title: is it possible to use dir of bzip files as a corpus
body: <p>I'm trying to use a directory with text in .bz2 files :</p>
  <pre><code>def as_corpus(path, name): return nltk.corpus.PlaintextCorpusReader(path,name)
  
  corpus = as_corpus(corpus_dir, r'.*\.bz2')
  </code></pre>
  <p>but getting :</p>
  <pre><code>  File &quot;/usr/lib/python3.8/encodings/utf_8.py&quot;, line 16, in decode
      return codecs.utf_8_decode(input, errors, True)
  UnicodeDecodeError: 'utf-8' codec can't decode byte 0xee in position 12: invalid continuation byte
  </code></pre>