Question

我是python的新手，非常感谢您的帮助。我有一个包含键值对的JSON文件，基本上我必须提取'regions'中存在的'all_points_x'和'all_points_y'。我创建了一个循环，但我没有给出正确的键来提取'regions'，请需要你的帮助解决问题。 json_data文件内容

_via_img_metadata {'barley_Admixture_image28.jpg2218': {'filename': 'barley_Admixture_image28.jpg', 'size': 2218, 'regions': [{'shape_attributes': {'name': 'polygon', 'all_points_x': [35, 28, 27, 31, 40, 51, 62, 72, 74, 71, 65, 57, 41], 'all_points_y': [74, 55, 32, 16, 4, 6, 12, 35, 56, 74, 83, 86, 81]}, 'region_attributes': {}},

for i in range(len(json_data[keys]['regions'])):
            coords = []
            for j in range(len(json_data[keys]['regions'][i]['shape_attributes']['all_points_x'])):
                coords.append((json_data[keys]['regions'][i]['shape_attributes']['all_points_x'][j], json_data[keys]['regions'][i]['shape_attributes']['all_points_y'][j]))
            coords = np.asarray([coords], dtype=np.int32)
            if i == 0:
                mask = np.zeros((image.shape[0], image.shape[1]), dtype=np.uint8)
                cv2.polylines(mask, coords, isClosed=True, color=255, thickness=4)
            else:
                mask1 = np.zeros((image.shape[0], image.shape[1]), dtype=np.uint8)
                cv2.polylines(mask1, coords, isClosed=True, color=255, thickness=4)
                mask = cv2.bitwise_or(mask,mask1)

Answer 1

您可以像这样访问嵌套词典中的项目

for key,value in dictionary.items():
    for k,v in value.items()
        #do sth

据我了解，您的json_data下面的代码应该可以工作。

coords = []

for key,value in json_data.items():
    regions = value['regions']
    for i in range(len(regions)):
        for x,y in zip(regions[i]['shape_attributes']['all_points_x'],regions[i]['shape_attributes']['all_points_y']):
            coords.append((x,y))

Answer 2

尝试以下操作以提取all_points_x和all_points_y元组，我假设您的json为input_json：

input_keys = input_json.keys()
for key in input_keys:
    for obj in input_json[key]['regions']:
        for i in range(len(obj['shape_attributes']['all_points_x'])):
            coords.append((obj['shape_attributes']['all_points_x'][i], obj['shape_attributes']['all_points_y'][i]))
print(coords)

如何在嵌套字典python中访问元素

2 个答案: