Exercises in Programming Style

Chapter 22

Passive Aggressive

22.1 Constraints

• Every single procedure and function checks the sanity of its arguments and refuses to continue when the arguments are unreasonable, jumping out of the function.
• When calling out other functions, program functions only check for errors if they are in a position to react meaningfully.
• Exception handling occurs at higher levels of function call chains, wherever it is meaningful to do so.

22.2 A Program in this Style

  1 #!/usr/bin/env python
  2 import sys, re, operator, string
  3
  4 #
  5 # The functions
  6 #
  7 def extract_words(path_to_file):
  8 assert(type(path_to_file) is str), "I need a string! I quit!" ...