如何在JSONDecoder中处理空的日期字符串

import json
from datetime import datetime

class CustomJSONDecoder(json.JSONDecoder):
    def __init__(self, *args, **kwargs):
        super().__init__(object_hook=self.custom_object_hook, *args, **kwargs)

    def custom_object_hook(self, dct):
        for key, value in dct.items():
            if isinstance(value, str) and value == "":
                dct[key] = None
            elif isinstance(value, str):
                try:
                    dct[key] = datetime.strptime(value, "%Y-%m-%d")
                except ValueError:
                    pass
        return dct

# 示例数据
json_data = '{"date1": "2022-01-01", "date2": "", "date3": "2022-02-01"}'

# 使用自定义解码器解析JSON数据
decoded_data = json.loads(json_data, cls=CustomJSONDecoder)

# 输出解析结果
print(decoded_data)