v[k], dtype=torch.float32)
#print (model.emb.weight)
model.emb.weight = torch.nn.Parameter(model.emb.weight)

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = model.to(device)

ds = TensorDataset(X_train.to(device), y_train.to(device))
#Create DataLoader
loader = DataLoader(ds, batch_size=1024, shuffle=True)
loss_fn = torch.nn.CrossEntropyLoss()
optimizer = torch.optim.SGD(model.parameters(), lr=1e-1)

for epoch in range(10):
    for xx, yy in loader:
        y_pred = model(xx)
        loss = loss_fn(y_pred, yy)
        optimizer.zero_grad()
        loss.backward()
        optimizer.step()
    with torch.no_grad():
      y_pred = model(X_train.to(device))
      loss = loss_fn(y_pred, y_train.to(device)) 
      writer.add_scalar('Loss/train', loss, epoch)
      writer.add_scalar('Accuracy/train', accuracy(y_pred,y_train), epoch)
      print (accuracy(y_pred,y_train))

      y_pred = model(X_valid.to(device))
      loss = loss_fn(y_pred, y_valid.to(device))
      writer.add_scalar('Loss/valid', loss, epoch)
      writer.add_scalar('Accuracy/valid', accuracy(y_pred,y_valid), epoch)
      print (accuracy(y_pred,y_valid))

86. Convolutional Neural Network (CNN)

import torch
from torch.utils.data import TensorDataset, DataLoader
from torch.utils.tensorboard import SummaryWriter

max_len = 10
dw = 300
dh = 50
n_vocab = len(words) + 2
PAD = len(words) + 1

class CNN(torch.nn.Module):
    def __init__(self):
        super().__init__()
        self.emb = torch.nn.Embedding(n_vocab,dw,padding_idx=PAD)
        self.conv = torch.nn.Conv1d(dw,dh,3,padding=1) # in_channels:dw, out_channels: dh
        self.relu = torch.nn.ReLU()
        self.pool = torch.nn.MaxPool1d(max_len)
        self.linear = torch.nn.Linear(dh,4)
        self.softmax = torch.nn.Softmax()
    def forward(self, x, h=None):
        x = self.emb(x)
        x = x.view(x.shape[0], x.shape[2], x.shape[1])
        x = self.conv(x)
        x = self.relu(x)
        x = x.view(x.shape[0], x.shape[1], x.shape[2])
        x = self.pool(x)
        x = x.view(x.shape[0], x.shape[1])
        y = self.linear(x)
        y = self.softmax(y) # torch.nn.CrossEntropyLoss()Includes softmax
        return y

def list2tensor(data, max_len):
  new = []
  for d in data:
    if len(d) > max_len:
      d = d[:max_len]
    else:
      d += [PAD] * (max_len - len(d))
    new.append(d)
  return torch.tensor(new, dtype=torch.int64)

def accuracy(pred, label):
  pred = np.argmax(pred.data.to('cpu').numpy(), axis=1)
  label = label.data.to('cpu').numpy()
  return (pred == label).mean()


train = pd.read_csv(base+'train.txt', header=None, sep='\t') 
valid = pd.read_csv(base+'valid.txt', header=None, sep='\t') 
test = pd.read_csv(base+'test.txt', header=None, sep='\t') 

X_train = df2id(train)
X_valid = df2id(valid)
X_test = df2id(test)

X_train = list2tensor(X_train,max_len)
X_valid = list2tensor(X_valid,max_len)
X_test = list2tensor(X_test,max_len)

y_train = np.loadtxt(base+'y_train.txt')
y_train = torch.tensor(y_train, dtype=torch.int64)
y_valid = np.loadtxt(base+'y_valid.txt')
y_valid = torch.tensor(y_valid, dtype=torch.int64)
y_test = np.loadtxt(base+'y_test.txt')
y_test = torch.tensor(y_test, dtype=torch.int64)

model = CNN()
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = model.to(device)
with torch.no_grad():
  y_pred = model(X_train.to(device))

87. Learning CNN by Stochastic Gradient Descent

import torch
from torch.utils.data import TensorDataset, DataLoader
from torch.utils.tensorboard import SummaryWriter

max_len = 10
dw = 300
dh = 50
n_vocab = len(words) + 2
PAD = len(words) + 1

class CNN(torch.nn.Module):
    def __init__(self):
        super().__init__()
        self.emb = torch.nn.Embedding(n_vocab,dw,padding_idx=PAD)
        self.conv = torch.nn.Conv1d(dw,dh,3,padding=1) # in_channels:dw, out_channels: dh
        self.relu = torch.nn.ReLU()
        self.pool = torch.nn.MaxPool1d(max_len)
        self.linear = torch.nn.Linear(dh,4)
        self.softmax = torch.nn.Softmax()
    def forward(self, x, h=None):
        x = self.emb(x)
        x = x.view(x.shape[0], x.shape[2], x.shape[1])
        x = self.conv(x)
        x = self.relu(x)
        x = x.view(x.shape[0], x.shape[1], x.shape[2])
        x = self.pool(x)
        x = x.view(x.shape[0], x.shape[1])
        y = self.linear(x)
        return y

def list2tensor(data, max_len):
  new = []
  for d in data:
    if len(d) > max_len:
      d = d[:max_len]
    else:
      d += [PAD] * (max_len - len(d))
    new.append(d)
  return torch.tensor(new, dtype=torch.int64)

def accuracy(pred, label):
  pred = np.argmax(pred.data.to('cpu').numpy(), axis=1)
  label = label.data.to('cpu').numpy()
  return (pred == label).mean()


train = pd.read_csv(base+'train.txt', header=None, sep='\t') 
valid = pd.read_csv(base+'valid.txt', header=None, sep='\t') 
test = pd.read_csv(base+'test.txt', header=None, sep='\t') 

X_train = df2id(train)
X_valid = df2id(valid)
X_test = df2id(test)

X_train = list2tensor(X_train,max_len)
X_valid = list2tensor(X_valid,max_len)
X_test = list2tensor(X_test,max_len)

y_train = np.loadtxt(base+'y_train.txt')
y_train = torch.tensor(y_train, dtype=torch.int64)
y_valid = np.loadtxt(base+'y_valid.txt')
y_valid = torch.tensor(y_valid, dtype=torch.int64)
y_test = np.loadtxt(base+'y_test.txt')
y_test = torch.tensor(y_test, dtype=torch.int64)

model = CNN()
#print (model.emb.weight)
for k,v in d.items():
  if k in w2v.vocab:
    #v = np.random.randint(1,PAD) #Does a random word vector work?
    model.emb.weight[v] = torch.tensor(w2v[k], dtype=torch.float32)
#print (model.emb.weight)

model.emb.weight = torch.nn.Parameter(model.emb.weight)

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = model.to(device)

ds = TensorDataset(X_train.to(device), y_train.to(device))
#Create DataLoader
loader = DataLoader(ds, batch_size=1024, shuffle=True)
loss_fn = torch.nn.CrossEntropyLoss()
optimizer = torch.optim.SGD(model.parameters(), lr=1e-1)
for epoch in range(10):
    for xx, yy in loader:
        y_pred = model(xx)
        loss = loss_fn(y_pred, yy)
        optimizer.zero_grad()
        loss.backward()
        optimizer.step()
    with torch.no_grad():
      y_pred = model(X_train.to(device))
      loss = loss_fn(y_pred, y_train.to(device)) 
      writer.add_scalar('Loss/train', loss, epoch)
      writer.add_scalar('Accuracy/train', accuracy(y_pred,y_train), epoch)
      print (accuracy(y_pred,y_train))

      y_pred = model(X_valid.to(device))
      loss = loss_fn(y_pred, y_valid.to(device))
      writer.add_scalar('Loss/valid', loss, epoch)
      writer.add_scalar('Accuracy/valid', accuracy(y_pred,y_valid), epoch)
      print (accuracy(y_pred,y_valid))

88. Parameter tuning

import torch
from torch.utils.data import TensorDataset, DataLoader
from torch.utils.tensorboard import SummaryWriter

max_len = 10
dw = 300
dh = 50
n_vocab = len(words) + 2
PAD = len(words) + 1

class CNN(torch.nn.Module):
    def __init__(self):
        super().__init__()
        self.emb = torch.nn.Embedding(n_vocab,dw,padding_idx=PAD)
        self.conv = torch.nn.Conv1d(dw,dh,3,padding=1) # in_channels:dw, out_channels: dh
        self.relu = torch.nn.ReLU()
        self.pool = torch.nn.MaxPool1d(max_len)
        self.linear = torch.nn.Linear(dh,4)
        self.softmax = torch.nn.Softmax()
    def forward(self, x, h=None):
        x = self.emb(x)
        x = x.view(x.shape[0], x.shape[2], x.shape[1])
        x = self.conv(x)
        x = self.relu(x)
        x = x.view(x.shape[0], x.shape[1], x.shape[2])
        x = self.pool(x)
        x = x.view(x.shape[0], x.shape[1])
        y = self.linear(x)
        return y

def list2tensor(data, max_len):
  new = []
  for d in data:
    if len(d) > max_len:
      d = d[:max_len]
    else:
      d += [PAD] * (max_len - len(d))
    new.append(d)
  return torch.tensor(new, dtype=torch.int64)

def accuracy(pred, label):
  pred = np.argmax(pred.data.to('cpu').numpy(), axis=1)
  label = label.data.to('cpu').numpy()
  return (pred == label).mean()


train = pd.read_csv(base+'train.txt', header=None, sep='\t') 
valid = pd.read_csv(base+'valid.txt', header=None, sep='\t') 
test = pd.read_csv(base+'test.txt', header=None, sep='\t') 

X_train = df2id(train)
X_valid = df2id(valid)
X_test = df2id(test)

X_train = list2tensor(X_train,max_len)
X_valid = list2tensor(X_valid,max_len)
X_test = list2tensor(X_test,max_len)

y_train = np.loadtxt(base+'y_train.txt')
y_train = torch.tensor(y_train, dtype=torch.int64)
y_valid = np.loadtxt(base+'y_valid.txt')
y_valid = torch.tensor(y_valid, dtype=torch.int64)
y_test = np.loadtxt(base+'y_test.txt')
y_test = torch.tensor(y_test, dtype=torch.int64)

model = CNN()
#print (model.emb.weight)
for k,v in d.items():
  if k in w2v.vocab:
    #v = np.random.randint(1,PAD) #Does a random word vector work?
    model.emb.weight[v] = torch.tensor(w2v[k], dtype=torch.float32)
#print (model.emb.weight)

model.emb.weight = torch.nn.Parameter(model.emb.weight)

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = model.to(device)

ds = TensorDataset(X_train.to(device), y_train.to(device))
#Create DataLoader
loader = DataLoader(ds, batch_size=1024, shuffle=True)
loss_fn = torch.nn.CrossEntropyLoss()
optimizer = torch.optim.Adam(model.parameters())
for epoch in range(50):
    for xx, yy in loader:
        y_pred = model(xx)
        loss = loss_fn(y_pred, yy)
        optimizer.zero_grad()
        loss.backward()
        optimizer.step()
    with torch.no_grad():
      y_pred = model(X_train.to(device))
      loss = loss_fn(y_pred, y_train.to(device)) 
      writer.add_scalar('Loss/train', loss, epoch)
      writer.add_scalar('Accuracy/train', accuracy(y_pred,y_train), epoch)
      print (accuracy(y_pred,y_train))

      y_pred = model(X_valid.to(device))
      loss = loss_fn(y_pred, y_valid.to(device))
      writer.add_scalar('Loss/valid', loss, epoch)
      writer.add_scalar('Accuracy/valid', accuracy(y_pred,y_valid), epoch)
      print (accuracy(y_pred,y_valid))

89. Transfer learning from a pre-trained language model

!pip install transformers
import torch
from torch.utils.data import TensorDataset, DataLoader
from torch.utils.tensorboard import SummaryWriter
from transformers import *
import torch.nn as nn
import torch.nn.functional as F

max_len = 15
PAD = 0
n_unit =  768

tokenizer_class = BertTokenizer
tokenizer = tokenizer_class.from_pretrained('bert-base-uncased')

def dfs_freeze(model):
    for name, child in model.named_children():
        for param in child.parameters():
            param.requires_grad = False
        dfs_freeze(child)


class BertClassifier(nn.Module):
    def __init__(self, n_classes=4):
        super(BertClassifier, self).__init__()
        self.bert_model = BertModel.from_pretrained('bert-base-uncased') 
        self.fc = nn.Linear(n_unit, n_classes)

    def forward(self, ids):
        seg_ids = torch.zeros_like(ids) #All considered to be the same segment
        attention_mask = (ids > 0)
        last_hidden_state, _ = self.bert_model(input_ids=ids, token_type_ids=seg_ids, attention_mask=attention_mask)
        x = last_hidden_state[:,0,:] #CLS token
        logit = self.fc(x.view(-1,n_unit))
        return logit


def list2tensor(data, max_len):
  new = []
  for d in data:
    if len(d) > max_len:
      d = d[:max_len]
    else:
      d += [PAD] * (max_len - len(d))
    new.append(d)
  return torch.tensor(new, dtype=torch.int64)

def accuracy(pred, label):
  pred = np.argmax(pred.data.to('cpu').numpy(), axis=1)
  label = label.data.to('cpu').numpy()
  return (pred == label).mean()

def df2id(df):
  tokenized = df[1].apply((lambda x: tokenizer.encode(x, add_special_tokens=True)))
  return tokenized

train = pd.read_csv(base+'train.txt', header=None, sep='\t') 
valid = pd.read_csv(base+'valid.txt', header=None, sep='\t') 
test = pd.read_csv(base+'test.txt', header=None, sep='\t') 

X_train = df2id(train)
X_valid = df2id(valid)
X_test = df2id(test)

X_train = list2tensor(X_train,max_len)
X_valid = list2tensor(X_valid,max_len)
X_test = list2tensor(X_test,max_len)

y_train = np.loadtxt(base+'y_train.txt')
y_train = torch.tensor(y_train, dtype=torch.int64)
y_valid = np.loadtxt(base+'y_valid.txt')
y_valid = torch.tensor(y_valid, dtype=torch.int64)
y_test = np.loadtxt(base+'y_test.txt')
y_test = torch.tensor(y_test, dtype=torch.int64)
model = BertClassifier()

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = model.to(device)

dfs_freeze(model)
model.fc.requires_grad_(True)

ds = TensorDataset(X_train.to(device), y_train.to(device))
#Create DataLoader
loader = DataLoader(ds, batch_size=1024, shuffle=True)
loss_fn = torch.nn.CrossEntropyLoss()
optimizer = torch.optim.Adam(model.parameters())
for epoch in range(30):
    print(epoch)
    for xx, yy in loader:
        y_pred = model(xx)
        loss = loss_fn(y_pred, yy)
        optimizer.zero_grad()
        loss.backward()
        optimizer.step()
    with torch.no_grad():
      y_pred = model(X_train.to(device))
      loss = loss_fn(y_pred, y_train.to(device)) 
      writer.add_scalar('Loss/train', loss, epoch)
      writer.add_scalar('Accuracy/train', accuracy(y_pred,y_train), epoch)
      print (accuracy(y_pred,y_train))

      y_pred = model(X_valid.to(device))
      loss = loss_fn(y_pred, y_valid.to(device))
      writer.add_scalar('Loss/valid', loss, epoch)
      writer.add_scalar('Accuracy/valid', accuracy(y_pred,y_valid), epoch)
      print (accuracy(y_pred,y_valid))