I/O, streams, and requests

I/O stands for input/output, and it broadly refers to the communication between a computer and the outside world. There are several different types of I/O, and it is outside the scope of this chapter to explain all of them, but it's worth going through a couple of examples. The first one will introduce the io.StringIO class, which is an in-memory stream for text I/O. The second one instead will escape the locality of our computer, and demonstrate how to perform an HTTP request.

Using an in-memory stream

In-memory objects can be useful in a multitude of situations. Memory is much faster than a disk, it's always available, and for small amounts of data can be the perfect choice.

Let's see the first example:

# io_examples/string_io.py
import io
stream = io.StringIO()
stream.write('Learning Python Programming.\n')
print('Become a Python ninja!', file=stream)
contents = stream.getvalue()
print...