先对矩阵的行进行操作，然后对矩阵的列进行操作会产生代码重复

Question

我有以下（Python）代码来检查是否有任何行或列包含相同的值：

    # Test rows ->  

        # Check each row for a win
        for i in range(self.height):                    # For each row ...

            firstValue = None                           # Initialize first value placeholder

            for j in range(self.width):                 # For each value in the row
                if (j == 0):                                # If it's the first value ...
                    firstValue = b[i][j]                        # Remember it
                else:                                       # Otherwise ...
                    if b[i][j] != firstValue:                   # If this is not the same as the first value ...
                        firstValue = None                           # Reset first value
                        break                                       # Stop checking this row, there's no win here

            if (firstValue != None):                    # If first value has been set
                                                            # First value placeholder now holds the winning player's code
                return firstValue                           # Return it

    # Test columns ->

        # Check each column for a win
        for i in range(self.width):                 # For each column ...

            firstValue = None                           # Initialize first value placeholder

            for j in range(self.height):                # For each value in the column
                if (j == 0):                                # If it's the first value ...
                    firstValue = b[j][i]                        # Remember it
                else:                                       # Otherwise ...
                    if b[j][i] != firstValue:                   # If this is not the same as the first value ...
                        firstValue = None                           # Reset first value
                        break                                       # Stop checking this column, there's no win here

            if (firstValue != None):                    # If first value has been set
                                                            # First value placeholder now holds the winning player's code
                return firstValue                           # Return it

显然，这里有很多代码重复。 如何重构此代码？

谢谢！

Answer 1

通常，当您想要重构时，请采用类似的代码片段并将它们放入函数中。因此，您可以使用一个函数来测试一个索引（行或列）相同的所有单元格，并使用另一个函数在所有列（或行）上调用该函数。尽管正如 Pär 在对您的问题的评论中指出的那样，如果您提供一些有关您尝试过的信息，那么帮助会更容易。

但是...另一个单独的（可能稍微相关的）问题是您的代码没有利用 Python 的函数功能。这很好，但正如您所知，像这样的任务，您必须检查数组（实际上是列表）的一堆不同元素，在以函数方式编写时通常更加更加简洁。例如，您的示例可以这样完成：

f = lambda x,y: x if x == y else False
# for Python <= 2.4 use this instead:
# f = lambda x,y: x == y and x or False
# test rows
[reduce(f,r) for r in array]
# test columns
reduce(lambda r,s: map(f,r,s), array)

尽管如果您试图了解代码的工作原理，那么这并没有多大帮助。

Answer 2

要检查一行中的所有元素是否相等，我建议构建该行的 python set，然后检查它是否只有一个元素。对于列也是如此。

例如这样

def testRowWin(b):
    for row in b:
        if len(set(row)) == 1:
            return True
    return False

def testColWin(b):
    return testRowWin(zip(*b))

Answer 3

def test_values(self, first, second, HeightWidth):
    for i in range(first):
        firstValue = None
        for j in range(second):
            (firstDimension, secondDimension) = (i, j) if HeightWidth else (j, i)
            if secondDimension == 0:
                firstValue = b[firstDimension][secondDimension]
            else:
                if b[firstDimension][secondDimension] != firstValue:
                    firstValue = None
                    break
    return firstValue

firstValue = test_values(self, self.height, self.width, true)
if firstValue:
    return firstValue

firstValue test_values(self, self.width, self.height, false)
if firstValue:
    return firstValue