[Python-Dev] _length_cue()

[Bengt Richter]

On Fri, 10 Feb 2006 14:33:08 +0100, Armin Rigo <arigo at tunes.org> wrote:

>Hi Nick,
>
>On Fri, Feb 10, 2006 at 11:21:52PM +1000, Nick Coghlan wrote:
>> Do they really need anything more sophisticated than:
>> 
>>    def __repr__(self):
>>      return "%s(%r)" % (type(self).__name__, self._subiter)
>> 
>> (modulo changes in the format of arguments, naturally. This simple one would 
>> work for things like enumerate and reversed, though)
>
>My goal here is not primarily to help debugging, but to help playing
>around at the interactive command-line.  Python's command-line should
>not be dismissed as "useless for real programmers"; I definitely use it
>all the time to try things out.  It would be nicer if all these
>iterators I'm not familiar with would give me a hint about what they
>actually return, instead of:
>
>>>> itertools.count(17)
>count(17)                  # yes, thank you, not very helpful
>>>> enumerate("spam")
>enumerate("spam")          # with your proposed extension -- not better
>
>However, if this kind of goal is considered "not serious enough" for
>adding a private special method, then I'm fine with trying out a fishing
>approach.
>
For enhancing interactive usage, how about putting the special info and smarts in help?
Or even a specialized part of help, e.g.,

    help.explain(itertools.count(17))

or maybe

    help.explore(itertools.count(17))

leading to an interactive prompt putting handy cmdwords in a line to get
easily to type, mro, non-underscore methods, attribute name list, etc.

E.g. I often find myself typing stuff like
    [x for x in dir(obj) if not x.startswith('_')]
or
    [k for k,v in type(obj).__dict__.items() if callable(v) and not k.startswith('_')]
that I would welcome being able to do easily with a specialized help.plaindir(obj)
or help.plainmethods(obj) or help.mromethods(obj) etc.

Hm, now that I think of it, I guess I could do stuff like that in site.py, since
 
 >>> help.plaindir = lambda x: sorted([x for x in dir(x) if not x.startswith('_')])
 >>> help.plaindir(int)
 []
 >>> help.plaindir([])
 ['append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']

But some kind of standards would probably be nice for everyone if they like the general idea.
I'll leave it to someone else as to whether and where a thread re help enhancements
might be ok.

My .02USD ;-)

Regards,
Bengt Richter