[issue39110] UserList-subclass Tree slicing changes node attribute

[ctarn]

ctarn <i at ctarn.io> added the comment:

Sorry but it is not. See the first time I print ls[4].owner. We get d as expected, not a slice of d, that is, d[0:2].

However the next time we print it after _ = list(d[0:1]), noticed that ls[4] == d[0:1], we get d[0:1], it’s extremely surprising!!!

I have to highlight it: we just print *.owner before and after `_ = list(d[0:1])`, and the results are different!!!

The latest 3 lines show more strange results.

By the way, it’s my first time to report bug, and I don’t know what is discussion list, and reopened the issue. Thank you.

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status: closed -> open

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue39110>
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