Python "is" behavior

["Martin v. Löwis"]

> For some reason, stacking multiple statements reuses the same object.

Each code object has a co_consts tuple referring to all constants used
in the code. The compiler interns duplicate constants for a single
compiler run, resulting in the same object being used when the code
is put into a single line (or in a function, or module).

When the code is split into multiple interactive statements, the
compiler runs multiple times, and doesn't know anything about past
runs.

Regards,
Martin