old_contents: #!/usr/bin/env python
  import sys, re, operator, string, inspect
  
  #
  # The functions
  #
  def read_stop_words():
      # Meta-level data: inspect.stack() and locals()
      print "My name is " + inspect.stack()[0][3] + ", my arguments are " + str(locals().keys())
      print "   and I'm being called from ", inspect.stack()[1][3]
      with open('../stop_words.txt') as f:
          stop_words = f.read().split(',')
      stop_words.extend(list(string.ascii_lowercase))
      return stop_words
  
  def extract_words(path_to_file):
      # Meta-level data: inspect.stack() and locals()
      print "My name is " + inspect.stack()[0][3] + ", my arguments are " + str(locals().keys())
      print "   and I'm being called from ", inspect.stack()[1][3]
      with open(locals()['path_to_file']) as f:
          str_data = f.read()
      pattern = re.compile('[\W_]+')
      word_list = pattern.sub(' ', str_data).lower().split()
      stop_words = read_stop_words()
      return [w for w in word_list if not w in stop_words]
  
  def frequencies(word_list):
      # Meta-level data: inspect.stack() and locals()
      print "My name is " + inspect.stack()[0][3] + ", my arguments are " + str(locals().keys())
      print "   and I'm being called from ", inspect.stack()[1][3]
      word_freqs = {}
      for w in locals()['word_list']:
          if w in word_freqs:
              word_freqs[w] += 1
          else:
              word_freqs[w] = 1
      return word_freqs
  
  def sort(word_freq):
      # Meta-level data: inspect.stack() and locals()
      print "My name is " + inspect.stack()[0][3] + " and my arguments are " + str(locals().keys())
      print "   and I'm being called from ", inspect.stack()[1][3]
      return sorted(locals()['word_freq'].iteritems(), key=operator.itemgetter(1), reverse=True)
  
  #
  # The main function
  #
  def main():
      word_freqs = sort(frequencies(extract_words(sys.argv[1])))
      for (w, c) in word_freqs[0:25]:
          print w, ' - ', c
  
  if __name__ == "__main__":
      main()
  
  
new_contents: #!/usr/bin/env python
  import sys, re, operator, string, inspect
  
  def read_stop_words():
      """ This function can only be called from a function 
          named extract_words."""
      # Meta-level data: inspect.stack()
      if inspect.stack()[1][3] != 'extract_words':
          return None
  
      with open('../stop_words.txt') as f:
          stop_words = f.read().split(',')
      stop_words.extend(list(string.ascii_lowercase))
      return stop_words
  
  def extract_words(path_to_file):
      # Meta-level data: locals()
      with open(locals()['path_to_file']) as f:
          str_data = f.read()
      pattern = re.compile('[\W_]+')
      word_list = pattern.sub(' ', str_data).lower().split()
      stop_words = read_stop_words()
      return [w for w in word_list if not w in stop_words]
  
  def frequencies(word_list):
      # Meta-level data: locals()
      word_freqs = {}
      for w in locals()['word_list']:
          if w in word_freqs:
              word_freqs[w] += 1
          else:
              word_freqs[w] = 1
      return word_freqs
  
  def sort(word_freq):
      # Meta-level data: locals()
      return sorted(locals()['word_freq'].iteritems(), key=operator.itemgetter(1), reverse=True)
  
  def main():
      word_freqs = sort(frequencies(extract_words(sys.argv[1])))
      for (w, c) in word_freqs[0:25]:
          print w, ' - ', c
  
  if __name__ == "__main__":
      main()
  
  
subject: Use introspection more meaningfully