Fix parse_uid() for model names with dots

src/petals/data_structures.py

@@ -1,4 +1,5 @@
 import dataclasses
+import re
 from enum import Enum
 from typing import Any, Dict, Optional, Sequence, Tuple
 
@@ -13,8 +14,9 @@
 
 def parse_uid(uid: ModuleUID) -> Tuple[str, int]:
     assert CHAIN_DELIMITER not in uid, "parse_uid() does not support chained UIDs"
-    dht_prefix, index = uid.split(UID_DELIMITER)
-    return dht_prefix, int(index)
+    match = re.fullmatch(fr"(.+){re.escape(UID_DELIMITER)}(\d+)", uid)
+    assert match is not None, f"uid={uid!r} has invalid format"
+    return match.group(1), int(match.group(2))
 
 
 @pydantic.dataclasses.dataclass