Tensorflow keras GPT 2 pythonサンプルコード解説

!pip install -q keras-nlp

import keras_nlp
import tensorflow as tf
from tensorflow import keras
import time

# To speed up training and generation, we use preprocessor of length 128
# instead of full length 1024.
preprocessor = keras_nlp.models.GPT2CausalLMPreprocessor.from_preset(
    "gpt2_base_en",
    sequence_length=128,
)
gpt2_lm = keras_nlp.models.GPT2CausalLM.from_preset(
    "gpt2_base_en", preprocessor=preprocessor
)

start = time.time()

output = gpt2_lm.generate("My trip to Yosemite was", max_length=200)
print("\nGPT-2 output:")
print(output)

end = time.time()
print(f"TOTAL TIME ELAPSED: {end - start:.2f}s")

GPT-2 output:
My trip to Yosemite was one of the best experiences of my life. I was so close to the top of the mountains, I could feel the sun shining through my eyes. I was so close to the top of the mountains, the sun had a nice view of the valley and I couldn't believe the sun came out of nowhere. The sun shone in all directions and I could feel it. I was so close to the top of the mountains, it felt like I was in the middle of a volcano. It was amazing to see all of that. I felt like a volcano. I felt so close to all of the things. I felt like an island in a sea of lava.

start = time.time()

output = gpt2_lm.generate("That Italian restaurant is", max_length=200)
print("\nGPT-2 output:")
print(output)

end = time.time()
print(f"TOTAL TIME ELAPSED: {end - start:.2f}s")

GPT-2 output:
That Italian restaurant is now closed, according to a report from Bloomberg.

import tensorflow_datasets as tfds

reddit_ds = tfds.load("reddit_tifu", split="train", as_supervised=True)

for document, title in reddit_ds:
    print(document.numpy())
    print(title.numpy())
    break

b"me and a friend decided to go to the beach last sunday. we loaded up and headed out. we were about half way there when i decided that i was not leaving till i had seafood. \n\nnow i'm not talking about red lobster. no friends i'm talking about a low country boil. i found the restaurant and got directions. i don't know if any of you have heard about the crab shack on tybee island but let me tell you it's worth it. \n\nwe arrived and was seated quickly. we decided to get a seafood sampler for two and split it. the waitress bought it out on separate platters for us. the amount of food was staggering. two types of crab, shrimp, mussels, crawfish, andouille sausage, red potatoes, and corn on the cob. i managed to finish it and some of my friends crawfish and mussels. it was a day to be a fat ass. we finished paid for our food and headed to the beach. \n\nfunny thing about seafood. it runs through me faster than a kenyan \n\nwe arrived and walked around a bit. it was about 45min since we arrived at the beach when i felt a rumble from the depths of my stomach. i ignored it i didn't want my stomach to ruin our fun. i pushed down the feeling and continued. about 15min later the feeling was back and stronger than before. again i ignored it and continued. 5min later it felt like a nuclear reactor had just exploded in my stomach. i started running. i yelled to my friend to hurry the fuck up. \n\nrunning in sand is extremely hard if you did not know this. we got in his car and i yelled at him to floor it. my stomach was screaming and if he didn't hurry i was gonna have this baby in his car and it wasn't gonna be pretty. after a few red lights and me screaming like a woman in labor we made it to the store. \n\ni practically tore his car door open and ran inside. i ran to the bathroom opened the door and barely got my pants down before the dam burst and a flood of shit poured from my ass. \n\ni finished up when i felt something wet on my ass. i rubbed it thinking it was back splash. no, mass was covered in the after math of me abusing the toilet. i grabbed all the paper towels i could and gave my self a whores bath right there. \n\ni sprayed the bathroom down with the air freshener and left. an elderly lady walked in quickly and closed the door. i was just about to walk away when i heard gag. instead of walking i ran. i got to the car and told him to get the hell out of there."
b'liking seafood'

train_ds = train_ds.take(500)
num_epochs = 1

# Linearly decaying learning rate.
learning_rate = keras.optimizers.schedules.PolynomialDecay(
    5e-5,
    decay_steps=train_ds.cardinality() * num_epochs,
    end_learning_rate=0.0,
)
loss = keras.losses.SparseCategoricalCrossentropy(from_logits=True)
gpt2_lm.compile(
    optimizer=keras.optimizers.Adam(learning_rate),
    loss=loss,
    weighted_metrics=["accuracy"],
)

gpt2_lm.fit(train_ds, epochs=num_epochs)

start = time.time()

output = gpt2_lm.generate("I like basketball", max_length=200)
print("\nGPT-2 output:")
print(output)

end = time.time()
print(f"TOTAL TIME ELAPSED: {end - start:.2f}s")

GPT-2 output:
I like basketball. i've been a big fan of it since high school, and it's been pretty cool to me.

# Use a string identifier.
gpt2_lm.compile(sampler="top_k")
output = gpt2_lm.generate("I like basketball", max_length=200)
print("\nGPT-2 output:")
print(output)

# Use a `Sampler` instance. `GreedySampler` tends to repeat itself,
greedy_sampler = keras_nlp.samplers.GreedySampler()
gpt2_lm.compile(sampler=greedy_sampler)

output = gpt2_lm.generate("I like basketball", max_length=200)
print("\nGPT-2 output:")
print(output)

!# Load chinese poetry dataset.
!git clone https://github.com/chinese-poetry/chinese-poetry.git

import os
import json

poem_collection = []
for file in os.listdir("chinese-poetry/全唐诗"):
    if ".json" not in file or "poet" not in file:
        continue
    full_filename = "%s/%s" % ("chinese-poetry/全唐诗", file)
    with open(full_filename, "r") as f:
        content = json.load(f)
        poem_collection.extend(content)

paragraphs = ["".join(data["paragraphs"]) for data in poem_collection]

print(paragraphs[0])

train_ds = (
    tf.data.Dataset.from_tensor_slices(paragraphs)
    .batch(16)
    .cache()
    .prefetch(tf.data.AUTOTUNE)
)

# Running through the whole dataset takes long, only take `500` and run 1
# epochs for demo purposes.
train_ds = train_ds.take(500)
num_epochs = 1

learning_rate = keras.optimizers.schedules.PolynomialDecay(
    5e-4,
    decay_steps=train_ds.cardinality() * num_epochs,
    end_learning_rate=0.0,
)
loss = keras.losses.SparseCategoricalCrossentropy(from_logits=True)
gpt2_lm.compile(
    optimizer=keras.optimizers.Adam(learning_rate),
    loss=loss,
    weighted_metrics=["accuracy"],
)

gpt2_lm.fit(train_ds, epochs=num_epochs)

output = gpt2_lm.generate("昨夜雨疏风骤", max_length=200)
print(output)