#The Fibonacci sequence is a number sequence where each #number is the sum of the previous two numbers. The first #two numbers are defined as 0 and 1, so the third number is #1 (0 + 1 = 1), the fourth number is 2 (1 + 1 = 2), the #fifth number is 3 (1 + 2 = 3), the sixth number is 5 #(2 + 3 = 5), and so on. # #Below we've started a class called FibSeq. At any time, #FibSeq holds two values from the Fibonacci sequence: #back1 and back2. # #Create a new method inside FibSeq called next_number. The #next_number method should: # # - Calculate and return the next number in the sequence, # based on the previous 2. # - Update back2 with the former value of back1, and update # back1 with the new next item in the sequence. # #This means that consecutive calls to next_number should #yield each consecutive number from the Fibonacci sequence. #Calling next_number 5 times would print 1, 2, 3, 5, and 8.

class FibSeq: def __init__(self): self.back1 = 1 self.back2 = 0

#The code below will test your method. It's not used for #grading, so feel free to change it. As written, it should #print 1, 2, 3, 5, and 8. newFib = FibSeq() print(newFib.next_number()) print(newFib.next_number()) print(newFib.next_number()) print(newFib.next_number()) print(newFib.next_number())