A* 算法的 Python 实现

本文使用 Python 语言实现 A* 算法。
算法流程和原理不赘述。

代码文件结构：

point.py

import sys


class Point(object):
    def __init__(self, x: int, y: int):
        self.x = x
        self.y = y

        self.cost = sys.maxsize

        self.parent = None

map.py

from typing import Tuple, List

from point import Point


class Map(object):
    def __init__(self, width: int, height: int, obstacles: List[Tuple[int, int]] = []):
        self.width = width
        self.height = height

        self.obstacles = [Point(x=osc[0], y=osc[1]) for osc in obstacles]

    def is_obstacle(self, i: int, j: int):
        for p in self.obstacles:
            if i==p.x and j==p.y:
                return True
            
        return False

a_star.py
有可视化的代码，最终生成视频，生成后可将中间生成的图片删除。

import os
import sys
import time
from typing import Tuple, List

from matplotlib.patches import Rectangle
import cv2
import glob

from point import Point
from map import Map


class AStar(object):
    """
    A* algorithm
    """
    def __init__(self, map: Map, origin: Tuple[int, int], target: Tuple[int, int]):
        """
        initialise
        
        :param map:  map
        :param origin:  starting point coordinates
        :param target:  ending point coordinates
        """

        self.map = map

        self.origin = Point(x=origin[0], y=origin[1])
        self.target = Point(x=target[0], y=target[1])

        self.open_points = []
        self.close_points = []

    def _basic_cost(self, point: Point):
        """
        basic cost from origin
        """
        return abs(point.x - self.origin.x) + abs(point.y - self.origin