python type_error ai_generated true

类型错误：类型为 'Decimal' 的对象不可JSON序列化

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

ID: python/flask-jsonify-error-nonserializable

其他格式: JSON · Markdown 中文 · English
80%修复率
85%置信度
0证据数
2025-07-22首次发现

版本兼容性

版本状态引入弃用备注
3.x active — — —

根因分析

Flask的jsonify使用默认JSON编码器，无法序列化Decimal。

English

Flask's jsonify uses default JSON encoder which cannot serialize Decimal.

generic

解决方案

  1. 90% 成功率 Create a custom JSON encoder and set it on the Flask app. 
    from flask import Flask, jsonify
from json import JSONEncoder
class CustomEncoder(JSONEncoder):
    def default(self, obj):
        if isinstance(obj, Decimal):
            return str(obj)
        return super().default(obj)
app = Flask(__name__)
app.json_encoder = CustomEncoder
  2. 85% 成功率 Convert Decimal to string in the data before jsonify. 
    data = {'price': str(decimal_value)}
return jsonify(data)

无效尝试

常见但无效的做法:

  1. Converting Decimal to float manually, losing precision. 60% 失败

    Float may introduce rounding errors for financial data.

  2. Using json.dumps with default=str but not integrating with jsonify. 70% 失败

    jsonify does not use the same encoder as json.dumps by default.