TypeError: Object of type 'int32' is not JSON serializable

将 list 数据转化为json格式时报错：
TypeError: Object of type 'int32' is not JSON serializable

解决方法：
重写json.JSONEncoder

import np as numpy
import json
class MyEncoder(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(MyEncoder, self).default(obj)

data = json.dumps(data,cls=MyEncoder)