On: Python idiom for taking the single item from a list

[statictype]

There's nothing wrong with `is l`. Sounds like you're just splitting hairs.

He's defending against None because calling __len__ on None results in an exception.

3.14159 also results in an exception but it's far more likely that the object passed was None than that it was a completely different type than the one expected.

[jemfinch → statictype]

> it's far more likely that the object passed was None than that it was a completely different type than the one expected.

FYI, None is a completely different type than the one expected.