text: #!/usr/bin/python3
  import sys, re, operator, string
  
  #
  # The functions
  #
  def extract_words(path_to_file):
      assert(type(path_to_file) is str), "I need a string! I quit!" 
      assert(path_to_file), "I need a non-empty string! I quit!" 
  
      with open(path_to_file) as f:
          data = f.read()
      pattern = re.compile('[\W_]+')
      word_list = pattern.sub(' ', data).lower().split()
      return word_list
  
  def remove_stop_words(word_list):
      assert(type(word_list) is list), "I need a list! I quit!"
  
      with open('../stop_words.txt') as f:
          stop_words = f.read().split(',')
      # add single-letter words
      stop_words.extend(list(string.ascii_lowercase))
      return [w for w in word_list if not w in stop_words]
  
  def frequencies(word_list):
      assert(type(word_list) is list), "I need a list! I quit!"
      assert(word_list != []), "I need a non-empty list! I quit!"
  
      word_freqs = {}
      for w in word_list:
          if w in word_freqs:
              word_freqs[w] += 1
          else:
              word_freqs[w] = 1
      return word_freqs
  
  def sort(word_freqs):
      assert(type(word_freqs) is dict), "I need a dictionary! I quit!"
      assert(word_freqs != {}), "I need a non-empty dictionary! I quit!"
  
      return sorted(word_freqs.items(), key=operator.itemgetter(1), reverse=True)
  
  #
  # The main function
  #
  try:
      assert(len(sys.argv) > 1), "You idiot! I need an input file! I quit!"
      word_freqs = sort(frequencies(remove_stop_words(extract_words(sys.argv[1]))))
  
      assert(len(word_freqs) > 25), "OMG! Less than 25 words! I QUIT!"
      for tf in word_freqs[0:25]:
          print(tf[0], '-', tf[1])
  except Exception as e:
          print("Something wrong: {0}".format(e))
  
  
  