条件iloc语句。“时间序列分析”

Question

在Python中，我有一个包含多行和多列的数据集。如果一个column=X的值，我对它上面的行和右边的列的值感兴趣，所以加上值x的前一个位置的[1,1]。

解决这个问题的最好方法是什么？如果是cell =X，有没有一种动态的方法，我可以获得位置，然后添加X数量的行和列，“因为我对那个单元格的值感兴趣”？

Visual Example of Question

Answer 1

假设我们的数组定义为：

import numpy as np
arr = np.array([[9, 8, 4, 5, 2],
                [0, 3, 5, 6, 7],
                [6, 6, 2, 0, 6],
                [2, 0, 2, 5, 8],
                [2, 6, 9, 7, 9]])

一种直接的解决方案是循环遍历感兴趣的列。

colIndex = 2
X = 2
rDelta = -1 #row change, up is negative!
cDelta = 1 #col change, right is positive

numberRows = np.shape(arr)[1]
output = []

#This loops through all the values in the specified column and looks for 
#matches, if a match is found it is added to an output list
#Note that we only look at values that would result in valid output
#   for example we will not look at the first row if 
#   we would need to index into the row above for the output
for i in range(max(-rDelta,0),min(numberRows,numberRows-rDelta)):
    if(arr[i,colIndex]==X):
        #replace this with your processing
        output.append(arr[i+rDelta,colIndex+cDelta]) 

运行这段代码后，我得到的输出如下

[6, 0]

它们是第二列中2的上边和右边的值。