Let's take a short detour to try out some of the tools we've introduced on a slightly larger example. Textbooks typically avoid such pragmatism, especially in the early chapters, but we think it's fun to apply new ideas to practical situations. To avoid getting off the the wrong stylistic foot, we'll need to introduce a few "black-box" components to get the job done, but you'll learn about them in detail later, so don't worry.

We're going to write a longer snippet at the REPL, and briefly introduce the with statement. Our code will fetch some text data for some classic literature from the web using a Python standard library function called urlopen(). Here's the code entered at the REPL in full. We've annotated this code snippet with line numbers to facilitate referring to lines from the explanation:

>>> from urllib.request import urlopen
>>> with urlopen('http://sixty-north.com/c/t.txt') as story:
...     story_words = []
...     for line in story...