""" Fibonacci Module """
def fib(n):
""" Calculates the n-th Fibonacci number iteratively """
a, b = 0, 1
for i in range(n):
a, b = b, a + b
return a
if __name__ == "__main__":
if fib(0) == 0 and fib(10) == 55 and fib(50) == 12586269025:
print("Test for the fib function was successful!")
else:
print("The fib function is returning wrong values!")