Daniel Arbuckle's Mastering Python

Defining a context manager as a generator

So how can we write our own context managers? There are two ways.

The simplest is to use the @contextlib.contextmanager decorator on a generator function, as we see in the following example:

When we create a context manager this way, we can write it as one continuous piece of code. We can think of the yield statement as a proxy for the whole code block that the with statement contains.

If this block raises an exception, it will look toward our context manager code as if the yield statement was responsible for raising that exception, so we can wrap it in a try statement to deal with any exceptions that ...