dict view to list
castironpi at gmail.com
Sun Mar 29 09:39:10 CEST 2009
On Mar 27, 7:26 pm, Terry Reedy <tjre... at udel.edu> wrote:
> Luis Gonzalez wrote:
> > Yes, I know the python approach is to use built-ins.
> > But wouldn't it be cool if we could do mydict.values().tolist()
> > instead?
> Should we also give every collection a .toset(), .tofrozenset(),
> .totuple(), and .todict() method? This way lies the madness of
> combinatorial explosion.
> > It would be more regular and intuitive and readable from an OO point
> > of view.
> In my opinion, this is backwards. From an OO point of view, instances
> of class X should be created by the constructor for that class. That is
> where the knowledge of the intermal structure of class X instances
> The stream of object provided by
> the iterator is the common means of transferring information.
AKA the iterator protocol.
> It is part of python basic design. Functions used as functions can be
> passed as arguments to functions and used to operator on heterogeneous
> collections, as in the example above.
> Terry Jan Reedy
I guess there are two arguments for the change.
1. Flat is better than nested.
2. It interferes with the way people read text.
The order of events are: First, get the view. Then convert it to a
list. Hence, dictA.get_view( ).to_list( ).
This may call for a more fundamental change to a programming language
than Python should make; and it may have to wait for another
generation. It entails that function applications should be of the
form '( x )f' instead of 'f( x )', in a pretty general way.
I also recognize that natural language and thus human thinking does
admit of a certain depth of nesting. English, notably, has two means
of nesting, at least in the possessive case. 'The mother of
invention' and "invention's mother". Here is a predicate example too:
'The cat is on the mat' and 'On the mat is the cat', although the late
is mostly unattested-to these days.
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