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id( ) function question

 
 
raffaele ponzini
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      10-14-2009
Dear all,
I have a question concerning the output of the id() function.
In particular since is should:
""
Return the identity of an object. This is guaranteed to be unique among
simultaneously existing objects. (Hint: it's the object's memory address.)
""
i expect that for two differnt objects it returns two differnt adress in memory.

Let's seee a correct case:
>>> a=10
>>> b=20
>>> a is b

False
>>> id(a)

9986060
>>> id(b)

9985940
>>> c=a
>>> c is a

True
>>> id(c)

9986060
>>> id(a)

9986060

And now a strange (for me) output:
>>> d=10 #here i'm assingning a integer value to a fresh new variable d without any kind of link to the variable a
>>> d is a

True
>>> d==a

True
>>> id(a)

9986060
>>> id(b)

9985940
>>> id(d)

9986060
>>> a=1e10
>>> d=1e10
>>> d is a

False
>>> id(a)

11388984
>>> id(d)

11388920
>>>


--
lele
 
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