checkFibonacciNum.py

# python program to check if x is a perfect square
import math
 
# A utility function that returns true if x is perfect square
 
 
def isPerfectSquare(x):
    s = int(math.sqrt(x))
    return s*s == x
 
# Returns true if n is a Fibonacci Number, else false
 
 
def isFibonacci(n):
 
    # n is Fibonacci if one of 5*n*n + 4 or 5*n*n - 4 or both
    # is a perfect square
    return isPerfectSquare(5*n*n + 4) or isPerfectSquare(5*n*n - 4)
 
 
# A utility function to test above functions
for i in range(1, 11):
    if (isFibonacci(i) == True):
        print(i, "is a Fibonacci Number")
    else:
        print(i, "is a not Fibonacci Number ")