python - 在Python3中分析和计算列表列表中的新值

Question

好吧，我会尽力正确地解释自己:

我正在使用 python3，并在结构中使用列表列表:

[[position, color, counts],...]

结果首先按颜色排序，然后按位置排序。

如果计数和位置的平均值具有相同的颜色并且它们之间的位置最多为 +-2，我需要将它们合并起来。

输入的简短测试示例是:

[ [1, "red", 3],  [2, "red", 2],  [3, "red", 3], [5, "red", 1], [3, "green", 9],  [10, "green", 4] ]

预期的输出:

[ [2.75, "red", 9], [3, "green", 9], [10, "green", 4]

我对像 5“红色”1 这样的情况特别有问题，因为如果我执行平均值，则距离可能会增加，从而导致迭代失败，但我想考虑它，因为它位于 5 个“红色”1 的 2 个位置上一篇...

有办法解决吗？

提前致谢!

Answer 1

我想我已经解决了你的问题。此代码片段应该可以工作，但可能可以优化:

colors = [ [1, "red", 3], [2, "red", 2], [3, "red", 3], [5, "red", 1], [3, "green", 9], [10, "green", 4] ]

def avg(list): 
    return sum(list) / float(len(list))

def process(colors, threshold=2): 
    colors_combined = {}
    colors_processed = []

    # sort colors by their name
    for color in colors: 
        position, color_name, count = color

        if color_name not in colors_combined.keys(): 
            colors_combined[color_name] = []

        colors_combined[color_name].append([position, count])

    # print colors_combined

    # process the data
    for color in colors_combined.keys(): 
        data = colors_combined[color]

        if len(data) == 1: # there can't be a case, where len(data) = 0
            colors_processed.append([data[0], color, data[1]])
        else: # more than 1 positions to check
            last_position = data[0][0]
            positions = [last_position]
            count_combined = data[0][1]

            for element in data[1:]: 
                if abs(last_position - element[0]) <= threshold: # element is inside of the distance
                    positions.append(element[0])
                    count_combined += element[1]
                else: 
                    colors_processed.append([avg(positions), color, count_combined])
                    positions = [element[0]]
                    count_combined = element[1]

                last_position = element[0]

            if len(positions) > 0: # the last processed elements where inside the distance, but not added
                colors_processed.append([avg(positions), color, count_combined])

    return colors_processed

print process(colors)

输出如下所示:

[[3.0, 'green', 9], [10.0, 'green', 4], [2.75, 'red', 9]]

如果您需要排序结果，可以添加颜色排序而不是 colors_combined.keys()。