identity is guaranteed:
1) Assignments create new names but do not change object identity. After the
-assignment ``new = old``, it is guaranteed that ``new is old``.
+ assignment ``new = old``, it is guaranteed that ``new is old``.
2) Putting an object in a container that stores object references does not
-change object identity. After the list assignment ``s[0] = x``, it is
-guaranteed that ``s[0] is x``.
+ change object identity. After the list assignment ``s[0] = x``, it is
+ guaranteed that ``s[0] is x``.
3) If an object is a singleton, it means that only one instance of that object
-can exist. After the assignments ``a = None`` and ``b = None``, it is
-guaranteed that ``a is b`` because ``None`` is a singleton.
+ can exist. After the assignments ``a = None`` and ``b = None``, it is
+ guaranteed that ``a is b`` because ``None`` is a singleton.
In most other circumstances, identity tests are inadvisable and equality tests
are preferred. In particular, identity tests should not be used to check