By now, you should be fairly comfortable with organizing your Python code into modules and then importing and using these modules in other modules and programs. This is only a taste of what can be done, however. Let's briefly review what Python modules and packages are before looking closer at how they work.
As we have seen, a module is simply a Python source file. You can import the module using the import statement:
import my_module
Once this is done, you can refer to any functions, classes, variables, and other definitions within the module by prepending the module name to the item, for example:
my_module.do_something() print(my_module.variable)
In Chapter 1, Introducing Modular Programming, we learned that a Python package is a directory containing a special file named __init__.py. This is called the
package initialization file and identifies the directory as a Python package. The package also typically contains one or more Python modules, for example:
