The structure of the talk will be based on taking increasingly large snippets of normal-looking code and translating them into not-so-normal comprehension monsters.

And I promise you it’s a good idea. As an example, that’ll give us the chance to cover:

• How to use multiple loops in one comprehensions!

E.g.: do you know the difference between [[x+y for y in range(10)] for x in range(10)] and [x+y for y in range(10) for x in range(10)]?

• How to use generator comprehension!

E.g.: do you know what happens if you remove the [] from sum([x for x in range(10)])? Does it still work?

• How to know what happens when you use the walrus operator, featuring examples that stumped even expert pythonistas!

E.g.: are the following lines correct? If not, how could you fix them?

function(function := print)

assert ((value := 5) if value else 3) == 5

print(*[value := x for x in range(5)], sep=str(value))

• How to use the dict comprehension!

E.g.: would you be able to re-implement all built-in dictionary operations as one-liners?

• Review of how or and and can be used in expressions and why they can confuse you or make the code clear!

E.g.: what’s the value of a after executing the following line?

((a := 5) and (a := 0) or (a := a + 1)) and ((a := a + 1) and (a - 2) and (a := 5))

And so on. Yes, all of these are examples constructed to be intentionally obscure; but being able to see through them will be very useful as soon as you’ll meet some unintentionally obscure legacy code.