how to return the nth fibonacci in python

# Dynamic approach to get nth fibonacci number
arr = [0,1]

def fibonacci(n):
   if n<0:
      print("Fibbonacci can't be computed")
   elif n<=len(arr):
      return arr[n-1]
   else:
      temp = fibonacci(n-1)+fibonacci(n-2)
      arr.append(temp)
      return temp

print(fibonacci(9))

# Function for nth Fibonacci number 
  
def Fibonacci(n): 
    if n<0: 
        print("Incorrect input") 
    # First Fibonacci number is 0 
    elif n==1: 
        return 0
    # Second Fibonacci number is 1 
    elif n==2: 
        return 1
    else: 
        return Fibonacci(n-1)+Fibonacci(n-2) 
  
# Driver Program 
  
print(Fibonacci(9))