Testing our reusable package

Now that we've written the code (or alternatively, downloaded it), let's take a look at how this package works. In a terminal window, set the current directory to the folder containing your quantities package directory, and type python to start the Python interpreter. Then, type the following:

>>> import quantities

If you haven't made any mistakes in typing in the source code, the interpreter should come back without any errors. If you have made any typos, you'll need to fix them before you can proceed.

Next, we have to initialize our quantities package by supplying the locale we want to use:

>>> quantities.init("international")

If you are in the United States, feel free to replace the value international with us so that you get localized spelling and units for your country.

Let's create a simple quantity, and then ask the Python interpreter to display it:

>>> q = quantities.new(24, "km")
>>>> print(q)
24 kilometre

As you can...