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import gradio as gr |
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import torch |
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import torch.nn as nn |
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import torch.functional as F |
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n_embd = 64 |
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dropout = 0.0 |
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block_size = 32 |
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vocab_size = 65 |
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n_head = 4 |
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n_layer = 4 |
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class Head(nn.Module): |
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def __init__(self, head_size): |
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super().__init__() |
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self.key = nn.Linear(n_embd, head_size, bias=False) |
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self.query = nn.Linear(n_embd, head_size, bias=False) |
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self.value = nn.Linear(n_embd, head_size, bias=False) |
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self.register_buffer('tril', torch.tril(torch.ones(block_size, block_size))) |
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self.dropout = nn.Dropout(dropout) |
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def forward(self, x): |
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B,T,C = x.shape |
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k = self.key(x) |
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q = self.query(x) |
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wei = q @ k.transpose(-2,-1) * C**-0.5 |
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wei = wei.masked_fill(self.tril[:T, :T] == 0, float('-inf')) |
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wei = F.softmax(wei, dim=-1) |
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wei = self.dropout(wei) |
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v = self.value(x) |
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out = wei @ v |
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return out |
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class MultiHeadAttention(nn.Module): |
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def __init__(self, num_heads, head_size): |
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super().__init__() |
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self.heads = nn.ModuleList([Head(head_size) for _ in range(num_heads)]) |
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self.proj = nn.Linear(n_embd, n_embd) |
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self.dropout = nn.Dropout(dropout) |
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def forward(self, x): |
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out = torch.cat([h(x) for h in self.heads], dim=-1) |
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out = self.dropout(self.proj(out)) |
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return out |
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class FeedFoward(nn.Module): |
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def __init__(self, n_embd): |
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super().__init__() |
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self.net = nn.Sequential( |
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nn.Linear(n_embd, 4 * n_embd), |
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nn.ReLU(), |
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nn.Linear(4 * n_embd, n_embd), |
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nn.Dropout(dropout), |
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) |
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def forward(self, x): |
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return self.net(x) |
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class Block(nn.Module): |
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def __init__(self, n_embd, n_head): |
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super().__init__() |
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head_size = n_embd // n_head |
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self.sa = MultiHeadAttention(n_head, head_size) |
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self.ffwd = FeedFoward(n_embd) |
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self.ln1 = nn.LayerNorm(n_embd) |
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self.ln2 = nn.LayerNorm(n_embd) |
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def forward(self, x): |
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x = x + self.sa(self.ln1(x)) |
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x = x + self.ffwd(self.ln2(x)) |
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return x |
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class BigramLanguageModel(nn.Module): |
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def __init__(self): |
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super().__init__() |
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self.token_embedding_table = nn.Embedding(vocab_size, n_embd) |
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self.position_embedding_table = nn.Embedding(block_size, n_embd) |
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self.blocks = nn.Sequential(*[Block(n_embd, n_head=n_head) for _ in range(n_layer)]) |
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self.ln_f = nn.LayerNorm(n_embd) |
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self.lm_head = nn.Linear(n_embd, vocab_size) |
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def forward(self, idx, targets=None): |
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B, T = idx.shape |
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tok_emb = self.token_embedding_table(idx) |
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pos_emb = self.position_embedding_table(torch.arange(T)) |
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x = tok_emb + pos_emb |
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x = self.blocks(x) |
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x = self.ln_f(x) |
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logits = self.lm_head(x) |
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if targets is None: |
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loss = None |
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else: |
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B, T, C = logits.shape |
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logits = logits.view(B*T, C) |
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targets = targets.view(B*T) |
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loss = F.cross_entropy(logits, targets) |
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return logits, loss |
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def generate(self, idx, max_new_tokens): |
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for _ in range(max_new_tokens): |
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idx_cond = idx[:, -block_size:] |
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logits, loss = self(idx_cond) |
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logits = logits[:, -1, :] |
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probs = F.softmax(logits, dim=-1) |
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idx_next = torch.multinomial(probs, num_samples=1) |
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idx = torch.cat((idx, idx_next), dim=1) |
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return idx |
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chars = "\n !$&',-.3:;?ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" |
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itos = { i:ch for i,ch in enumerate(chars) } |
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stoi = { ch:i for i,ch in enumerate(chars) } |
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decode = lambda l: ''.join([itos[i] for i in l]) |
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encode = lambda s: [stoi[c] for c in s] |
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model = BigramLanguageModel() |
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def respond( |
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message, |
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history: list[tuple[str, str]], |
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): |
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messages = [{"role": "system", "content": "Cocaine"}] |
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for val in history: |
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if val[0]: |
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messages.append({"role": "user", "content": val[0]}) |
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if val[1]: |
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messages.append({"role": "assistant", "content": val[1]}) |
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messages.append({"role": "user", "content": message}) |
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response = "" |
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input_txt = encode(message) |
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context = torch.tensor(input_txt).unsqueeze(0) |
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idx = context |
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for _ in range(2000): |
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idx_cond = idx[:, -block_size:] |
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logits = model(idx_cond).logits |
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logits = logits[:, -1, :] |
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probs = F.softmax(logits, dim=-1) |
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idx_next = torch.multinomial(probs, num_samples=1) |
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idx = torch.cat((idx, idx_next), dim=1) |
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yield decode(idx_next[0].tolist()) |
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demo = gr.ChatInterface(respond) |
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if __name__ == "__main__": |
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demo.launch() |