DeepLearningExamples/PyTorch/Translation/Transformer/scripts/build_sym_alignment.py
2019-01-23 17:03:45 +01:00

99 lines
3.7 KiB
Python

# Copyright (c) 2017-present, Facebook, Inc.
# All rights reserved.
#
# This source code is licensed under the license found in the LICENSE file in
# the root directory of this source tree. An additional grant of patent rights
# can be found in the PATENTS file in the same directory.
#
"""
Use this script in order to build symmetric alignments for your translation
dataset.
This script depends on fast_align and mosesdecoder tools. You will need to
build those before running the script.
fast_align:
github: http://github.com/clab/fast_align
instructions: follow the instructions in README.md
mosesdecoder:
github: http://github.com/moses-smt/mosesdecoder
instructions: http://www.statmt.org/moses/?n=Development.GetStarted
The script produces the following files under --output_dir:
text.joined - concatenation of lines from the source_file and the
target_file.
align.forward - forward pass of fast_align.
align.backward - backward pass of fast_align.
aligned.sym_heuristic - symmetrized alignment.
"""
import argparse
import os
from itertools import zip_longest
def main():
parser = argparse.ArgumentParser(description='symmetric alignment builer')
parser.add_argument('--fast_align_dir',
help='path to fast_align build directory')
parser.add_argument('--mosesdecoder_dir',
help='path to mosesdecoder root directory')
parser.add_argument('--sym_heuristic',
help='heuristic to use for symmetrization',
default='grow-diag-final-and')
parser.add_argument('--source_file',
help='path to a file with sentences '
'in the source language')
parser.add_argument('--target_file',
help='path to a file with sentences '
'in the target language')
parser.add_argument('--output_dir',
help='output directory')
args = parser.parse_args()
fast_align_bin = os.path.join(args.fast_align_dir, 'fast_align')
symal_bin = os.path.join(args.mosesdecoder_dir, 'bin', 'symal')
sym_fast_align_bin = os.path.join(
args.mosesdecoder_dir, 'scripts', 'ems',
'support', 'symmetrize-fast-align.perl')
# create joined file
joined_file = os.path.join(args.output_dir, 'text.joined')
with open(args.source_file, 'r') as src, open(args.target_file, 'r') as tgt:
with open(joined_file, 'w') as joined:
for s, t in zip_longest(src, tgt):
print('{} ||| {}'.format(s.strip(), t.strip()), file=joined)
bwd_align_file = os.path.join(args.output_dir, 'align.backward')
# run forward alignment
fwd_align_file = os.path.join(args.output_dir, 'align.forward')
fwd_fast_align_cmd = '{FASTALIGN} -i {JOINED} -d -o -v > {FWD}'.format(
FASTALIGN=fast_align_bin,
JOINED=joined_file,
FWD=fwd_align_file)
assert os.system(fwd_fast_align_cmd) == 0
# run backward alignment
bwd_align_file = os.path.join(args.output_dir, 'align.backward')
bwd_fast_align_cmd = '{FASTALIGN} -i {JOINED} -d -o -v -r > {BWD}'.format(
FASTALIGN=fast_align_bin,
JOINED=joined_file,
BWD=bwd_align_file)
assert os.system(bwd_fast_align_cmd) == 0
# run symmetrization
sym_out_file = os.path.join(args.output_dir, 'aligned')
sym_cmd = '{SYMFASTALIGN} {FWD} {BWD} {SRC} {TGT} {OUT} {HEURISTIC} {SYMAL}'.format(
SYMFASTALIGN=sym_fast_align_bin,
FWD=fwd_align_file,
BWD=bwd_align_file,
SRC=args.source_file,
TGT=args.target_file,
OUT=sym_out_file,
HEURISTIC=args.sym_heuristic,
SYMAL=symal_bin
)
assert os.system(sym_cmd) == 0
if __name__ == '__main__':
main()