Question

所以我有一个包含4个正方形坐标的JSON文件。 JSON树从正方形ID的索引（1、2、3等）开始，在每个ID中，我们有4组坐标（x1，y1等）。我的最终目标是要建立一个坐标数组，但是，我无法访问标有（x1，y1）坐标的键，并且不确定执行错误吗？任何帮助将不胜感激

main.py

with open('data.json','r') as json_file:
    coordinates = json.load(json_file)

    # We get the length of the number of objects within the json representation
    temp_length = len(coordinates)
    # For each square, access the coordinates
    for x in range (0, temp_length):
        for y in coordinates[x][0]['x1,y1']:
            print(y)

data.json

[
  {
    "1": [
      {
        "x1,y1": [
          [
            598,
            326
          ]
        ],
        "x2, y2": [
          [
            598,
            370
          ]
        ],
        "x3, y3": [
          [
            793,
            367
          ]
        ],
        "x4, y4": [
          [
            793,
            303
          ]
        ]
      }
    ]
  },
  {
    "2": [
      {
        "x1,y1": [
          [
            1005,
            170
          ]
        ],
        "x2, y2": [
          [
            1005,
            308
          ]
        ],
        "x3, y3": [
          [
            1130,
            293
          ]
        ],
        "x4, y4": [
          [
            1129,
            169
          ]
        ]
      }
    ]
  }
]

运行上面的代码时产生此错误：

Traceback (most recent call last):
  File "/Users/main.py", line 35, in <module>
    main()
  File "/Users/main.py", line 20, in main
    for y in coordinates[x][0]['x1,y1']:
KeyError: 0

Answer 1

import json

saved_coordinates = []

with open('data.json','r') as json_file:
    coordinates = json.load(json_file)

    for obj in coordinates:
        for key in obj.keys():
            for cords_list in obj[key]:
                for index, cords in cords_list.items():
                    saved_coordinates.append(cords)
                    print('index: ' + index + '\ncoordinates: ' + str(cords) + '\n')

print(saved_coordinates)

输出：

index: x4, y4
coordinates: [[793, 303]]

index: x3, y3
coordinates: [[793, 367]]

index: x2, y2
coordinates: [[598, 370]]

index: x1,y1
coordinates: [[598, 326]]

index: x4, y4
coordinates: [[1129, 169]]

index: x3, y3
coordinates: [[1130, 293]]

index: x2, y2
coordinates: [[1005, 308]]

index: x1,y1
coordinates: [[1005, 170]]

[[[793, 303]], [[793, 367]], [[598, 370]], [[598, 326]], [[1129, 169]], [[1130, 293]], [[1005, 308]], [[1005, 170]]]

Answer 2

您正在将整数传递给仅具有字符串键的字典。 0与"0"不同，您的样本数据甚至没有"0"键（仅存在"1"和"2"）。

不生成整数。只需遍历字典的值或项目即可：

for square_id, nested_list in coordinates.items():
    for coord in nested_list[0]['x1,y1']:
        print("ID:", square_id)
        print("Coordinate:", coord)

如果不需要访问密钥（在上述循环中分配给square_id），则只需使用for nested_list in coordinates.values():。

无法通过Python遍历我的JSON？

2 个答案: