Python Program to Print the Fibonacci sequence

In this program, you'll learn to print the Fibonacci sequence using while loop.

To understand this example, you should have the knowledge of following Python programming topics:

A Fibonacci sequence is the integer sequence of 0, 1, 1, 2, 3, 5, 8....

The first two terms are 0 and 1. All other terms are obtained by adding the preceding two terms. This means to say the nth term is the sum of (n-1)th and (n-2)th term.

Source Code

# Program to display the Fibonacci sequence up to n-th term where n is provided by the user

# change this value for a different result
nterms = 10

# uncomment to take input from the user
#nterms = int(input("How many terms? "))

# first two terms
n1 = 0
n2 = 1
count = 0

# check if the number of terms is valid
if nterms <= 0:
   print("Please enter a positive integer")
elif nterms == 1:
   print("Fibonacci sequence upto",nterms,":")
   print(n1)
else:
   print("Fibonacci sequence upto",nterms,":")
   while count < nterms:
       print(n1,end=' , ')
       nth = n1 + n2
       # update values
       n1 = n2
       n2 = nth
       count += 1

Output

Fibonacci sequence upto 10 :
0, 1, 1, 2, 3, 5, 8, 13, 21, 34,

Note: To test this program, change the value of nterms.

Here, we store the number of terms in nterms. We initialize the first term to 0 and the second term to 1.

If the number of terms is more than 2, we use a while loop to find the next term in the sequence by adding the preceding two terms. We then interchange the variables (update it) and continue on with the process.

You can also solve this problem using recursion: Python program to print the Fibonacci sequence using recursion.