I need help understanding a statement

Question

primes = {1: 2, 2: 3, 4: 7, 7:17}
print(primes[primes[4]])

I am unsure why in "print(primes[primes[4]])" primes is called twice.

Any help is appreciated

Answer 1

Because prime[4] is 7 , prime[prime[4]] = prime[7]
prime[7] = 17.