Python Coding challenge - Day 669| What is the output of the following Python Code?

 

Code Explanation:

Line 1 — Define the Fibonacci function factory

def make_fibonacci():

This defines a function named make_fibonacci that will return another function capable of producing the next Fibonacci number each time it’s called.

Line 2 — Initialize the first two numbers

    a, b = 0, 1

Sets the starting values for the Fibonacci sequence:

a = 0 (first number)

b = 1 (second number)

Line 3 — Define the inner generator function

    def next_num():

Creates an inner function next_num that will update and return the next number in the sequence each time it’s called.

Line 4 — Allow modification of outer variables

        nonlocal a, b

Tells Python that a and b come from the outer function’s scope and can be modified.

Without nonlocal, Python would treat a and b as new local variables inside next_num.

Line 5 — Update to the next Fibonacci numbers

        a, b = b, a + b

The new a becomes the old b (the next number in sequence).

The new b becomes the sum of the old a and old b (Fibonacci rule).

Line 6 — Return the current Fibonacci number

        return a

Returns the new value of a, which is the next number in the sequence.

Line 7 — Return the generator function

    return next_num

Instead of returning a number, make_fibonacci returns the function next_num so it can be called repeatedly to get subsequent numbers.

Line 8 — Create a Fibonacci generator

fib = make_fibonacci()

Calls make_fibonacci() and stores the returned next_num function in fib.

Now, fib() will give the next Fibonacci number each time it’s called.

Line 9 — Generate and print first 7 Fibonacci numbers

print([fib() for _ in range(7)])

[fib() for _ in range(7)] calls fib() seven times, collecting results in a list.

Output:

[1, 1, 2, 3, 5, 8, 13]

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