This lecture looks at the basics of testing software.

1. Introduction (pdf, ppt)
   • Why you should do testing
   • Limitations of testing
   • Introduction to unit tests
   • Basic testing pattern
2. Exceptions (pdf, ppt)
   • Causes of errors
   • Error handling via status codes
   • Error handling via exceptions
   • Producing informative error messages
   • Raising your own exceptions
3. Unit Testing (pdf, ppt)
   • Python’s “Nose” library
   • Creating useful test cases
4. Interface and Implementation (pdf, ppt)
   • The difference between “interface” and “implementation”
   • Isolating components for testing
   • Using StringIO instead of external files
   • Important rules for testing
5. Floating Point (pdf, ppt)
   • Storing floating point numbers on computers
   • Mathematical operations in floating point systems
   • Absolute and relative error
   • Floating point numbers in testing
6. Fixtures (pdf, ppt)
   • Why fixtures are useful
   • Creating fixtures using Nose
   • Nose’s “setup” function vs. global variables
   • Using decorators to deal with modified fixtures

Exercises