subword-nmt/subword_nmt/segment_char_ngrams.py
2018-07-18 07:36:11 +10:00

95 lines
3.3 KiB
Python
Executable File

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: Rico Sennrich
from __future__ import unicode_literals, division
import sys
import codecs
import argparse
# hack for python2/3 compatibility
from io import open
argparse.open = open
def create_parser(subparsers=None):
if subparsers:
parser = subparsers.add_parser('segment-char-ngrams',
formatter_class=argparse.RawDescriptionHelpFormatter,
description="segment rare words into character n-grams")
else:
parser = argparse.ArgumentParser(
formatter_class=argparse.RawDescriptionHelpFormatter,
description="segment rare words into character n-grams")
parser.add_argument(
'--input', '-i', type=argparse.FileType('r'), default=sys.stdin,
metavar='PATH',
help="Input file (default: standard input).")
parser.add_argument(
'--vocab', type=argparse.FileType('r'), metavar='PATH',
required=True,
help="Vocabulary file.")
parser.add_argument(
'--shortlist', type=int, metavar='INT', default=0,
help="do not segment INT most frequent words in vocabulary (default: '%(default)s')).")
parser.add_argument(
'-n', type=int, metavar='INT', default=2,
help="segment rare words into character n-grams of size INT (default: '%(default)s')).")
parser.add_argument(
'--output', '-o', type=argparse.FileType('w'), default=sys.stdout,
metavar='PATH',
help="Output file (default: standard output)")
parser.add_argument(
'--separator', '-s', type=str, default='@@', metavar='STR',
help="Separator between non-final subword units (default: '%(default)s'))")
return parser
def segment_char_ngrams(args):
vocab = [line.split()[0] for line in args.vocab if len(line.split()) == 2]
vocab = dict((y,x) for (x,y) in enumerate(vocab))
for line in args.input:
for word in line.split():
if word not in vocab or vocab[word] > args.shortlist:
i = 0
while i*args.n < len(word):
args.output.write(word[i*args.n:i*args.n+args.n])
i += 1
if i*args.n < len(word):
args.output.write(args.separator)
args.output.write(' ')
else:
args.output.write(word + ' ')
args.output.write('\n')
if __name__ == '__main__':
# python 2/3 compatibility
if sys.version_info < (3, 0):
sys.stderr = codecs.getwriter('UTF-8')(sys.stderr)
sys.stdout = codecs.getwriter('UTF-8')(sys.stdout)
sys.stdin = codecs.getreader('UTF-8')(sys.stdin)
else:
sys.stderr = codecs.getwriter('UTF-8')(sys.stderr.buffer)
sys.stdout = codecs.getwriter('UTF-8')(sys.stdout.buffer)
sys.stdin = codecs.getreader('UTF-8')(sys.stdin.buffer)
parser = create_parser()
args = parser.parse_args()
if sys.version_info < (3, 0):
args.separator = args.separator.decode('UTF-8')
# read/write files as UTF-8
args.vocab = codecs.open(args.vocab.name, encoding='utf-8')
if args.input.name != '<stdin>':
args.input = codecs.open(args.input.name, encoding='utf-8')
if args.output.name != '<stdout>':
args.output = codecs.open(args.output.name, 'w', encoding='utf-8')
segment_char_ngrams(args)