Assigning multiple variables in one line

Question

I am trying to make the Fibonacci sequence I don\'t get why this:

def fibonacci(n):
    f1 = 0
    f2 = 1
    i = 1

    while i < n:
        print(f2)
               


        

Answer 1

In the latter example, the right hand side is evaluated first:

f1, f2 = f2, f1 + f2

So the value of f1 used in the calculation of f2 is the "old" value.

In your code, when you do:

f1 = f2
f2 = f1 + f2

the value of f1 has already changed when you go to evaluate the new value for f2.