有没有更干净的方法来使用二维数组? [英] Is there a cleaner way to use a 2 dimensional array?

问题描述

我正在尝试创建一个二维数组类，但遇到了问题.我能想到的最好方法是将索引的元组传递给 get/setitem，并将其解压缩到函数中.不幸的是，实现看起来非常混乱:

I'm trying to make a 2D array class, and ran into a problem. The best way I could figure out to do it was to pass get/setitem a tuple of the indices, and have it unpacked in the function. Unfortunately though, the implementation looks really messy:

class DDArray:
    data = [9,8,7,6,5,4,3,2,1,0]

    def __getitem__ (self, index):
        return (self.data [index [0]], self.data [index [1]])

    def __setitem__ (self, index, value):
        self.data [index [0]] = value
        self.data [index [1]] = value

test = DDArray ()

print (test [(1,2)])

test [(1, 2)] = 120

print (test [1, 2])

我试着让它接受更多参数:

I tried just having it accept more parameters:

class DDArray:
    data = [9,8,7,6,5,4,3,2,1,0]

    def __getitem__ (self, index1, index2):
        return (self.data [index1], self.data [index2])

    def __setitem__ (self, index1, index2, value):
        self.data [index1] = value
        self.data [index2] = value

test = DDArray ()

print (test [1, 2])

test [1, 2] = 120

print (test [1, 2])

但这会导致一个奇怪的类型错误，告诉我我没有传递足够的参数(我猜下标运算符中的任何内容都被视为 1 个参数，即使有逗号).

but that results in a weird type error telling me that I'm not passing enough arguments (I guess anything inside of the subscript operator is considered 1 argument, even if there's a comma).

(是的，我知道，上面的类实际上并不是一个二维数组.我想在开始实际制作二维数组之前先弄清楚运算符.)

(Yes, I know, the above class isn't actually a 2D array. I wanted to have the operators figured out before I moved on to actually making it 2D.)

有没有一种标准的方法看起来更干净一点?谢谢

Is there a standard way of doing it that looks a little cleaner? Thanks

推荐答案

有几种方法可以做到这一点.如果你想要像 test[1][2] 这样的语法，那么你可以让 __getitem__ 返回一个列(或行)，它可以用 __getitem__ 再次索引(甚至只是返回一个列表).

There are a couple ways you can do this. If you want syntax like test[1][2], then you can have __getitem__ returns a column (or row), which can be indexed again with __getitem__ (or even just return a list).

然而，如果你想要语法test[1,2]，你就走在正确的轨道上，test[1,2]实际上传递了元组(1,2) 到 __getitem__ 函数，因此您在调用它时不需要包含括号.

However, if you want the syntax test[1,2], you are on the right track, test[1,2] actually passes the tuple (1,2) to the __getitem__ function, so you don't need to include the parantheses when calling it.

您可以像这样使 __getitem__ 和 __setitem__ 实现不那么混乱:

You can make the __getitem__ and __setitem__ implementations a little less messy like so:

def __getitem__(self, indices):
    i, j = indices
    return (self.data[i], self.data[j])

当然是您对 __getitem__ 的实际实现.关键是您已将索引元组拆分为适当命名的变量.

with your actual implementation of __getitem__ of course. The point being that you have split the indices tuple into appropriately named variables.

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