transformers/convert_tf_checkpoint_to_pytorch.py
2018-11-06 17:47:03 +01:00

110 lines
3.6 KiB
Python

# coding=utf-8
# Copyright 2018 The HugginFace Inc. team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Convert BERT checkpoint."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import re
import argparse
import tensorflow as tf
import torch
import numpy as np
from modeling import BertConfig, BertModel
def convert(config_path, ckpt_path, out_path=None):
# Initialise PyTorch model
config = BertConfig.from_json_file(config_path)
model = BertModel(config)
# Load weights from TF model
path = ckpt_path
print("Converting TensorFlow checkpoint from {}".format(path))
init_vars = tf.train.list_variables(path)
names = []
arrays = []
for name, shape in init_vars:
print("Loading {} with shape {}".format(name, shape))
array = tf.train.load_variable(path, name)
print("Numpy array shape {}".format(array.shape))
names.append(name)
arrays.append(array)
for name, array in zip(names, arrays):
name = name[5:] # skip "bert/"
print("Loading {}".format(name))
name = name.split('/')
if name[0] in ['redictions', 'eq_relationship']:
print("Skipping")
continue
pointer = model
for m_name in name:
if re.fullmatch(r'[A-Za-z]+_\d+', m_name):
l = re.split(r'_(\d+)', m_name)
else:
l = [m_name]
if l[0] == 'kernel':
pointer = getattr(pointer, 'weight')
else:
pointer = getattr(pointer, l[0])
if len(l) >= 2:
num = int(l[1])
pointer = pointer[num]
if m_name[-11:] == '_embeddings':
pointer = getattr(pointer, 'weight')
elif m_name == 'kernel':
array = np.transpose(array)
try:
assert pointer.shape == array.shape
except AssertionError as e:
e.args += (pointer.shape, array.shape)
raise
pointer.data = torch.from_numpy(array)
# Save pytorch-model
if out_path is not None:
torch.save(model.state_dict(), out_path)
return model
if __name__ == "__main__":
parser = argparse.ArgumentParser()
## Required parameters
parser.add_argument("--tf_checkpoint_path",
default=None,
type=str,
required=True,
help="Path the TensorFlow checkpoint path.")
parser.add_argument("--bert_config_file",
default=None,
type=str,
required=True,
help="The config json file corresponding to the pre-trained BERT model. \n"
"This specifies the model architecture.")
parser.add_argument("--pytorch_dump_path",
default=None,
type=str,
required=False,
help="Path to the output PyTorch model.")
args = parser.parse_args()
print(args)
convert(args.bert_config_file, args.tf_checkpoint_path, args.pytorch_dump_path)