I'm really confused on how the answer was 8.

Question

fib = {1: 1, 2: 1, 3: 2, 4: 3}
print(fib.get(4, 0) + fib.get(7, 5))

Answer 1

fib is a dictionary. The .get() method for dictonaries is

dict.get(key[, value])

where get() will return the corresponding value of a specified key, or the optional value argument if the key is not found within the dictionary. E.g.

dict.get(1,39)

will return the value of key 1, or 39, if key 1 is not found in dict. Hence for

fib = {1: 1, 2: 1, 3: 2, 4: 3}

fib.get(4, 0) returns 3 (key 4 is found, value is 3)
fib.get(7, 5)) returns 5 (key 7 not found, returns 5)

3+5 = 8