Organizing code into src, bin, and test

As we noted in the previous section, there's no essential need for a complex directory structure. Simple Python applications can be built in a simple, flat directory. We can include the application modules, test modules, as well as setup.py and README. This is pleasantly simple and easy to work with.

When the modules and packages get more complex, however, we'll often need to be a bit more structured. For complex applications, one common approach is to segregate Python code into three bundles. To make the examples concrete, let's assume that our application is called my_app. Here are the typical directories we might create:

• my_app/my_app: This directory has all of the working application code. All of the various modules and packages are here. A vaguely named src directory is uninformative. This my_app directory should include an empty __init__.py file so that the application also acts as a package.

• my_app/bin or my_spp/scripts: This directory can have...