fibonacci series python recursion

1# By recursion
2def fib(n):
3    if n == 1 or n == 2:
4        return 1 
5    else:
6        return(fib(n-1) + fib(n-2))
7        
8n = 6
9for i in range(1,n+1):
10    print(fib(i))

1def Fibonacci( pos ):
2        #check for the terminating condition
3        if pos <= 1 :
4                #Return the value for position 1, here it is 0
5                return 0
6        if pos == 2:
7                #return the value for position 2, here it is 1
8                return 1
9 
10        #perform some operation with the arguments
11        #Calculate the (n-1)th number by calling the function itself
12        n_1 = Fibonacci( pos-1 )
13 
14        #calculation  the (n-2)th number by calling the function itself again
15        n_2 = Fibonacci( pos-2 )
16 
17        #calculate the fibo number
18        n = n_1 + n_2
19 
20        #return the fibo number
21        return n
22 
23#Here we asking the function to calculate 5th Fibonacci
24nth_fibo = Fibonacci( 5 ) 
25 
26print (nth_fibo)

1# Python program to display the Fibonacci sequence
2
3def recur_fibo(n):
4   if n <= 1:
5       return n
6   else:
7       return(recur_fibo(n-1) + recur_fibo(n-2))
8
9nterms = 10
10
11# check if the number of terms is valid
12if nterms <= 0:
13   print("Plese enter a positive integer")
14else:
15   print("Fibonacci sequence:")
16   for i in range(nterms):
17       print(recur_fibo(i))
18

1# WARNING: this program assumes the
2# fibonacci sequence starts at 1
3def fib(num):
4  """return the number at index num in the fibonacci sequence"""
5  if num <= 2:
6    return 1
7  return fib(num - 1) + fib(num - 2)
8
9
10print(fib(6))  # 8

1#fibonacci sequence with memory to increase the speed.
2class recur_fibo:
3    memory = {0: 1, 1:1}
4    
5    def fibonacci(n):
6        if n in recur_fibo.memory:
7            return recur_fibo.memory[n]
8        else:
9            recur_fibo.memory[n] = recur_fibo.fibonacci(n-1) + recur_fibo.fibonacci(n-2)
10            return recur_fibo.memory[n]
11
12if __name__ == "__main__":
13    value = recur_fibo.fibonacci(200)
14    print(value)