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[Python-Dev] inline sort option

Guido van Rossum guido at python.org
Thu Oct 16 14:03:26 EDT 2003 
> Are you proposing something like:
> 
>     print mylist.sort(inplace=False)  # prints a new, sorted list while
>                                       # leaving the original list intact
> 
> 
> which would be implemented something like this:
> 
>     def inlinesort(alist, *args, **kwds):
>         newref = alist[:]
>         newref.sort(*args, **kwds)
>         return newref
> 
> 
> If that is what you're after, I think it is a good idea.  It avoids the
> perils of mutating methods returning self.  It is explicit and pleasing
> to write:
> 
>     for elem in mylist.sort(inplace=False):
>         . . .
> 
> It is extra nice in a list comprehension:
> 
>     peckingorder = [d.name for d in duck.sort(key=seniority,
> inplace=False)]
> 
> Instead of "inplace=False", an alternative is "inline=True".

*If* we're going to consider this, I would recommend using a different
method name rather than a keyword argument.  Arguments whose value
changes the return type present a problem for program analysis tools
like type checkers (and IMO are also easily overseen by human
readers).  And, it's easier to write l.sorted() rather than
l.sort(inline=True).

--Guido van Rossum (home page: http://www.python.org/~guido/)
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