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# On None

Python has a special value, called `None`, that it often uses to tell
you that it cannot give you a valid value.  Unlike any other common
value in Python, if an expression evaluates to `None`, Python shows
you nothing at all for the value, in the notebook, or in an
interactive Python console.

```{python}
my_value = None
my_value
```

```{python}
# This next line is an expression, evaluating to None
None
```

We can see if we got the value `None` by using the `is` comparison operator.  Here is an expression, using the `is` operator, that evaluates to True.

```{python}
my_value is None
```
