Errors in software code are sometimes referred to as bugs. Debugging is the process of finding and fixing bugs in code. This process can be performed at varying degrees of sophistication. The most efficient way is to use a tool called debugger. Having unittests in place is a good way to identify errors early, refer section Using unittest of Chapter 13, Testing. When it is not obvious where or what the problem is, a debugger is very useful.
There are typically two kinds of bugs:
- An exception is raised and not caught.
- The code does not function properly.
The first case is usually easier to fix. The second can be more difficult as the problem can be a faulty idea or solution, a faulty implementation, or a combination of the two.
We are only concerned with the first case in what follows, but the same tools can be used to help find why the code does not do what it is supposed to.