[Python-Dev] What if replacing items in a dictionary returns the new dictionary?

[Mark Shannon]

Roy Hyunjin Han wrote:
> It would be convenient if replacing items in a dictionary returns the
> new dictionary, in a manner analogous to str.replace().  What do you
> think?
> ::
> 
>     # Current behavior
>     x = {'key1': 1}
>     x.update(key1=3) == None
>     x == {'key1': 3} # Original variable has changed
> 
>     # Possible behavior
>     x = {'key1': 1}
>     x.replace(key1=3) == {'key1': 3}
>     x == {'key1': 1} # Original variable is unchanged
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Could you please post this to python-ideas, rather than python-dev
Python-dev is about aspects of the implementation,
not significant language changes.

Mark.