IBM developerWorks: Python 101: Testing your code, Discover PythonUnit, a Unit Testing FrameworkJan 09, 2000, 15:45 (0 Talkback[s])
(Other stories by Evelyn Mitchell)
"New developerWorks columnist Evelyn Mitchell follows up her first Python article, which introduced you to the Python programming language. In this installment, Evelyn explains the virtues of unit testing as you write a program, and looks at PythonUnit, a testing tool, using some short sample programs to illustrate the tool and further expose you to programming with Python...."
"Unit testing is the process of testing code as you write it. You can also use unit testing during regression testing, in which you determine if a program is working the way it did before you modified it. Unit testing is also known as "white box" or "glass box testing," as opposed to "black box testing."
"Black box testing is, roughly speaking, testing done by someone who does not have access to the program's code. In black box testing the program is viewed (you might have guessed) as a black box that takes inputs and produces outputs, but doesn't reveal its internal structure. By contrast, unit testing exercises your full knowledge of the code by testing the interfaces to other code components and to user space, as well as the implementation."