resolve case of string restrictions

src/spyglass/utils/dj_merge_tables.py

@@ -3,7 +3,7 @@
 from pprint import pprint
 from re import sub as re_sub
 from time import time
-from typing import Union
+from typing import Union, List
 
 import datajoint as dj
 from datajoint.condition import make_condition
@@ -532,16 +532,17 @@ def fetch_nwb(
         if isinstance(self, dict):
             raise ValueError("Try replacing Merge.method with Merge().method")
         restriction = restriction or self.restriction or True
-        sources = set((self & restriction).fetch(self._reserved_sk))
+        merge_restriction = extract_merge_id(restriction)
+        sources = set((self & merge_restriction).fetch(self._reserved_sk))
         nwb_list = []
         merge_ids = []
         for source in sources:
             source_restr = (
-                self & {self._reserved_sk: source} & restriction
+                self & {self._reserved_sk: source} & merge_restriction
             ).fetch("KEY")
             nwb_list.extend(
                 (self & source_restr)
-                .merge_restrict_class(restriction, permit_multiple_rows=True)
+                .merge_restrict_class(restriction, permit_multiple_rows=True, add_invalid_restrict=False)
                 .fetch_nwb()
             )
             if return_merge_ids:
@@ -737,10 +738,10 @@ def merge_get_parent_class(self, source: str) -> dj.Table:
         return ret
 
     def merge_restrict_class(
-        self, key: dict, permit_multiple_rows: bool = False
+        self, key: dict, permit_multiple_rows: bool = False, add_invalid_restrict=True
     ) -> dj.Table:
         """Returns native parent class, restricted with key."""
-        parent = self.merge_get_parent(key)
+        parent = self.merge_get_parent(key, add_invalid_restrict=add_invalid_restrict)
         parent_key = parent.fetch("KEY", as_dict=True)
 
         if not permit_multiple_rows and len(parent_key) > 1:
@@ -860,3 +861,35 @@ def delete_downstream_merge(
     table = table if isinstance(table, dj.Table) else table()
 
     return table.delete_downstream_parts(**kwargs)
+
+def extract_merge_id(restriction):
+    """Utility function to extract merge_id from a restriction
+
+    Parameters
+    ----------
+    restriction : str, dict, or dj.condition.AndList
+        A datajoint restriction
+
+    Returns
+    -------
+    restriction
+        A restriction containing only the merge_id key
+    """
+    if restriction is None:
+        return None
+    if isinstance(restriction, dict):
+        if merge_id := restriction.get("merge_id"):
+            return {"merge_id": merge_id}
+        else:
+            return {}
+    merge_restr = []
+    if isinstance(restriction, dj.condition.AndList) or isinstance(restriction, List):
+        merge_id_list = [extract_merge_id(r) for r in restriction]
+        merge_restr =  [x for x in merge_id_list if x is not None]
+    elif isinstance(restriction, str):
+        parsed = [x.split(")")[0] for x in restriction.split("(") if x]
+        merge_restr =  dj.condition.AndList([x for x in parsed if "merge_id" in x])
+
+    if len(merge_restr) == 0:
+        return True
+    return merge_restr