Aoc 2016 Day 2 with Python

day2.py

#!/usr/bin/env python3

import sys
import numpy as np

KEYPADS = [
    np.array([
        ["1", "2", "3"],
        ["4", "5", "6"],
        ["7", "8", "9"],
    ]),
    np.array([
        [" ", " ", "1", " ", " "],
        [" ", "2", "3", "4", " "],
        ["5", "6", "7", "8", "9"],
        [" ", "A", "B", "C", " "],
        [" ", " ", "D", " ", " "],
    ])
]

DIRECTIONS = {
    "L": ( 0, -1),
    "R": ( 0,  1),
    "U": (-1,  0),
    "D": ( 1,  0),
}

lines = sys.stdin.readlines()

for keypad in KEYPADS:
    result = ""
    position = next(zip(*np.where(keypad == "5")))

    for line in lines:
        for char in line.strip():
            newPosition = tuple(np.add(position, DIRECTIONS[char]))

            if newPosition in zip(*np.where(keypad)):
                position = newPosition

        result += keypad[position]

    print(result)