Fibonacci Sequence 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)

# method 2: use `for` loop
def fib2(num):
	a, b = 1, 1
	for _ in range(num - 1):
		a, b = b, a + b
	return a


print(fib(6))  # 8
print(fib2(6))  # same result, but much faster

Example 2: fibonacci sequence python

num = 1
num1 = 0
num2 = 1
import time
for i in range(0, 10):
    print(num)
    num = num1 + num2
    num1 = num2
    num2 = num
    time.sleep(1)

Example 3: fibonacci

# Easy fibonacci exercise
# Method #1
def fibonacci(n):
    # 1th: 0
    # 2th: 1
    # 3th: 1 ...
    if n == 1:
        return 0
    elif n == 2:
        return 1
    else:
        return fibonacci(n - 1) + fibonacci(n - 2)

# Method #2
def fibonacci2(n):
    if n == 0: return 0
    n1 = 1
    n2 = 1
    # (1, n - 2) because start by 1, 2, 3... not 0, 1, 1, 2, 3....
    for i in range(1, n - 2):
        n1 += n2
        n2 = n1 - n2
    return n1


print(fibonacci(13))
# return the nth element in the fibonacci sequence

Example 4: fibonacci sequence

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...

Example 5: fibonacci sequence

def fibonacci(n):
    if n <= 0:
        return 0
    elif n == 1:
        return 1
    else:
        return fibonacci(n-1) + fibonacci(n-2)

Example 6: fibonacii sequence code

# 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