[New-bugs-announce] [issue29552] Issue in Dictionary fromkeys

[Prudvi Mangadu]

New submission from Prudvi Mangadu:

If we load the keys and values using fromkeys on dic.
Later the modification in the values is reflects for all keys in the DIC, please follow the below code.

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PS C:\Python27> py
Python 2.7.10 (default, May 23 2015, 09:40:32) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>> input = ['1','2']
>>> result = {}
>>> result = result.fromkeys(input,[])  >>>> Issue with this line
>>>
>>> result
{'1': [], '2': []}
>>>
>>> result['1'].append("item1")
>>>
>>> result
{'1': ['item1'], '2': ['item1']}   >>>>>>>>>>>>>>>>>> Here result['2'] also overwrites
>>>
>>> result['1'].append("item2")    
>>> result
{'1': ['item1', 'item2'], '2': ['item1', 'item2']}   >>>>>>>>>>>>>>>>>> Here result['2'] also overwrites
>>>
>>>
#######################################################################################

----------
components: Windows
messages: 287747
nosy: paul.moore, prudvibt81, steve.dower, tim.golden, zach.ware
priority: normal
severity: normal
status: open
title: Issue in Dictionary fromkeys
type: behavior
versions: Python 2.7

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue29552>
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