battleship score [interview question]

battleship_score.py

import pprint
import string

from typing import Tuple

def lookup_str_index(char: str):
    return string.ascii_uppercase.index(char) + 1

def parse_coord(locstr: str) -> Tuple[int, int]:
    return (int(locstr[0]), lookup_str_index(locstr[1]))

class Ship:

    def __init__(self, locstr: str) -> 'Ship':
        topleft, _, bottomright = locstr.partition(" ")
        self.topleft = parse_coord(topleft)
        self.bottomright = parse_coord(bottomright)
        self.area = abs(self.bottomright[1] - self.topleft[1] + 1) \
            * abs(self.bottomright[0] - self.topleft[0] + 1)
        self.hitcounter = 0

    def fire_at(self, coord: Tuple[int, int]) -> bool:
        if self.topleft[0] <= coord[0] <= self.bottomright[0] and \
                self.topleft[1] <= coord[1] <= self.bottomright[1]:
            self.hitcounter += 1
            return True
        return False

    def __str__(self) -> str:
        return "({}, {}), area: {}, hits: {}".format(self.topleft, self.bottomright, self.area, self.hitcounter)

    __repr__ = __str__

if __name__ == "__main__":

    # return the number of ships that have been sunk, and the number of hits
    # on non-sunken ships

    gridSize = 4
    ships = "1B 2C,2D 4D"
    shipsHit = "2B 2D 3D 4D 4A"
    # create ships
    allShips = []
    for ship in ships.split(","):
        allShips.append(Ship(ship))
    shots = []
    # create artillery
    for shot in shipsHit.split(" "):
        shots.append(parse_coord(shot))
    # fire each shot at every ship
    for s in shots:
        for sh in allShips:
            sh.fire_at(s)
    # calculate result
    sunken_ships = 0
    hits = 0
    for s in allShips:
        if s.area <= s.hitcounter:
            sunken_ships += 1
        else:
            hits += s.hitcounter
    # print result
    print("{}, {}".format(sunken_ships, hits))