title: TypeError:__init__() missing 2 required positional arguments
body: <p>I am currently running into this error.
  I don't know what this error is caused by because I've declared the positional arguments <code>path2</code> and  <code>path3</code> already in my code but the error says that this two arguments missing.</p>
  <p><strong>Error Message:</strong><code>TypeError: __init__() missing 2 required positional arguments: 'path2' and 'path3'</code></p>
  <p><strong>This is my code:</strong></p>
  <pre><code>import os
  from tqdm import tqdm
  
  from utils import SOS, EOS, UNK, process
  
  
  class Corpus(object):
      def __init__(self, path, path2, path3, order, lower=False, max_lines=-1):
          self.order = order
          self.lower = lower
          self.max_lines = max_lines
          self.vocab = set()
          self.train = self.tokenize(os.path.join(path), training_set=True)
          self.valid = self.tokenize(os.path.join(path2))
          self.test = self.tokenize(os.path.join(path3))
  
      def tokenize(self, path, training_set=False):
          &quot;&quot;&quot;Tokenizes a text file.&quot;&quot;&quot;
          #assert os.path.exists(path)
          with open(path, path2, path3) as fin:
              num_lines = sum(1 for _ in fin.readlines())
          with open(path, path2, path3, 'r', encoding=&quot;utf8&quot;) as f:
              words = []
              for i, line in enumerate(tqdm(f, total=num_lines)):
                  if self.max_lines &gt; 0 and i &gt; self.max_lines:
                      break
                  line = line.strip()
                  if not line:
                      continue  # Skip empty lines.
                  elif line.startswith('='):
                      continue  # Skip headers.
                  else:
                      sentence = (self.order - 1) * [SOS] + \
                          [process(word, self.lower) for word in line.split()] + [EOS]
                      if training_set:
                          words.extend(sentence)
                          self.vocab.update(sentence)
                      else:
                          sentence = [word if word in self.vocab else UNK for word in sentence]
                          words.extend(sentence)
          return words
  
  
  if __name__ == '__main__':
      path = 'C://Users//supre//Documents//Python Programme//kenlm//wikitext-2//wiki.train.tokens'
      path2 = 'C://Users//supre//Documents//Python Programme//kenlm//wikitext-2//wiki.valid.tokens'
      path3 = 'C://Users//supre//Documents//Python Programme//kenlm//wikitext-2//wiki.test.tokens'
      corpus = Corpus(path, order=3)
      print(len(corpus.test))
      print(corpus.test[:100])
  </code></pre>
  <p>Thank's for every help and suggestion in advance:)</p>