fibonacci.py

#Fibonacci series
    
def fibonacci( number ) :
    sum_n2 = 1; #F(1)
    sum_n1 = 1; #F(2)
    for i in range( number ) :
        sum_n = sum_n1 + sum_n2
        sum_n1 = sum_n
        sum_n2 = sum_n1
    return sum_n