In Python 3,a = 'linux!',b = 'linux!',why id(a) is not equal id(b)?

Question

I use a = 'linux!', b = 'linux!', c = 'linux', d='linux'，Why does this happen?

 Python 3.6.3 (v3.6.3:2c5fed8, Oct  3 2017, 18:11:49) [MSC v.1900 64 bit (AMD64)] on win32
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>>> a = 'linux!'
>>> b = 'linux!'
>>> id(a)
2502413115552
>>> id(b)
2502414669112
>>> c = 'linux'
>>> d = 'linux'
>>> id(c)
2502413088616
>>> id(d)
2502413088616
>>>

Implementation details. If it ever matters, you're probably doing something wrong. — user2357112, Jan 26 '18 at 03:35

score 4 · Answer 1 · answered Jan 26 '18 at 03:36

Python can choose when to reuse immutable objects with equal values. The semantics of the language don't dictate whether a and b must be the same object or not.

Object reuse is an optimization with trade-offs. I believe strings are reused if they are likely to be identifiers, but that might just be a rumor.

In Python 3,a = 'linux!',b = 'linux!',why id(a) is not equal id(b)?

1 Answers1