Pointer or unique id

[Nomak]

Hello,

does python have an equivalent to Java: int Object.hashCode() ?

TIA

 

[Bruno Desthuilliers]

Nomak a écrit :

Hello,

does python have an equivalent to Java: int Object.hashCode() ?

id(object) -> integer
Return the identity of an object. This is guaranteed to be unique among
simultaneously existing objects. (Hint: it's the object's memory address.)

hash(obj) -> integer
Return a hash value for the object. Two objects with the same value
have the same hash value. The reverse is not necessarily true, but likely.

HTH
Bruno

 

[Michael Hoffman]

hash(obj) -> integer
Return a hash value for the object. Two objects with the same value
have the same hash value. The reverse is not necessarily true, but likely.

Of course not all Python objects are hashable:

>>> hash([])

Traceback (most recent call last):
File "<stdin>", line 1, in ?
TypeError: list objects are unhashable

 

[Terry Reedy]

id(object) -> integer
Return the identity of an object. This is guaranteed to be unique among
simultaneously existing objects.

This is part of the language specification. Also, the identity of an
object must remain the same for its entire lifetime.

(Hint: it's the object's memory address.)

This is an implementation detail of CPython. It cannot be true if the
garbage collector moves objects around. Or if the object lives elsewhere
(and is accessed thru a proxy).

Terry J. Reedy