Created on 2010-02-11 15:26 by mattrussell, last changed 2010-02-11 17:45 by rhettinger. This issue is now closed.
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| msg99219 - (view) | Author: Matthew Russell (mattrussell) | Date: 2010-02-11 15:26 | |
Tuples, as we know are designed to immutable. Hence I'm questioning if the following behavior is considered a defect: >>> t = (1, 2) >>> t += (1, 2, 3) >>> t (1, 2, 3) ? |
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| msg99220 - (view) | Author: Jean-Paul Calderone (exarkun) *  |
Date: 2010-02-11 15:28 | |
Your output looks fishy. Anyway, the behavior of += isn't a bug: >>> a = b = (1, 2) >>> a += (1, 2, 3) >>> a (1, 2, 1, 2, 3) >>> a is b False >>> It's confusing, to be sure, but no mutation is going on. += is only in-place if applied to something that supports mutation this way (by implementing __iadd__). |
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| msg99221 - (view) | Author: Tim Golden (tim.golden) |
Date: 2010-02-11 15:32 | |
Just think about it for a minute: t = (1, 2) print id (t), t t += (1, 2, 3) print id (t), t Not mutating, merely creating a new new object and giving it the same name |
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| msg99225 - (view) | Author: Matthew Russell (mattrussell) | Date: 2010-02-11 15:40 | |
Yes, the output is fishy indeed my bad (paste error). Tim: I hadn't thought for long enough or thought to check with the id builtin - nice catch. |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2010-02-11 17:45:27 | rhettinger | set | resolution: invalid |
| 2010-02-11 15:40:19 | mattrussell | set | status: open -> closed messages: + msg99225 |
| 2010-02-11 15:32:40 | tim.golden | set | nosy:
+ tim.golden messages: + msg99221 |
| 2010-02-11 15:28:21 | exarkun | set | nosy:
+ exarkun messages: + msg99220 |
| 2010-02-11 15:26:27 | mattrussell | create | |