Fix missing space in ValueError message

CHANGES/1295.bugfix.rst

@@ -0,0 +1,3 @@
+Fixed a missing space in the :exc:`ValueError` message
+raised when constructing a multidict from a sequence
+-- by :user:`veeceey`.

multidict/_multidict_py.py

@@ -831,7 +831,7 @@ def _parse_args(
                 for pos, item in enumerate(arg):
                     if not len(item) == 2:
                         raise ValueError(
-                            f"multidict update sequence element #{pos}"
+                            f"multidict update sequence element #{pos} "
                             f"has length {len(item)}; 2 is required"
                         )
                     identity = identity_func(item[0])

tests/test_multidict.py

@@ -294,7 +294,10 @@ def test_cannot_create_from_unaccepted(
         self,
         cls: type[MutableMultiMapping[str]],
     ) -> None:
-        with pytest.raises(ValueError, match="multidict update sequence element"):
+        with pytest.raises(
+            ValueError,
+            match=r"^multidict update sequence element #0 has length 3; 2 is required$",
+        ):
             cls([(1, 2, 3)])  # type: ignore[call-arg]
 
     def test_keys_is_set_less(self, cls: type[MultiDict[str]]) -> None: