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Created on 2019-11-28 03:55 by sourya varenya, last changed 2022-04-11 14:59 by admin. This issue is now closed.
| Messages (3) | |||
|---|---|---|---|
| msg357589 - (view) | Author: sourya varenya (sourya varenya) | Date: 2019-11-28 03:55 | |
Here's a sample run for reproducibility:
---
Python 3.6.9(Ubuntu 18.04) & 3.7.4(Windows)
---
>>> a = {1:{5:8},2:{5:8}}
>>> b = dict.fromkeys([1,2],{5:8})
>>> a {1: {5: 8}, 2: {5: 8}}
>>> b {1: {5: 8}, 2: {5: 8}}
>>> a[1].update({6:9})
>>> b[1].update({6:9})
>>> a {1: {5: 8, 6: 9}, 2: {5: 8}}
>>> b {1: {5: 8, 6: 9}, 2: {5: 8, 6: 9}}
|
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| msg357590 - (view) | Author: sourya varenya (sourya varenya) | Date: 2019-11-28 04:00 | |
Here's a sample run for reproducibility:
---
Python 3.6.9(Ubuntu 18.04) & 3.7.4(Windows)
---
>>> a = {1:{5:8},2:{5:8}}
>>> b = dict.fromkeys([1,2],{5:8})
>>> a
{1: {5: 8}, 2: {5: 8}}
>>> b
{1: {5: 8}, 2: {5: 8}}
>>> a[1].update({6:9})
>>> b[1].update({6:9})
>>> a
{1: {5: 8, 6: 9}, 2: {5: 8}}
>>> b
{1: {5: 8, 6: 9}, 2: {5: 8, 6: 9}}
|
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| msg357591 - (view) | Author: Josh Rosenberg (josh.r) *  |
Date: 2019-11-28 04:02 | |
That's the expected behavior, and it's clearly documented here: https://docs.python.org/3/library/stdtypes.html#dict.fromkeys Quote: "All of the values refer to just a single instance, so it generally doesn’t make sense for value to be a mutable object such as an empty list. To get distinct values, use a dict comprehension instead." |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2022-04-11 14:59:23 | admin | set | github: 83115 |
| 2019-11-28 04:02:48 | josh.r | set | status: open -> closed nosy: + josh.r messages: + msg357591 resolution: not a bug stage: resolved |
| 2019-11-28 04:00:10 | sourya varenya | set | messages: + msg357590 |
| 2019-11-28 03:55:28 | sourya varenya | create | |