效果：

使用方法：

1，放在目录下双击运行

2，目录下打开cmd，传入参数 log，可以保存日志，查看结果

mod_json.exe log

?3，源码

# -*- coding:utf-8 -*-
import json
import sys
import os
import shutil
from pip._vendor.distlib.compat import raw_input

def mod_jsonVal(file,logFlag,logFile):
    with open(file,encoding="utf-8") as f:
        data = json.load(f)

        # 每张图
        for jpgIndex,jpg in enumerate(data['_via_img_metadata']):
            flag = False
            # 一张图中的每个框
            regions = data['_via_img_metadata'][jpg]['regions']

            # 筛选 图中的每个矩形框 rect
            for index,r in enumerate(regions):
                if (r['shape_attributes']['name'] == "rect"):

                    s = '{} {} {} {}'.format("原数据",index,":",regions[index])
                    print(s)
                    save_log(logFlag,logFile,s)

                    # 矩形数据转化四边形数据
                    regions[index]['shape_attributes'] = mod_RectToPolygon(regions,index, r)

                    s1 = '{} {} {} {}'.format("修改后", index, ":", regions[index])
                    print(s1)
                    save_log(logFlag,logFile,s1)

                    flag = True

            if flag:
                save_newVal(data, file)
                s = '{}{} {}'.format(jpg, jpgIndex + 1, "有矩形，已修改\n")
                print(s)
                save_log(logFlag,logFile,s)
            else:
                s = '{}{} {}'.format(jpg, jpgIndex+1,"没有发现矩形，无需修改")
                print(s)
                save_log(logFlag,logFile, s)

# 数据重组 矩形转四边形
def mod_RectToPolygon(regions,index,r):
    '''{'name': 'rect', 'x': 477, 'y': 905, 'width': 92, 'height': 42} 转换成如下
    {'name': 'polygon', 'all_points_x': [477, 569, 569, 477], 'all_points_y': [905, 905, 946, 946]}'''

    # 取得矩形的有效值
    x = r['shape_attributes']['x']
    y = r['shape_attributes']['y']
    width = r['shape_attributes']['width']
    height = r['shape_attributes']['height']

    # 矩形转换成多边形数据
    j = {"name": "polygon", "all_points_x": '', "all_points_y": ''}
    # 必须转化为json，否则会变成字符串 --> 'all_points_x': [2606, 2652, 2652, 2606]
    j['all_points_x'] = json.loads("[" + str(x) + "," + str(x + width) + "," + str(x + width) + "," + str(x) + "]")
    j['all_points_y'] = json.loads("[" + str(y) + "," + str(y) + "," + str(y + height) + "," + str(y + height) + "]")

    return j

# 保存新的json
def save_newVal(data1,file):
    with open(file, 'w',encoding='utf-8') as f:
        json.dump(data1, f, ensure_ascii=False, separators=(',', ':'))

# 遍历 含子目录，筛出 json 文件，并且备份
def list_all_files(rootdir):
    _files = []
    list = os.listdir(rootdir)  # 列出文件夹下所有的目录与文件
    for i in range(0, len(list)):
        path = os.path.join(rootdir, list[i])
        # 是目录则重新调用本方法，递归
        if os.path.isdir(path):_files.extend(list_all_files(path))

        # 取得文件，筛出 json 文件
        if os.path.isfile(path) and os.path.splitext(path)[1] == ".json":
            _files.append(path)

            # 备份，已备份则跳过。在原目录下
            bak = path+".bak"
            if not os.path.isfile(bak):
                shutil.copy(path,bak)
                print("备份了:",bak)

            # 删除备份
            # if os.path.isfile(path+".bak"):os.remove(path+".bak")

    return _files

# 日志保存
def save_log(l,logpath,logs):
    if (l): open(logpath, "a").write('{}'.format(logs+'\n'))

# 1.遍历目录，含子目录
# 2.备份
# 3.重组json数据
# 4.日志保存（可选）

# currPath = "E:\\cdzj\\文本行检测标注-test\\文本行检测标注-693"
currPath = os.path.abspath('.').replace("\\","\\\\") # 转义
raw_input("处理当前目录 "+currPath+" (含子目录)下的所有 json文件，按回车确认！") #回车等待确认

# 是否使用日志。如果传入的参数是 log ，就保存日志到json文件同目录下
for _fs in list_all_files(currPath):
    if(len(sys.argv) ==2 ):
        if (sys.argv[1] == "log"):
            print("\n" + _fs)
            logFile = _fs.replace("json", "log.txt")  # 日志文件完整路径
            save_log(True, logFile, _fs + "\n")
            mod_jsonVal(_fs, True, logFile)
    else:
        mod_jsonVal(_fs, False, _fs.replace("json", "log.txt"))

# 等待回车退出
print("\n为了保证结果可用性，不妨重新加载项目看看，检查矩形是否成功转换为矩形")
raw_input("\n按回车退出！每次运行时传入参数 log 可以保存日志哦 「红叶」\n")

下载：

mod_json.exe