fix zarr-developers#3773: Fix divergent behavior between MemoryStore and LocalStore list_prefix

Author: Claude Subagent

changes/3773.bugfix.md

@@ -0,0 +1,5 @@
+Fix divergent behavior between `MemoryStore` and `LocalStore` `list_prefix` methods.
+
+Both stores now consistently use string prefix matching (checking if keys start with the given prefix string),
+rather than `LocalStore` treating the prefix as a filesystem directory path. This ensures consistent
+behavior across different store implementations and aligns with the documented behavior of `list_prefix`.

src/zarr/storage/_local.py

@@ -290,11 +290,14 @@ async def list(self) -> AsyncIterator[str]:
 
     async def list_prefix(self, prefix: str) -> AsyncIterator[str]:
         # docstring inherited
+        # Use string prefix matching to be consistent with MemoryStore behavior.
+        # The prefix should match keys as strings, not as filesystem paths.
         to_strip = self.root.as_posix() + "/"
-        prefix = prefix.rstrip("/")
-        for p in (self.root / prefix).rglob("*"):
+        for p in list(self.root.rglob("*")):
             if p.is_file():
-                yield p.as_posix().replace(to_strip, "")
+                key = p.as_posix().replace(to_strip, "")
+                if key.startswith(prefix):
+                    yield key
 
     async def list_dir(self, prefix: str) -> AsyncIterator[str]:
         # docstring inherited