python - How to print statement after return in function?

Question

Here is the code as I currently have it:

def F(n):
    t=time.time()
    if n==0:
        return (0)
    elif n==1:
        return (1)
    else:
        return (F(n-1)+F(n-2))
    t1==time.time()
    return t
    F_time==t1-t
    print ('It took',F_time,'seconds to sort',n,'values using recursion')

I'm trying to print n numbers of the Fibonacci sequence and take the time before and after, but because of the return statements, it won't accept the variable after the return, nor the following print statement.

Answer 1

Anything after a return statement will never be executed. A return statement instantly terminates the function and "returns" to the caller. So it's really not possible.

There are two ways to get (nearly) the same result though.

Method #1:

The time it takes to execute a return statement is almost negligable. Therefore you can move the necessary benchmark code above the return and get an almost identical result as if it actually executed after a 'return' statement.

def F(n):
    t=time.time()
    if n==0:
        return (0)
    elif n==1:
        return (1)
    else:
        return (F(n-1)+F(n-2))
    t1==time.time()
    F_time==t1-t
    print ('It took',F_time,'seconds to sort',n,'values using recursion')
    return t

Method #2:

Put your timing code outside the function, this is the preferred method.

def F(n):

    if n==0:
        return (0)
    elif n==1:
        return (1)
    else:
        return (F(n-1)+F(n-2))
    return t

t=time.time()
F(5)
t1==time.time()
F_time==t1-t
print ('It took',F_time,'seconds to sort',5,'values using recursion')

Hope this helped, good luck!