What does zero mean in fib.get(4,0)?

Answer 1

In this example fib.get(4,0) the key 4 is present so it will pass the corresponding value 3 from the dictionary and now fib.get(7,5) the key 7 is not present so it will pass the second argument 5 so answer is 3+5=8

Answer 2

If there wasn't a key 4, assign value 0

Answer 3

That helped a lot. thanks!

Answer 4

thanks a ton Sean T for explaining