Issue 22779: deque in-place addition does not return NotImplemented when appropriate
--> from collections import deque --> d = deque() --> d += 1 Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'int' object is not iterable deque should be returning NotImplemented, which would generate a more appropriate error message: TypeError: unsupported operand type(s) for -=: 'collections.deque' and 'int' which is what happens with -=, *=, /=, |=, at which point I stopped testing.