Added fibonacci [python]

fibonacci_number/FibonacciNumber.py

@@ -1,20 +1,52 @@
-def fib(n):
-    if(n <= 1):
+def recursive_fibonacci(n):
+    """
+    Calculate the nth Fibonacci number using a recursive approach.
+
+    :param n: The index of the Fibonacci number to calculate.
+    :return: The nth Fibonacci number.
+    """
+    if n <= 1:
         return n
     else:
-        return fib(n-1) + fib(n-2)
+        return recursive_fibonacci(n - 1) + recursive_fibonacci(n - 2)
+
+def iterative_fibonacci(n):
+    """
+    Calculate the nth Fibonacci number using an iterative approach.
+
+    :param n: The index of the Fibonacci number to calculate.
+    :return: The nth Fibonacci number.
+    """
+    previous_1 = 0
+    previous_2 = 1
+
+    for i in range(n):
+        current = previous_1 + previous_2
+        previous_1 = previous_2
+        previous_2 = current
+
+    return previous_1
 
 def main():
-    print("Enter the number :")
-    t = int(input())
-    if(t == 0):
-        print("Enter correct number!")
+    """
+    Main function to take user input and display the Fibonacci number.
+    """
+    print("Choose a Fibonacci calculation method:")
+    print("1. Recursive")
+    print("2. Iterative")
+
+    choice = int(input("Enter your choice (1 or 2): "))
+    n = int(input("Enter the index of the Fibonacci number: "))
+
+    if n <= 0:
+        print("Please enter a valid index greater than zero.")
     else:
-
-        for i in range(t):
-            x = fib(i)
-        print("fibonacci number is :")
-        print(x)
+        if choice == 1:
+            print("Fibonacci number at index", n, "is:", recursive_fibonacci(n))
+        elif choice == 2:
+            print("Fibonacci number at index", n, "is:", iterative_fibonacci(n))
+        else:
+            print("Invalid choice. Please select 1 or 2.")
 
 if __name__ == '__main__':
     main()