In this program, you’ll learn to print the Fibonacci sequence using while loop.
To understand this example, you should have the knowledge of the 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
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 | # Program to display the Fibonacci sequence up to n-th term nterms = int ( input ( "How many terms? " )) # first two terms n1, n2 = 0 , 1 count = 0 # check if the number of terms is valid if nterms < = 0 : print ( "Please enter a positive integer" ) # if there is only one term, return n1 elif nterms = = 1 : print ( "Fibonacci sequence upto" ,nterms, ":" ) print (n1) # generate fibonacci sequence else : print ( "Fibonacci sequence:" ) while count < nterms: print (n1) nth = n1 + n2 # update values n1 = n2 n2 = nth count + = 1 |
Output
1 2 3 4 5 6 7 8 9 | How many terms? 7 Fibonacci sequence: 0 1 1 2 3 5 8 |
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.