How to write the Fibonacci Sequence?

Question

I had originally coded the program wrongly. Instead of returning the Fibonacci numbers between a range (ie. startNumber 1, endNumber 20 should = only those numbers between 1

Answer 1

If you're a fan of recursion you can cache the results easily with the lru_cache decorator (Least-recently-used cache decorator)

from functools import lru_cache


@lru_cache()
def fib(n):
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return fib(n-1) + fib(n-2)

If you need to cache more than 128 values you can pass maxsize as an argument to the lru_cache (e.g. lru_cache(maxsize=500). If you set maxsize=None the cache can grow without bound.