Fibonacci Function

fib.py

"""
Implementation of a function that returns elements from the Fibonacci sequence using DP

https://en.wikipedia.org/wiki/Fibonacci_number
https://en.wikipedia.org/wiki/Dynamic_programming
"""
import logging


logger = logging.getLogger(__name__)
logger.setLevel(logging.INFO)
sh = logging.StreamHandler()
sh.setLevel(logging.INFO)
logger.addHandler(sh)


# Our cache for DP
memory = {
    0: 0,
    1: 1
}


def fib(n):
    """
    Calculate the nth Fibonacci number.
    
    Memoizes fibonacci numbers for later reuse.
    """
    logger.info(f"Calculating fib({n})")
    try:
        logger.info(f"Looking up fib({n}) in memory...")
        memory[n]
        logger.info(f"Found fib({n}) in cache!")
    except KeyError:
        logger.info(f"fib({n}) has not yet been memoized. Caching the result now.")
        memory[n] = fib(n-1) + fib(n-2)
    logger.info(f"Returning fib({n})")
    return memory[n]


if __name__ == "__main__":
    for i in range(11):
        print(f"fib({i}) = {fib(i)}")

Wrote this while demoing coderpad.io - very happy with the platform so far!