When a function calls itself, we say that the function is a recursive function. Let's look at the example of the Fibonacci series. It is defined as follows: f(1) is equal to 1, f(2) is equal to 1, and for n greater than 2, f(n) is equal to f(n-1) + f(n-2). Let's look at the implementation of this function in code, as follows:
...def fibonacci(n): if n <= 2: return 1 else: return fibonacci(n-1) + fibonacci(n-2)print "fibonacci(5)", fibonacci(5)...
In the preceding code, we have created our function, fibonacci, which takes a number, n, as input. If n is less than or equal to 2, it returns 1; otherwise, it returns fibonacci(n-1) + fibonacci(n-2). Toward the end of the code, we have calculated the value of fibonacci(5), which is ...