一 样例1 json文件只有一个样本

1 json文件内容

{
  "version": "4.5.7",
  "flags": {},
  "shapes": [
    {
      "label": "car",
      "points": [
        [
          737.3076923076923,
          244.8461538461538
        ],
        [
          1028.076923076923,
          555.6153846153846
        ]
      ],
      "group_id": null,
      "shape_type": "rectangle",
      "flags": {}
    }
  ],
  "imagePath": "..\\..\\images\\train2017\\000001.jpg",
  "imageData": "/9j/4AAQSkZJR"

2 代码转化

读取文件夹，将json文件转化为txt文件，即将JSON的关键数据读出

import os
import json


json_dir = 'C:/Users/YourName/Desktop/coco128/labels/train2017/'  # json文件路径
out_dir = 'C:/Users/YourName/Desktop/output/'  # 输出的 txt 文件路径

def get_json(json_file, filename):
    # 读取 json 文件数据
    with open(json_file, 'r') as load_f:
        content = json.load(load_f)
    
    # # 循环处理
    tmp = filename
    filename_txt = out_dir + tmp + '.txt'
    #创建txt文件
    fp = open(filename_txt, mode="w", encoding="utf-8")
    #将数据写入文件
    # 计算 yolo 数据格式所需要的中心点的 相对 x, y 坐标, w,h 的值
    x = (content["shapes"][0])["points"][0][0]  
    y = (content["shapes"][0])["points"][0][1] 
    w = (content["shapes"][0])["points"][1][0] - (content["shapes"][0])["points"][0][0] 
    h = (content["shapes"][0])["points"][1][1] - (content["shapes"][0])["points"][0][1]
    fp = open(filename_txt, mode="r+", encoding="utf-8")
    file_str = str(filename) + ' ' + str(round(x, 6)) + ' ' + str(round(y, 6)) + ' ' + str(round(w, 6)) + \
            ' ' + str(round(h, 6))
    line_data = fp.readlines()

    if len(line_data) != 0:
        fp.write('\n' + file_str)
    else:
        fp.write(file_str)
    fp.close()


def main():
    files= os.listdir(json_dir) #得到文件夹下的所有文件名称
    s = []
    for file in files: #遍历文件夹
        filename = file.split('.')[0]
        # print(tmp)
        get_json(json_dir+file, filename)
    


if __name__ == '__main__':
    main()

3 效果图

原：
改后：

txt内容：

二 样例2 json文件中有多个样本

1 json文件内容

{
  "version": "3.16.2",
  "flags": {},
  "shapes": [
    {
      "label": "00000001",
      "line_color": null,
      "fill_color": null,
      "points": [
        [
          167.0,
          114.0
        ],
        [
          146.0,
          142.0
        ],
        [
          177.0,
          145.0
        ],
        [
          214.0,
          129.0
        ],
        [
          210.0,
          102.0
        ],
        [
          185.0,
          107.0
        ]
      ],
     "shape_type": "polygon",
      "flags": {}
    },
    {
      "label": "00004702",
      "line_color": null,
      "fill_color": null,
      "points": [
        [
          306.0,
          71.0
        ],
        [
          289.0,
          109.0
        ],
        [
          321.0,
          112.0
        ],
        [
          359.0,
          78.0
        ],
        [
          329.0,
          57.0
        ]
      ],
      "shape_type": "polygon",
      "flags": {}
    }
  ],
"lineColor": [
    0,
    255,
    0,
    128
  ],
  "fillColor": [
    255,
    0,
    0,
    128
  ],
  "imagePath": "048.jpg",
  "imageData": "/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0a"
}

2 代码转化

import os
import json


json_dir = 'C:/Users/YourName/Desktop/coco/jsonDir/'  # json文件路径
out_dir = 'C:/Users/YourName/Desktop/coco/outputDir/'  # 输出的 txt 文件路径

def get_json(json_file, filename):
    # 读取 json 文件数据
    with open(json_file, 'r') as load_f:
        content = json.load(load_f)
    
    # # 循环处理
    tmp = filename
    filename_txt = out_dir + tmp + '.txt'
    #创建txt文件
    fp = open(filename_txt, mode="w", encoding="utf-8")
    #将数据写入文件
    str_tmp = "" #存储字符串内容
    #1.获取version、flags数据
    version = content["version"]
    flags = content["flags"]
    #暂存内容
    str_tmp = str(version)+"\n"+str(flags)+"\n"

    #2. 获取shapes数组中的数据
    #循环读取 shapes中的每一组数据，json文件中有2组数据，循环则是2个 [0,1]
    for i in range(2):
      label = (content["shapes"][i])["label"]
      line_color = (content["shapes"][i])["line_color"]
      fill_color = (content["shapes"][i])["fill_color"]
      str_tmp += str(label) + "\n" + str(line_color) + "\n"  + str(fill_color) + "\n"  ##暂存内容
      #读取points中的数据，有6组数据
      points_size = len((content["shapes"][i])["points"])
      for j in range(points_size):
          x = (content["shapes"][i])["points"][j][0]
          y = (content["shapes"][i])["points"][j][1]
          str_tmp += str(x) + "        " + str(y) + "\n"  ##暂存内容
      #读取shape_type,flags
      shape_type = (content["shapes"][i])["shape_type"]
      flags = (content["shapes"][i])["flags"]
      str_tmp += str(shape_type) + "        " + str(flags) + "\n"  ##暂存内容
    #3. 获取lineColor、fillColor、imagePath、imageData
    line_Color = content["lineColor"]
    fill_Color = content["fillColor"]
    imagePath = content["imagePath"]
    imageData = content["imageData"]

    #lineColor是数组，获取并存储lineColor
    for i in range(len(line_Color)):
        str_tmp += str(line_Color[i]) + "   "
    str_tmp += "\n" #换行效果
    #fillColor与lineColor一样，也为数组，获取并存储fillColor
    for i in range(len(fill_Color)):
        str_tmp += str(fill_Color[i]) + "   "
    str_tmp += "\n" #换行效果
    str_tmp += str(imagePath) + "        " + str(imageData) + "\n"  ##暂存内容
    fp = open(filename_txt, mode="r+", encoding="utf-8")
    file_str = str_tmp
    line_data = fp.readlines()

    if len(line_data) != 0:
        fp.write('\n' + file_str)
    else:
        fp.write(file_str)
    fp.close()


def main():
    files= os.listdir(json_dir) #得到文件夹下的所有文件名称
    s = []
    for file in files: #遍历文件夹
        filename = file.split('.')[0]
        # print(tmp)
        get_json(json_dir+file, filename)
    


if __name__ == '__main__':
    main()

3 效果图

三 样例3 json文件单样本

1 json文件内容

{"marks":[[240.47823834196888,57.812953367875636],[226.80673575129526,388.58290155440415],[235.33316062176164,227.56113989637305]],"slots":[[3,1, 1,90],[2,3,1,90]]}

2 代码转化

import os
import json

json_dir = 'C:/Users/YourName/Desktop/train/'  # 放json文件路径，train是放json文件的文件夹
out_dir = 'C:/Users/YourName/Desktop/output/'  # 输出的 txt 文件路径，output是放txt文件的文件夹

def get_json(json_file, filename):
    # 读取 json 文件数据
    with open(json_file, 'r') as load_f:
        content = json.load(load_f)
    
    # # 循环处理
    tmp = filename
    filename_txt = out_dir + tmp + '.txt'
    #创建txt文件
    fp = open(filename_txt, mode="w", encoding="utf-8")
    #将数据写入文件
    #首先是mark，二维数组3*2，提取数据如下
    x1y1 = content["marks"][0][0]
    x1y2 = content["marks"][0][1]
    x2y1 = content["marks"][1][0]
    x2y2 = content["marks"][1][1]
    x3y1 = content["marks"][2][0]
    x3y2 = content["marks"][2][1]
    #slots为2*4的二维数组,提取数据如下
    s_x1y1 = content["slots"][0][0]
    s_x1y2 = content["slots"][0][1]
    s_x1y3 = content["slots"][0][2]
    s_x1y4 = content["slots"][0][3]
    s_x2y1 = content["slots"][1][0]
    s_x2y2 = content["slots"][1][1]
    s_x2y3 = content["slots"][1][2]
    s_x2y4 = content["slots"][1][3]
    #数据写入txt文档
    fp = open(filename_txt, mode="r+", encoding="utf-8")
    file_str = str(filename) + '\n' + str(round(x1y1, 6)) + ' ' + str(round(x1y2, 6)) + ' ' +\
    str(round(x2y1, 6)) + ' ' + str(round(x2y2, 6)) + str(round(x3y1, 6)) + ' ' +  \
    str(round(x3y2, 6)) + '\n' + str(round(s_x1y1, 6)) +' ' + str(round(s_x1y2, 6)) + ' ' + \
    str(round(s_x1y3, 6)) + ' ' + str(round(s_x1y4, 6)) +' ' + str(round(s_x2y1, 6)) + \
    str(round(s_x2y2, 6)) + ' ' + str(round(s_x2y3, 6)) +' ' + str(round(s_x2y4, 6))   
    line_data = fp.readlines()

    if len(line_data) != 0:
        fp.write('\n' + file_str)
    else:
        fp.write(file_str)
    fp.close()


def main():
    files= os.listdir(json_dir) #得到文件夹下的所有文件名称
    s = []
    for file in files: #遍历文件夹
        filename = file.split('.')[0]
        # print(tmp)
        get_json(json_dir+file, filename)
    


if __name__ == '__main__':
    main()

3 效果图