On 16/6/2013 9:53 μμ, R. Michael Weylandt wrote:
On Sun, Jun 16, 2013 at 2:47 PM, Ferrous Cranus <supp...@superhost.gr> wrote:
On 16/6/2013 2:13 μμ, Jussi Piitulainen wrote:
If, instead of the above, you have
a = 6
b = a
b = 5
you will find that b == 5 and a == 6. So b is not the same as a. Else
one would have changed when the other changed. I would say that a and
b are different variables. They had the same value, briefly.
If they were different variables then they would have different memory
addresses and they would act like two different objects.
But... both a and b are for a fact mappings for the same memory address as
seen form the following command.
id(a) == id(b)
True
They are like the same object with 2 different names.
This will depend on when the test is run:
a = 6
b = a
a is b # True
b = 5
a is b # False
The latter is false because the binding of "b" to the int 6 was broken
in order to bind b to the int 5.
Very surprising.
a and b was *references* to the same memory address, it was like a
memory address having 2 names to be addresses as.
b = a name we use to address some memory location, do we agree on that?
So, b = 6, must have changed the stored value of its mapped memory
location, but given you example it seems its changing the mapping of b
to some other memory address.
I don't follow its act of course.
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What is now proved was at first only imagined!
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