[Tutor] Python Memory Allocation -- deep learning

Steven D'Aprano steve at pearwood.info
Mon Jul 30 13:10:28 EDT 2018

On Mon, Jul 30, 2018 at 09:21:01AM -0600, Mats Wichmann wrote:

> (id does not necessarily mean memory location, by the way)

id() *never* means memory location in Python. id() *always* returns an 
opaque integer ID number which has no promised meaning except to be 
unique while the object is alive.

The interpreter has to generate an ID somehow. In Jython and IronPython, 
the interpreter keeps a counter, and IDs are allocated as consecutive 
numbers 1, 2, 3, 4, ... etc. In CPython, the object's memory address is 
used to generate the ID, but the ID does not mean "memory address". If 
the ID happens to match the memory address, that's an accident, not a 
feature of the language.


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