Exercises in Programming Style

Chapter 18

Aspects

18.1 Constraints

• The problem is decomposed using some form of abstraction (procedures, functions, objects, etc.).
• Aspects of the problem are added to the main program without any edits to the source code of the abstractions or the sites that use them.
• An external binding mechanism binds the abstractions with the aspects.

18.2 A Program in this Style

  1 #!/usr/bin/env python
  2 import sys, re, operator, string, time
  3
  4 #
  5 # The functions
  6 #
  7 def extract_words(path_to_file):
  8 with open(path_to_file) as f:
  9  str_data = f.read()
 10 pattern = re.compile('[\W_]+')
 11 word_list = pattern.sub(' ', str_data).lower().split()