COVID-19 Quarantine House: Hollywood Walk of Fame Edition

$ python quarantine-house.py  40.7484 -73.9856
Humphrey Bogart
Patrick Swayze
Ozzy Osbourne
Kathy Bates
Earth, Wind and Fire

import sys
import math

# Settings: the resolution is 10^(-ires) and we use m words.
ires = 10000
ndp = int(math.log10(ires))
m = 5

# Read the word list
words = [line.strip() for line in open('hollywood-list.txt')]

# Total number of locations
N = 180 * 360 * ires**2
# "Length" of each of the m dimensions
d = round(N**(1/m))
if d > len(words):
    print(f'Warning: I need {d} words, but got {len(words)}.')
    sys.exit(1)


def encode(lat, lng):
    """Encode a latitude and longitude as m words."""

    # Integer, scaled longitude and latitude as positive quantities.
    ilam, iphi = int((lat+90)*ires), int((lng+180)*ires)
    # The one-dimensional index corresponding to ilam, iphi.
    idx = 180 * ires * iphi + ilam

    # Construct the word sequence.
    j = [0]*m
    for i in range(m):
        idx, j[i] = divmod(idx, d)

    return '\n'.join(words[j[i]] for i in range(m))

def decode(code):
    """Decode three words in the list code as a latitude and longitude."""

    j = [words.index(word) for word in code]
    # Get the one-dimensional index corresponding to the code.
    idx = 0
    for i in range(m):
        idx += d**i * j[i]
    # Convert to longitude and latitude, accounting for the offset.
    iphi, ilam = divmod(idx, 180 * ires)
    lam, phi = ilam / ires - 90, iphi / ires - 180
    return round(lam, ndp), round(phi, ndp)

try:
    lat, lng = float(sys.argv[1]), float(sys.argv[2])
    print(encode(lat, lng))
except (IndexError, ValueError):
    if len(sys.argv) == m+1:
        code = sys.argv[1:]
    else:
        code = sys.argv[1].split('\n')
    print(decode(code))