fibonacci series in python3 code example

Example 1: fibonacci sequence python

# WARNING: this program assumes the
# fibonacci sequence starts at 1
def fib(num):
  """return the number at index num in the fibonacci sequence"""
  if num <= 2:
    return 1
  return fib(num - 1) + fib(num - 2)


print(fib(6))  # 8

Example 2: fibonacci series in python

# 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")
elif nterms == 1:
   print("Fibonacci sequence upto",nterms,":")
   print(n1)
else:
   print("Fibonacci sequence:")
   while count < nterms:
       print(n1)
       nth = n1 + n2
       # update values
       n1 = n2
       n2 = nth
       count += 1