【文件处理】TypeError: Object of type ‘ndarray‘ is not JSON serializable错误解决方法

一、将字典写入json文件

import json

test_dict = {
    'version': "1.0",
    'explain': {
        'used': True,
        'details': "this is for josn test",
  }
}

#将字典转换为字符串形式
json_str = json.dumps(test_dict, indent=4)#注意这个indent参数，可以保存字典的缩进格式，否则为一行

with open('test_data.json', 'w') as json_file:
     json_file.write(json_str)

二、json文件中读取字典

with open('test_data.json', 'r') as json_file:
	dic = json.load(json_file)

三、将字典写入TXT文件中

import json

dic = {  
    'andy':{  
        'age': 23,  
        'city': 'beijing',  
        'skill': 'python'  
    },  
    'william': {  
        'age': 25,  
        'city': 'shanghai',  
        'skill': 'js'  
    }  
}  

js = json.dumps(dic)   
file = open('test.txt', 'w')  
file.write(js)  
file.close()

四、从TXT中读取字典

import json

file = open('test.txt', 'r') 
js = file.read()
dic = json.loads(js)   
print(dic) 
file.close()

五、解决字典含数组存入json文件失败的方法

因为json无法序列化

1、存入前将数组变成列表

array.tolist()

2、扩展类方法

class NpEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, np.integer):
            return int(obj)
        elif isinstance(obj, np.floating):
            return float(obj)
        elif isinstance(obj, np.ndarray):
            return obj.tolist()
        else:
            return super(NpEncoder, self).default(obj)

将上述代码添加到你的代码中，然后改成json.dumps(data, cls=NpEncoder)

TypeError: Object of type 'ndarray' is not JSON serializable

from collections import defaultdict
import json
import numpy as np

class NpEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, np.integer):
            return int(obj)
        elif isinstance(obj, np.floating):
            return float(obj)
        elif isinstance(obj, np.ndarray):
            return obj.tolist()
        else:
            return super(NpEncoder, self).default(obj)


video = defaultdict(list)
video["label"].append("haha")
video["data"].append(234)
video["score"].append(0.3)
video["label"].append("xixi")
video["data"].append(123)
video["score"].append(0.7)

test_dict = {
    'version': "1.0",
    'results': (np.zeros((2,3))),
    'explain': {
        'used': True,
        'details': "this is for josn test",
  }
}
print(test_dict)
json_str = json.dumps(test_dict, indent=4,cls=NpEncoder)#注意这个indent参数
with open('test_data.json', 'w') as json_file:
     json_file.write(json_str)

with open('test_data.json', 'r') as json_file:
	dic = json.load(json_file)
print(type(dic))

参考：

https://blog.csdn.net/li532331251/article/details/78203438

https://blog.csdn.net/BobChill/article/details/83864285