打破多个循环python特定的问题

时间:2011-05-19 00:06:26

标签: python loops break

我的问题是关于第二次突破声明: 如果x == xstart和y == ystart:                     破

所以这个break语句突破了while true循环的正确性?但是它会回到下一个最接近的循环(即while board [x] [y] = OtherTile :)但是由于这个条件不满足,它会回到原来的xdirection,ydirection循环?我只是想看看我的理解是否正确。

if board[xstart][ystart] not OnBoard(xstart, ystart) or board[xstart][ystart] != ' ':
    return False

#temporarily set the tile on the board, but change it back to a blank before the end of this function
board[xstart][ystart] = tile

#Set computer tile
if tile == 'X':
    OtherTile = 'O'
else:
    OtherTile = 'X'

#empty list of tiles to flip
TilesToFlip = []

#this is a for loop for two variables.  Each list of two represents a position away from the orignal spot
for xdirection, ydirection in [[1,0], [0,1], [-1,0], [0,-1], [1,-1], [1,1], [-1,1], [-1,-1]]:

    #we set x and y to the original coordinates passed to us because we want to preserve the orignal values
    x, y = xstart, ystart
    x = x + xdirection
    y = y + ydirection

    #after the first iteration, check to see if the adjacent piece is on the board and if it's the OtherTile:
    if isOnBoard(x,y) and board[x][y] == OtherTile:
        x = x + xdirection
        y = y + ydirection
        #if the next piece is not on the board, go back to the for loop to test another direction
        if not isOnBoard(x,y):
            continue
        while board[x][y] = OtherTile:
            x = x + xdirection
            y = y + ydirection
            #we break here because if we had just continued it would have gone back to the while loop.
            #since we're breaking, it goes back to the original for loop (if it goes off the board)
            if not isOnBoard(x,y):
                break

        #it finishes with the while loop if it reaches a tile that is not the OtherTile (i.e. it's blank or it's the player's)
        #so we check to see if it's the player's
        if board[x][y] == tile:
            #if it is the player's tile, then we go in the reverse direction, appending each tile to the TilesToFlip list
            while True:
                x = x - xdirection
                y = y - ydirection
                #when we reach the original tiles, we break (by then we have all the tiles that need to be flipped in store in the new list)
                if x == xstart and y == ystart:
                    break
                TilesToFlip.append([x,y])

1 个答案:

答案 0 :(得分:2)

它只会打破while循环。循环将一直持续到x == xstart和y == ystart。

一旦满足该条件,它将继续在外部for循环中。