Python返回None而不是True / False

时间:2015-08-11 17:22:11

标签: python python-3.x

我正在创建一个简单的程序,它会在网格区域中找到一个单词库,坐标和网格。当我在底部使用print语句时,python返回“None”而不是接收True或False。我的代码可以在下面看到,任何改进都值得赞赏。谢谢你:

def grid_string_maker(word_block, x, y): # creates string from grid
    pos_word_vert = ""
    pos_word_hor = ""
    if y == 0:
        pos_word_vert += word_block[y][x]
        pos_word_vert += word_block[y+1][x]
        pos_word_vert += word_block[y+2][x]
        return pos_word_vert
    elif y == 1:
        pos_word_vert += word_block[y-1][x]
        pos_word_vert += word_block[y][x]
        pos_word_vert += word_block[y+1][x]
        return pos_word_vert
    elif y == 2:
        pos_word_vert += word_block[y-2][x]
        pos_word_vert += word_block[y-1][x]
        pos_word_vert += word_block[y][x]
        return pos_word_vert
    if x == 0:
        pos_word_hor += word_block[y][x]
        pos_word_hor += word_block[y][x+1]
        pos_word_hor += word_block[y][x+2]
        return pos_word_hor
    elif x == 1:
        pos_word_hor += word_block[y][x-1]
        pos_word_hor += word_block[y][x]
        pos_word_hor += word_block[y][x+1]
        return pos_word_hor
    elif x == 2:
        pos_word_hor += word_block[y][x-2]
        pos_word_hor += word_block[y][x-1]
        pos_word_hor += word_block[y][x]
        return pos_word_hor

def find_word(word_block, x, y, validate_words):
    pos_word_vert = grid_string_maker(word_block, x, y)
    pos_word_hor = grid_string_maker(word_block, x, y)
    if pos_word_vert == validate_words: #Checks if the string vertically from up to down matches
        return True
    elif pos_word_vert != validate_words: #If top to bottom doesnt match, it reverses
        rev_pos_word_vert = pos_word_vert[::-1]
    if rev_pos_word_vert == validate_words: #Checks if the reversed bottom to top matches
        return True
    if pos_word_hor == validate_words: #Checks if the string vertically from up to down matches
        return True
    elif pos_word_hor != validate_words: #If top to bottom doesnt match, it reverses
        rev_pos_word_hor = pos_word_hor[::-1]
    if rev_pos_word_hor == validate_words: #Checks if the reversed bottom to top matches
        return True
    else:
        return False

validate_words = set("THE")

word_block = [
    ["A","A","A"],
    ["T","H","E"],
    ["A","A","A"]
]

print find_word(word_block, 2, 1, validate_words)

2 个答案:

答案 0 :(得分:4)

我可以发现您的代码中存在许多问题 -

  1. 在您的函数grid_string_maker(word_block, x, y)中,您始终返回pos_word_vert,您永远不会返回水平的0,1,2。这是因为每次调用该函数时,它都从启动开始,而不是从中断的位置开始。此外,您不需要这么多ifs,您可以直接使用y-1作为索引而不是y == 1 y,因为您已经知道y-1是否为1,{ {1}}为0,等等。您应该更改函数以将顶点和水平字符串一起作为元组返回,然后将它们接受为单独的字符串。

  2. 在您的函数中 - find_word() - 在您的第二个if..elif..else中,永远不会达到else,因为您检查两件事是否相等,以及您的elif检查如果他们不平等,就没有第三种选择。除此之外,如果在此之前它没有返回true,则应该从函数返回False作为默认值。

  3. 此外,不是按照设置创建validate_words,而是将其创建为字符串。将set用于此变量没有任何好处。

  4. 代码 -

    def grid_string_maker(word_block, x, y): # creates string from grid
        pos_word_vert = word_block[0][x] + word_block[1][x] + word_block[2][x]
        pos_word_hor = word_block[y][0] + word_block[y][1] + word_block[y][2]
        return (pos_word_vert, pos_word_hor)
    
    def find_word(word_block, x, y, validate_words):
        pos_word_vert, pos_word_hor = grid_string_maker(word_block, x, y)
        if pos_word_vert == validate_words: #Checks if the string vertically from up to down matches
            return True
        else: #If top to bottom doesnt match, it reverses
            rev_pos_word_vert = pos_word_vert[::-1]
            if rev_pos_word_vert == validate_words: #Checks if the reversed bottom to top matches
                return True
        if pos_word_hor == validate_words: #Checks if the string vertically from up to down matches
            return True
        else: #If top to bottom doesnt match, it reverses
            rev_pos_word_hor = pos_word_hor[::-1]
            if rev_pos_word_hor == validate_words: #Checks if the reversed bottom to top matches
                return True
        return False
    
    validate_words = "THE"
    

答案 1 :(得分:2)

第47行是当前word_block值的问题:

elif pos_word_hor != validate_words: #If top to bottom doesnt match, it reverses
   rev_pos_word_hor = pos_word_hor[::-1]
   if rev_pos_word_hor == validate_words: #Checks if the reversed bottom to top matches
      return True

问题是else if返回true所以它进入该语句但if里面的if是false,所以它只是退出而不返回任何东西。最后的ELSE捕获跳过(因为它在ELSE IF之后什么都不做)并且最终没有返回。如果您在第47行和第8行显示问题并显示问题(并返回True)。