Dictionary problem

Alex Martelli aleax at aleax.it
Mon Nov 17 18:09:17 CET 2003


<posted & mailed>

Elena Schulz wrote:

> myList = []
> for i in range(3) :
>     myDict['id']=i
>     myList.append(myDict)
> 
> myList becomes: [{'id':2}, {'id':2}, {'id':2}] but I want: [{'id':0},
> {'id':1}, {'id':2}]

So, you don't want to append myDict itself, but, rather, a copy of it.

> thanx for any hint how to achieve that

Instead of:

    myList.append(myDict)

which appends myDict itself, append a copy, e.g.:

    myList.append(myDict.copy())

or

    myList.append(dict(myDict))

Python doesn't make copies by default: when you want a copy, you ask
for one explicitly, as in these two examples.

> (Please answer to my mail address directly as I am currently not
> subscribed to this list, thanks)

Answering by both posting and mailing as requested.


Alex





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