add dataset

csst_dfs_client/plan.py

 import os
 from typing import Optional, IO, Tuple, Literal, Union
-from .common import request, Result
-
+from .common import request, Result, constants
 DateTimeTuple = Tuple[str, str]
 
 def find(mode: Optional[str] = None,
@@ -12,6 +11,7 @@ def find(mode: Optional[str] = None,
         obs_type: Optional[str] = None,
         object_name: Optional[str] = None,
         obstime: Optional[DateTimeTuple] = None,
+        dataset: str = constants.DEFAULT_DATASET,
         page: int = 1,
         limit: int = 0) -> Result:
     """
@@ -25,7 +25,8 @@ def find(mode: Optional[str] = None,
         file_type (Optional[str], optional): 文件类型，如'SCI'. Defaults to None.
         obs_type (Optional[str], optional): 观测类型，如主巡天宽场、TOO观测、定标星场等等. Defaults to None.
         object_name (Optional[str], optional): 目标名称. Defaults to None.
-        obstime (Optional[DateTimeTuple], optional): 观测时间范围. Defaults to None.
+        obstime (Optional[DateTimeTuple], optional): 观测时间范围. 如("2021-08-30 00:00:00", "2024-12-30 23:59:59")，Defaults to None. 
+        dataset (Optional[str], optional): 数据集名称. Defaults to constants.DEFAULT_DATASET.
         page (int, optional): 页码. Defaults to 1.
         limit (int, optional): 每页数量. Defaults to 0，不限制.
     
@@ -46,6 +47,7 @@ def find(mode: Optional[str] = None,
         'obs_time_end': None,
         'create_time_start': None,
         'create_time_end': None,
+        'dataset': dataset,
         'page': page,
         'limit': limit,
     }