A string identifier is attached to every function at creation time

• Which is nice for debug:

>>> dance.__name__
'dance'

Functions capture local state

• Just like JavaScript, (lexical) closure:
• A closure remembers the values from its enclosing scope when it was created

To check whether something is callable

• Objects can be made callable, by being assigned function as value
• So, to check whether an object is callable:

>>> callable(foo)
True/False

Benefit of functions being first class

• We are able to abstract and pass around behaviours

2 Errors that were painful to debug.

And, what is the difference between raising normal errors and assertions? Basically: