fibonacci.py

"""
This is a pure Python implementation of Dynamic Programming solution to the fibonacci
sequence problem.
"""


class Fibonacci:
    def __init__(self, N=None):
        self.fib_array = []
        if N:
            N = int(N)
            self.fib_array.append(0)
            self.fib_array.append(1)
            for i in range(2, N + 1):
                self.fib_array.append(self.fib_array[i - 1] + self.fib_array[i - 2])
        elif N == 0:
            self.fib_array.append(0)
        print(self.fib_array)

    def get(self, sequence_no=None):
        """
        >>> Fibonacci(5).get(3)
        [0, 1, 1, 2, 3, 5]
        [0, 1, 1, 2]
        >>> Fibonacci(5).get(6)
        [0, 1, 1, 2, 3, 5]
        Out of bound.
        >>> Fibonacci(5).get(-1)
        [0, 1, 1, 2, 3, 5]
        []
        """
        if sequence_no is not None:
            if sequence_no < len(self.fib_array):
                return print(self.fib_array[: sequence_no + 1])
            else:
                print("Out of bound.")
        else:
            print("Please specify a value")


if __name__ == "__main__":
    print("\n********* Fibonacci Series Using Dynamic Programming ************\n")
    print("\n Enter the upper limit for the fibonacci sequence: ", end="")
    try:
        N = int(input().strip())
        fib = Fibonacci(N)
        print(
            "\n********* Enter different values to get the corresponding fibonacci "
            "sequence, enter any negative number to exit. ************\n"
        )
        while True:
            try:
                i = int(input("Enter value: ").strip())
                if i < 0:
                    print("\n********* Good Bye!! ************\n")
                    break
                fib.get(i)
            except NameError:
                print("\nInvalid input, please try again.")
    except NameError:
        print("\n********* Invalid input, good bye!! ************\n")

    import doctest

    doctest.testmod()