Array element id changes in ipython

Question

Why does the array element id keep changing?

    In [43]: x = np.array([[1,2,3],[4,5,6],[7,8,9]])
    In [44]: print id(x[0])
    30836416
    In [45]: print id(x[0])
    31121344
    In [46]: print id(x[0])
    31471808

IPython Screenshot

This is not the case when it is written in python script. When writing in python script, we get the same identifier

Other observations are shown in the figure below.

aCopy is a copy of the array a. id for the same element of both arrays is printed twice. According to the results, the id of all elements of the array, regardless of whether it can be the same array or another (copy), except for FIRST printing. Why is the id of the same element from two different arrays the same? Why is one of the identifiers different when printing several times?

Answer 1

id() CPython .

, , , x[0], . , . ​​

IPython, , , , x[0] .

IPython , :

In [28]: print id(x[0]); print id(x[0])
140000637403008
140000637403008

In [29]: print id(x[0]); print id(x[0])
140000637402608
140000637402608

In [30]: print id(x[0]); print id(x[0])
140000637402928
140000637402928

, .

Answer 2

id(x[0]) - , x.__getitem__(0). numpy- , , , , . id x.data, . array . , .. .

, SO .

python id

"" . , . id().

id, non-overlapping lifetimes.