How explain why Python is easier/nicer than Lisp which has a simpler grammar/syntax?

[Richard Damon]

On 8/7/20 4:08 PM, Terry Reedy wrote:
> On 8/7/2020 11:46 AM, Chris Angelico wrote:
>
>> My point is that doing Fibonacci recursively is arguably more elegant
>> while being materially worse at performance.
>
> This is a common misconception.  Linear iteration and tail recursion
> are equivalent.  The issue is calculating values once versus multiple
> times.  Here is the fast recursion equivalent to the fast iteration.
>
> def fib(n, pair=(1,0)):
>    previous, current = pair
>    if n:
>       return fib(n-1, (current, previous + current))
>    else:
>       return current
>
> for i in range(10): print(fib(i), end=' ')
> # 0 1 1 2 3 5 8 13 21 34
>
> One can also do the slow algorithm, with wasteful duplication,
> iteratively with one or two stacks of values instead of the hidden
> stack of execution frames.  I don't remember the details right now
> without checking a text.
>
But your example breaks the 'problem' in the recursion that Fibonacci,
when expressed 'naturally', the current value is based on two different
earlier values. You have morphed the definition, using basically the
iterative solution, so that the recursive call to fir(0, ...) doesn't
actually calculate the fib(0) value, but fib(n).

Yes, this shows that you can convert an iterative solution into a
recursive solution with a bit of hand waving, but you still end up with
a program based on the iterative algorithm, not the possibly natural
recursive one.

-- 
Richard Damon