[Python-Dev] any support for a methodcaller HOF?

Alex Martelli aleaxit at gmail.com
Thu Feb 2 23:43:51 CET 2006

I was recently reviewing a lot of the Python 2.4 code I have written,
and I've noticed one thing: thanks to the attrgetter and itemgetter
functions in module operator, I've been using (or been tempted to use)
far fewer lambdas, particularly but not exclusively in key= arguments
to sort and sorted.  Most of those "lambda temptations" will be
removed by PEP 309 (functional.partial), and most remaining ones are
of the form:
    lambda x: x.amethod(zip, zop)

So I was thinking -- wouldn't it be nice to have (possibly in module
functional, like partial; possibly in module operator, like itemgetter
and attrgetter -- I'm partial to functional;-) a methodcaller entry
akin to (...possibly with a better name...):

def methodcaller(methodname, *a, **k):
    def caller(self):
        getattr(self, methodname)(*a, **k)
    caller.__name__ = methodname
    return caller

...?  This would allow removal of even more lambdas.

I'll be glad to write a PEP, but I first want to check whether the
Python-Dev crowd would just blast it out of the waters, in which case
I may save writing it...


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