User:Wei2912

From Apertium
Jump to navigation Jump to search

My name is Wei En and I'm currently a GCI student. My blog is at http://wei2912.github.io.

I decided to help out at Apertium because I find the work here quite interesting and I believe Apertium will benefit many.

The following are projects related to Apertium.

Wiktionary Crawler

https://github.com/wei2912/WiktionaryCrawler is a crawler for Wiktionary which aims to extract data from pages. It was created for a GCI task which you can read about at Task ideas for Google Code-in/Scrape inflection information from Wiktionary.

The crawler crawls a starting category (usually Category:XXX language)for subcategories, then crawls these subcategories for pages. It then passes the page to language-specific parsers which turn it into the Speling format.

The current languages supported are Chinese (zh), Thai (th) and Lao (lo). You are welcome to contribute to this project.

Spaceless Segmentation

Spaceless Segmentation has been merged into Apertium under https://svn.code.sf.net/p/apertium/svn/branches/tokenisation. It serves to tokenize languages without any whitespace. More information can be found under Task ideas for Google Code-in/Tokenisation for spaceless orthographies.

The tokeniser looks for possible tokenisations in the corpus text and selects the tokenisation which tokens appears the most in corpus.

A report comparing the above method, LRLM and RLLM (longest left to right matching and longest right to left matching respectively) is available at https://www.dropbox.com/sh/57wtof3gbcbsl7c/AABI-Mcw2E-c942BXxsMbEAja

Conversion of PDF dictionary to lttoolbox format

NOTE: This document is a draft.

In this example we're converting the following PDF file: http://home.uchicago.edu/straughn/sakhadic.pdf

We copy the text directly from the PDF file, as PDF to text converters are currently unable to convert the text properly (thanks to the arcane PDF format).

Then, we pipe the text to our script:

#!/usr/bin/python3
# -*- coding: utf-8 -*-

import fileinput
import itertools
import re
import xml.etree.cElementTree as ET

BRACKETS_RE = re.compile(r'(\(.+?\)|\[.+?\])')
PAGENUMBER_RE = re.compile(r'^\d+$')
SPLIT_RE = re.compile(r'[;,]\s+')

ABBRVS = {
    'a.': ['adj'],
    'adv.': ['adv'],
    # arch. archaic
    # cf. see also
    # comp. computer-related
    # conv. converb, modifying verb
    # dial. dialect
    'det.': ['det'],
    # Evk. Evenki
    'exc.': ['ij'],
    'int.': ['itg'],
    # Mongo. Mongolian
    'n.': ['n'],
    'num.': ['det', 'qnt'],
    # ono. onomatopoeia
    'pl.': ['pl'],
    'pp.': ['post'],
    'pro.': ['prn'],
    # Russ. Russian
    'v.': ['v', 'TD']
}

def insert_blanks(element, line):
    words = line.split()
    if not words:
        return
    element.text = words[0]
    element.tail = None
    blank = None
    for i in words[1:]:
        blank = ET.SubElement(element, 'b')
        blank.tail = i

def is_page_num(line):
    return PAGENUMBER_RE.match(line)

def strip_brackets(line):
    brackets = BRACKETS_RE.search(line)
    if brackets:
        for bracket in brackets.groups():
            line.replace(bracket, "")
    return line

class Entry(object):
    def __split(self, line):
        return SPLIT_RE.split(line)

    def __init__(self, line):
        tags = line.split()

        self.words = []
        self.abbrvs = []
        self.meanings = []

        found_abbrv = False
        found_conv = False
        for tag in tags:
            if tag in ABBRVS.keys(): # abbreviations
                found_abbrv = True
                self.abbrvs.extend(ABBRVS[tag])
                continue
            elif tag == "conv.":
                found_abbrv = True
                found_conv = True
                self.abbrvs.append("vaux")
                continue

            if not found_abbrv: # entrys
                self.words.append(tag)
            else: # translated
                self.meanings.append(tag)

        # if there's "cf" in a word, we trim off everything else
        for i, word in enumerate(self.words):
            if word == "cf":
                self.words = self.words[:i]

        # if there's a converb, just look at the last word
        if found_conv:
            self.words = self.words[-1]
        else:
            self.words = " ".join(self.words)
        self.meanings = " ".join(self.meanings)

        self.words = strip_brackets(self.words)
        self.meanings = strip_brackets(self.meanings)

        if not self.abbrvs:
            self.words = None
            self.abbrvs = None
            self.meanings = None
            return

        # preprocessing meanings
        self.meanings = self.meanings.replace("to", "")

        # split up meanings and entrys
        self.words = [x.strip() for x in self.__split(self.words)]
        self.meanings = [x.strip() for x in self.__split(self.meanings)]

def is_cyrillic(word):
    num_non_cyrillic = 0
    num_cyrillic = 0
    for c in word:
        ordc = ord(c)
        if 0x0400 <= ordc <= 0x04FF:
            num_cyrillic += 1
        else:
            num_non_cyrillic += 1
    return num_cyrillic > num_non_cyrillic

def preprocess(lines):
    new_lines = []
    for i, line in enumerate(lines):
        line = lines[i]
        if not line:
            continue
        line = line.strip()
        line = line.replace("•", "")
        line = line.replace("=", "")
        line = line.replace("cf.", "cf")

        if not line or is_page_num(line):
            continue

        # check if next line should be merged with this line
        if i+1 < len(lines):
            words = line.split()
            if (len(words) == 1 or
                not is_cyrillic(lines[i+1].split()[0])):
                lines[i+1] = line + " " + lines[i+1]
                continue

        orig_word = ""
        for j, word in enumerate(words):
            if j+1 >= len(words):
                continue
            next_word = words[j+1]

            if word.endswith("."):
                orig_word = " ".join(words[:j])
            
            if word.endswith(";"):
                # if semicolon seperates dictionary entries
                if is_cyrillic(next_word):
                    words[j] = word.replace(";", "")
                    line = " ".join(words[:j+1])
                    next_line = " ".join(words[j+1:])
                    lines.insert(i+1, next_line)
                    break
                # if semicolon seperates abbreviations
                elif next_word.endswith("."):
                    words[j] = word.replace(";", "")
                    line = " ".join(words[:j+1])
                    next_line = orig_word + " " + " ".join(words[j+1:])
                    lines.insert(i+1, next_line)
                    break

        line = line.strip()
        if line:
            new_lines.append(line)
    return new_lines

def main():
    dictionary = ET.Element("dictionary")
    pardefs = ET.SubElement(dictionary, "pardefs")

    lines = list(fileinput.input())
    new_lines = preprocess(lines)

    for line in new_lines:
        comment = ET.Comment(text=line)
        pardefs.append(comment)

        entry = Entry(line)
        if not (entry.words and entry.abbrvs and entry.meanings):
            continue

        for word, meaning in itertools.product(entry.words, entry.meanings):
            e = ET.SubElement(pardefs, "e")
            e.set('r', 'LR')

            p = ET.SubElement(e, 'p')

            # add word and meaning
            left = ET.SubElement(p, 'l')
            insert_blanks(left, word)

            right = ET.SubElement(p, 'r')
            insert_blanks(right, meaning)

            # add abbreviations
            for abbrv in entry.abbrvs:
                s = ET.Element('s')
                s.set('n', abbrv)
                left.append(s)
                right.append(s)
    ET.dump(dictionary)

main()

This will give us a XML dump of the dictionary, converted to the lttoolbox format. We format the XML file as shown here:

$ xmllint --format --encode utf8 file.xml > file.dix

The `--encode utf8` option prevents `xmllint` from escaping our unicode.

The final file format looks like this:

<?xml version="1.0" encoding="utf-8"?>
<dictionary>
  <pardefs>
    <!--аа exc. Oh! See!-->
    <e r="LR">
      <p>
        <l>аа<s n="ij"/></l>
        <r>Oh!<b/>See!<s n="ij"/></r>
      </p>
    </e>
    <!--ааҕыс v. to reckon with-->
    <e r="LR">
      <p>
        <l>ааҕыс<s n="v"/><s n="TD"/></l>
        <r>reckon<b/>with<s n="v"/><s n="TD"/></r>
      </p>
    </e>
    <!--аайы a. each, every-->
    <e r="LR">
      <p>
        <l>аайы<s n="adj"/></l>
        <r>each<s n="adj"/></r>
      </p>
    </e>
    <e r="LR">
      <p>
        <l>аайы<s n="adj"/></l>
        <r>every<s n="adj"/></r>
      </p>
    </e>
    <!--күн аайы every day-->
    <!--аак cf аах n. document, paper-->
    <e r="LR">
      <p>
        <l>аак<s n="n"/></l>
        <r>document<s n="n"/></r>
      </p>
    </e>
    <e r="LR">
      <p>
        <l>аак<s n="n"/></l>
        <r>paper<s n="n"/></r>
      </p>
    </e>
...