Sebastian Raschka ffd4035144
Add GPTModelFast (#584)
* Add GPTModelFast

* update
2025-03-27 14:00:25 -05:00

112 lines
3.4 KiB
Python

# Copyright (c) Sebastian Raschka under Apache License 2.0 (see LICENSE.txt).
# Source for "Build a Large Language Model From Scratch"
# - https://www.manning.com/books/build-a-large-language-model-from-scratch
# Code: https://github.com/rasbt/LLMs-from-scratch
from llms_from_scratch.ch02 import create_dataloader_v1
from llms_from_scratch.ch04 import GPTModel, GPTModelFast
from llms_from_scratch.ch05 import train_model_simple
import os
import urllib
import pytest
import tiktoken
import torch
from torch.utils.data import Subset, DataLoader
GPT_CONFIG_124M = {
"vocab_size": 50257,
"context_length": 256, # Shortened for test speed
"emb_dim": 768,
"n_heads": 12,
"n_layers": 12,
"drop_rate": 0.1,
"qkv_bias": False
}
OTHER_SETTINGS = {
"learning_rate": 5e-4,
"num_epochs": 2,
"batch_size": 1,
"weight_decay": 0.1
}
@pytest.mark.parametrize("ModelClass", [GPTModel, GPTModelFast])
def test_train_simple(tmp_path, ModelClass):
torch.manual_seed(123)
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
##############################
# Download data if necessary
##############################
file_path = tmp_path / "the-verdict.txt"
url = "https://raw.githubusercontent.com/rasbt/LLMs-from-scratch/main/ch02/01_main-chapter-code/the-verdict.txt"
if not os.path.exists(file_path):
with urllib.request.urlopen(url) as response:
text_data = response.read().decode("utf-8")
with open(file_path, "w", encoding="utf-8") as f:
f.write(text_data)
else:
with open(file_path, "r", encoding="utf-8") as f:
text_data = f.read()
##############################
# Set up dataloaders
##############################
train_ratio = 0.90
split_idx = int(train_ratio * len(text_data))
train_loader = create_dataloader_v1(
text_data[:split_idx],
batch_size=OTHER_SETTINGS["batch_size"],
max_length=GPT_CONFIG_124M["context_length"],
stride=GPT_CONFIG_124M["context_length"],
drop_last=True,
shuffle=True,
num_workers=0
)
val_loader = create_dataloader_v1(
text_data[split_idx:],
batch_size=OTHER_SETTINGS["batch_size"],
max_length=GPT_CONFIG_124M["context_length"],
stride=GPT_CONFIG_124M["context_length"],
drop_last=False,
shuffle=False,
num_workers=0
)
# Limit to 1 batch for speed
train_subset = Subset(train_loader.dataset, range(1))
one_batch_train_loader = DataLoader(train_subset, batch_size=1)
val_subset = Subset(val_loader.dataset, range(1))
one_batch_val_loader = DataLoader(val_subset, batch_size=1)
##############################
# Train model
##############################
model = ModelClass(GPT_CONFIG_124M)
model.to(device)
optimizer = torch.optim.AdamW(
model.parameters(),
lr=OTHER_SETTINGS["learning_rate"],
weight_decay=OTHER_SETTINGS["weight_decay"]
)
tokenizer = tiktoken.get_encoding("gpt2")
train_losses, val_losses, tokens_seen = train_model_simple(
model, one_batch_train_loader, one_batch_val_loader, optimizer, device,
num_epochs=OTHER_SETTINGS["num_epochs"], eval_freq=1, eval_iter=1,
start_context="Every effort moves you", tokenizer=tokenizer
)
assert round(train_losses[0], 1) == 7.6
assert round(val_losses[0], 1) == 10.1
assert train_losses[-1] < train_losses[0]