Use hex() instead of str() to build the default unique_id

This makes of a more compact and easier to compare default unique ID.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

src/frequenz/core/asyncio.py

@@ -105,11 +105,13 @@ def __init__(self, *, unique_id: str | None = None) -> None:
 
         Args:
             unique_id: The string to uniquely identify this background service instance.
-                If `None`, `str(id(self))` will be used. This is used in `__repr__` and
-                `__str__` methods, so it is used mainly for debugging purposes, to
-                identify a particular instance of a background service.
+                If `None`, a string based on `hex(id(self))` will be used. This is
+                used in `__repr__` and `__str__` methods, mainly for debugging
+                purposes, to identify a particular instance of a background service.
         """
-        self._unique_id: str = str(id(self)) if unique_id is None else unique_id
+        # [2:] is used to remove the '0x' prefix from the hex representation of the id,
+        # as it doesn't add any uniqueness to the string.
+        self._unique_id: str = hex(id(self))[2:] if unique_id is None else unique_id
         self._tasks: set[asyncio.Task[Any]] = set()
 
     @abc.abstractmethod

tests/test_asyncio.py

@@ -49,7 +49,7 @@ async def nop() -> None:
 async def test_construction_defaults() -> None:
     """Test the construction of a background service with default arguments."""
     fake_service = FakeService()
-    assert fake_service.unique_id == str(id(fake_service))
+    assert fake_service.unique_id == hex(id(fake_service))[2:]
     assert fake_service.tasks == set()
     assert fake_service.is_running is False
     assert str(fake_service) == f"FakeService[{fake_service.unique_id}]"