Wikipedia Processing

Posted 2021-03-14 fengyubo

Wikipedia Processing

For Chinese, https://dumps.wikimedia.org/zhwiki/latest/

zhwiki-latest-pages-articles.xml.bz2

For English, https://dumps.wikimedia.org/enwiki/latest/

enwiki-latest-pages-articles.xml.bz2

Chinese

Processing by following order:

1. Extraction
2. Convert Traditional Chinese to Simplified Chinese
3. Keep in utf-8 characters
4. keep in Chinese characters
5. Segmentation

Extraction

Extracting plain text from zhwiki-20200101-pages-articles.xml.bz2 by following code.

# encoding:utf8

import sys
from gensim.corpora import WikiCorpus
from tqdm import tqdm


if __name__ == '__main__':
    if len(sys.argv) < 3:
        print('Usage: python3 wikipedia_extraction.py wikipedia.xml.bz2 wikipedia.txt')
    file_name = sys.argv[1:]

    fo = open(file_name[1], encoding='utf8', mode='w')
    wiki = WikiCorpus(fname=file_name[0], lemmatize=False, dictionary=dict())
    for article in tqdm(wiki.get_texts()):
        for sentence in article:
            fo.write("%s" % sentence)
        fo.write("
")

Converting

To convert Traditional Chinese to Simplified Chinese by following bash command.

opencc -i wikipedia.zh.txt -o wikipedia.zhs.txt -c t2s.json

t2s.json obtained from https://github.com/BYVoid/OpenCC/blob/master/data/config/t2s.json , but we can see it as follow.

{
  "name": "Traditional Chinese to Simplified Chinese",
  "segmentation": {
    "type": "mmseg",
    "dict": {
      "type": "ocd",
      "file": "TSPhrases.ocd"
    }
  },
  "conversion_chain": [{
    "dict": {
      "type": "group",
      "dicts": [{
        "type": "ocd",
        "file": "TSPhrases.ocd"
      }, {
        "type": "ocd",
        "file": "TSCharacters.ocd"
      }]
    }
  }]
}

Keep utf-8

To use following bash command to keep utf-8 characters in.

iconv -c -t UTF-8 -o wikipedia.zhs.utf8.txt wikipedia.zhs.txt

Keep Chinese

Keeping only Chinese characters in corpus by following code.

# encoding:utf8
# Filter out un-Chinese characters

import sys
from tqdm import tqdm


if __name__ == '__main__':
    if len(sys.argv) < 3:
        print("Usage: python3 wikipedia.zhs.utf8.txt wikipedia.zhs.utf8.chi.txt")
        exit(1)

    fout = open(sys.argv[2], encoding='utf8', mode='w')
    with open(sys.argv[1], encoding='utf8') as fin:
        for line in tqdm(fin):
            for word in line:
                for char in word:
                    if char == ' ' or char == '
':
                        fout.write(char)
                    if char >= u'u4e00' and char <= u'u9fa5':  # is a Chinese character
                        fout.write(char)

Segmentation

To segment corpus by following code. This is a simple segmentation program.

# encoding:utf8
# Just a simple segmentation program

import sys
import jieba
from tqdm import tqdm


def sentences(fpath):
    with open(fpath, encoding='utf8') as f:
        for line in f:
            yield line.strip()


if __name__ == '__main__':
    if len(sys.argv) < 3:
        print("Usage: python3 SimSeg.py in-path out-path")
        exit(1)

    jieba.initialize()
    f = open(sys.argv[2], encoding='utf8', mode='w')
    for sentence in tqdm(sentences(sys.argv[1])):
        words = list(jieba.cut(sentence, cut_all=False))
        while ' ' in words:
            words.remove(" ")
        f.write("%s
" % " ".join(words))