maze.py

#maze

#recursive function
def searchFrom(maze, startRow, startColumn):
    maze.updatePosition(startRow, startColumn)

    #Check for base cases:

    #1. We have run into an obstacle, return False
    if maze[startRow][startColumn] == OBSTACLE:
        return False

    #2. We have found a square that has already been explored
    if maze[startRow][startColumn] == TRIED:
        return False

    #3. Success, an outside edge not occupied by an obstacle
    if maze.isExit(startRow, startColumn):
        maze.updatePosition(startRow, startColumn, PART_OF_PATH)
        return True
    maze.updatePosition(startRow,startColumn,TRIED)

    #Otherwise, use logical short circuiting to try each
    #direction in turn (if needed)
    found = searchFrom(maze, startRow-1, startColumn) or \
            searchFrom(maze, startRow+1, startColumn) or \
            searchFrom(maze, startRow, startColumn-1) or \
            searchFrom(maze, startRow, startColumn+1)

    if found:
        maze.updatePosition(startRow, startColumn, PART_OF_PATH)
    else:
        maze.updatePosition(startRow, startColumn, DEAD_END)

    return found

#define Maze class
class Maze:
    def __init__(self, mazeFileName):
        rowsInMaze = 0
        columnsInMaze = 0
        self.mazelist = []
        mazeFile = open(mazeFileName, 'r')
        rowsInMaze = 0 #Is it redundant?
        for line in mazeFile:
            rowList = []
            col = 0
            for ch in line[:-1]:
                rowList.append(ch)
                if cd == 'S':
                    self.startRow = rowsInMaze
                    self.startCol = col
                col = col + 1
            rowsInMaze = rowsInMaze + 1
            self.mazelist.append(rowList)
            columnsInMaze = len(rowList)

        self.rowsInMaze = rowsInMaze
        self.columnsInMaze = columnsInMaze

        #set up the screen
        self.xTranslate = -columnsInMaze/2 #???
        self.yTranslate = rowsInMaze/2
        self.t = Turtle(shape='turtle')
        setup(width=600,height=600)
        #set the coordinates of the screen
        setworldcoordinates(-(columnsInMaze-1)/2-.5,
                            -(rowsInMaze-1)/2-.5,
                            (columnsInMaze-1)/2+.5,
                            (rowsInMaze-1)/2+.5)

    def drawMaze(self):
        for y in range(self.rowsInMaze):
            for x in range(self.columnsInMaze):
                if self.mazelist[y][x] == OBSTACLE:
                    self.drawCenteredBox(x+self.xTranslate,
                                         -y+self.yTranslate,
                                         'tan')
        self.t.color('black','blue')

    def drawCenteredBox(self,x,y,color):
        tracer(0)
        self.t.up()
        self.t.goto(x-.5,y-.5)
        self.t.color('black',color)
        self.t.setheading(90)
        self.t.down()
        self.t.begin_fill()
        for i in range(4):
            self.t.forward(1)
            self.t.right(90)
        self.t.end_fill()
        update()
        tracer(1)

    def moveTurtle(self,x,y):
        self.t.up()
        self.t.setheading(self.t.towards(x+self.xTranslate,
                                         -y+self.yTranslate))
        self.t.goto(x+self.xTranslate,-y+self.yTranslate)

    def dropBreadcrumb(self,color):
        self.t.dot(color)

    def updatePosition(self,row,col,val=None):
        if val:
            self.mazelist[row][col] = val
        self.moveTurtle(col,row)

        if val == PART_OF_PATH:
            color = 'green'
        elif val == OBSTACLE:
            color = 'red'
        elif val == TRIED:
            color = 'black'
        elif val == DEAD_END:
            color = 'red'
        else:
            color = None

        if color:
            self.dropBreadcrumb(color)

    def isExit(self,row,col):
         return (row == 0 or
                 row == self.rowsInMaze-1 or
                 col == 0 or
                 col == self.columnsInMaze-1 )

    def __getitem__(self,idx):
         return self.mazelist[idx]