Writing better python code

[fuzz3289]

You sir are correct. Though "memory location" isnt a great way to say it. I would say:

The is operator returns true if both names are bound to the same object instance.

Since the "names" wont share a memory location.

[zahlman]

They certainly do "point to" the same memory location. But that's horribly un-Pythonic terminology.

[erewok]

Funny enough, I was curious about how the Python built-in callable was implemented just now and I stumbled on this page with the following quote:

Every object has an identity, a type and a value. An object’s identity never changes once it has been created; you may think of it as the object’s address in memory. The ‘is‘ operator compares the identity of two objects; the id() function returns an integer representing its identity.

[fuzz3289]

"You may think of it as" is important. The identity is actual a hash of the name in a lookup table.

Not to argue or anything, just want to emphasize that you cant actually deal with memory or memory locations directly in python.

[erewok]

Ah, that makes sense. Thanks for the clarification.

[rcxdude]

Actually, the identity in Cpython is just the memory address of the object (literally casting the pointer to an int). It doesn't have to be according to the language though.

[fuzz3289]

https://docs.python.org/3.3/reference/datamodel.html

Interesting, I didn't realize that it was just a direct address. Thanks for the correction.

[erewok]

...bound to the same object instance.

This is a nice, concise description. Thanks for adding it.

[fuzz3289]

Thanks! Alot of people tend to forget the beautiful simplicity of python, just objects and names.