Function attributes
in [Python]
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From: Muhammad Alkarouri on 10 Feb 2010 08:59 Hi everyone, What is the simplest way to access the attributes of a function from inside it, other than using its explicit name? In a function like f below: def f(*args): f.args = args print args is there any other way? I am guessing the next question will be: should I really care? It just feels like there should be a way, but I am not able to verbalise a valid one at the moment, sorry. Regards, Muhammad Alkarouri
From: Steven D'Aprano on 10 Feb 2010 09:36 On Wed, 10 Feb 2010 05:59:41 -0800, Muhammad Alkarouri wrote: > Hi everyone, > > What is the simplest way to access the attributes of a function from > inside it, other than using its explicit name? In a function like f > below: > > def f(*args): > f.args = args > print args > > is there any other way? Not built-in. > I am guessing the next question will be: should I really care? It just > feels like there should be a way, but I am not able to verbalise a valid > one at the moment, sorry. I completely agree with you. It is a wart that functions are only able to refer to themselves by name, because if the name changes, things break. Consider: old_f = f # save the old version of the function def f(x): return old_f(x+1) # make a new function and call it f This won't work correctly, because old_f still tries to refer to itself under the name "f", and things break very quickly. -- Steven
From: Krister Svanlund on 10 Feb 2010 09:46 On Wed, Feb 10, 2010 at 2:59 PM, Muhammad Alkarouri <malkarouri(a)gmail.com> wrote: > Hi everyone, > > What is the simplest way to access the attributes of a function from > inside it, other than using its explicit name? > In a function like f below: > > def f(*args): > f.args = args > print args > > is there any other way? > I am guessing the next question will be: should I really care? It just > feels like there should be a way, but I am not able to verbalise a > valid one at the moment, sorry. > > Regards, > > Muhammad Alkarouri > -- > http://mail.python.org/mailman/listinfo/python-list > This sounds like something you shouldn't be doing. You should probably use a class instead. (Sending again to get it on the list >_<)
From: John Posner on 10 Feb 2010 10:08 On 2/10/2010 9:36 AM, Steven D'Aprano wrote: > On Wed, 10 Feb 2010 05:59:41 -0800, Muhammad Alkarouri wrote: > >> Hi everyone, >> >> What is the simplest way to access the attributes of a function from >> inside it, other than using its explicit name? In a function like f >> below: >> >> def f(*args): >> f.args = args >> print args >> >> is there any other way? > > Not built-in. > > >> I am guessing the next question will be: should I really care? It just >> feels like there should be a way, but I am not able to verbalise a valid >> one at the moment, sorry. > > I completely agree with you. It is a wart that functions are only able to > refer to themselves by name, because if the name changes, things break. > Consider: > > old_f = f # save the old version of the function > > def f(x): > return old_f(x+1) # make a new function and call it f > > This won't work correctly, because old_f still tries to refer to itself > under the name "f", and things break very quickly. They didn't break immediately for me -- what am I missing?: #------------------- def f(): return "old func" g = f print "name attr of f:", f.__name__ print "name attr of g:", g.__name__ def f(): return "new func" print "name attr of f:", f.__name__ print "name attr of g:", g.__name__ print "*** calling function currently named f:" print f() print "*** calling function currently named g:" print g() #------------------- program output (Python 2.6.4): name attr of f: f name attr of g: f name attr of f: f name attr of g: f *** calling function currently named f: new func *** calling function currently named g: old func -John
From: Bruno Desthuilliers on 10 Feb 2010 10:24
John Posner a écrit : > On 2/10/2010 9:36 AM, Steven D'Aprano wrote: >> On Wed, 10 Feb 2010 05:59:41 -0800, Muhammad Alkarouri wrote: >> (snip) >>> def f(*args): >>> f.args = args >>> print args >>> (snip) >> I completely agree with you. It is a wart that functions are only able to >> refer to themselves by name, because if the name changes, things break. >> Consider: >> >> old_f = f # save the old version of the function >> >> def f(x): >> return old_f(x+1) # make a new function and call it f >> >> This won't work correctly, because old_f still tries to refer to itself >> under the name "f", and things break very quickly. > > They didn't break immediately for me -- what am I missing?: The fact that in the OP's snippet, code inside f's body refers to f by its name. |