附加到嵌套列表

Question

我正在使用嵌套列表在我创建的字典中查找值。然后我想将找到的值附加到列表中。我不知道如何编码的问题是如何将附加的值保留在同一个嵌套列表结构中？这是我将值附加到空列表的最后一行的代码。

#Creating a dictionary of FID: LU_Codes from external txt file
import sys, arcpy, string, csv

text_file = open("H:\SWAT\NC\FID_Whole.txt", "r")
Lines = text_file.readlines()
text_file.close()

FID_LU = map(string.split, Lines)
#print FID_LU
FID_GC_dict = dict(FID_LU)

Neighbors_file = open("H:\SWAT\NC\Sh_Neighbors2.txt","r")
Entries = Neighbors_file.readlines()
Neighbors_file.close()

Neighbors_List = map(string.split, Entries)

print Neighbors_List

#FID = [x[0] for x in Neighbors_List]
#print FID

gridList = []
for list in Neighbors_List:
    for item in list:
       #print FID_GC_dict[item]
       gridList.append(int(FID_GC_dict[item]))


 print gridList

这是邻居列表的输出（正确）：

[['0', '1', '11', '12', '13'], ['1', '0', '2', '12', '13', '14'], ['2', '1', '3', '13', '14', '15'], ['3', '2', '4', '14', '15', '16'], ['4', '3', '5', '15', '16', '17'], ['5', '4', '6', '16', '17', '18'], ['6', '5', '7', '17', '18', '19'], ['7', '6', '8', '18', '19', '20'], ['8', '7', '9', '19', '20', '21'], ['9', '8', '20', '21', '22'], ['10', '11']]

这是 gridList 的输出（不正确）：

[3, 3, 4, 4, 4, 3, 3, 3, 4, 4, 4, 3, 3, 3, 4, 4, 2, 3, 3, 3, 4, 2, 2, 3, 3, 3, 2, 2, 2, 3, 3, 3, 2, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4]

我希望 gridList 看起来像：

[[3, 3, 4, 4, 4], [3, 3, 3, 4, 4, 4], [3, 3, 3, 4, 4, 2], [3, 3, 3, 4, 2, 2], [3, 3, 3, 2, 2, 2], [3, 3, 3, 2, 2, 3], [3, 3, 3, 2, 3, 3], [3, 3, 3, 3, 3, 3], [3, 3, 3, 3, 3, 3], [3, 3, 3, 3, 3], [3, 4]]

任何帮助，将不胜感激。我是 python 的新手……阅读这些帖子有帮助，但我正在努力解决这个问题。

谢谢！

Answer 1

制作一个临时列表，row。将内循环中的项目附加到row，然后在外循环中将行附加到gridList：

gridList = []
for nlist in Neighbors_List:
    row = []
    for item in nlist:
       row.append(int(FID_GC_dict[item]))
    gridList.append(row)

请注意，您也可以在此处使用列表理解：

gridList = [[int(FID_GC_dict[item]) for item in nlist] 
            for nlist in Neighbors_List]

附注。最好不要命名变量list，因为它会掩盖同名的内置类型。