How to refer to the function object itself in the function per se?

[Sullivan WxPyQtKinter]

When debugging using 'print' statement, I usually want to print some
important values together with the function name as the context of the
values printed out. So my hope is that I could get the name of the
function.

Since every function object actually has a private __name__ attribute
that gives its name, but when I

print __name__

in a function, it usually print the public module-level __name__
attribute, ie, 'main', rather than the function level __name__. So how
could I refer to the function object per se, in the body of the
function itself?

[Duncan Booth]

Re: How to refer to the function object itself in the function per se?

Sullivan WxPyQtKinter wrote:[color=blue]
> So how
> could I refer to the function object per se, in the body of the
> function itself?
>
>[/color]
I don't believe you can easily get at the function object, but you can get
at the code object which also has a name (which will be the same as the
function's name unless you've been doing strange things):
[color=blue][color=green][color=darkred]
>>> import inspect
>>> def f():[/color][/color][/color]
print inspect.current frame().f_code. co_name

[color=blue][color=green][color=darkred]
>>> f()[/color][/color][/color]
f

For convenience you might want to put this inside a function:
[color=blue][color=green][color=darkred]
>>> def myname():[/color][/color][/color]
f = inspect.current frame().f_back
return f.f_code.co_nam e
[color=blue][color=green][color=darkred]
>>> def f():[/color][/color][/color]
print myname()

[color=blue][color=green][color=darkred]
>>> f()[/color][/color][/color]
f

[Sullivan WxPyQtKinter]

Re: How to refer to the function object itself in the function per se?

I have Google the whole thing and find another way for alternative
implementation of getting the function's name. But all they returns are
just strings. If I would like to refer to the function object in order
to call it recursively, what shall I do then?

[Duncan Booth]

Re: How to refer to the function object itself in the function per se?

Sullivan WxPyQtKinter wrote:
[color=blue]
> I have Google the whole thing and find another way for alternative
> implementation of getting the function's name. But all they returns are
> just strings. If I would like to refer to the function object in order
> to call it recursively, what shall I do then?
>[/color]

a) Learn to quote properly.

b) Use the function's name.

[Kay Schluehr]

Re: How to refer to the function object itself in the function per se?

Sullivan WxPyQtKinter wrote:
[color=blue]
> So how
> could I refer to the function object per se, in the body of the
> function itself?[/color]

Just use the name.

def f():
print f.__name__
[color=blue][color=green][color=darkred]
>>> f()[/color][/color][/color]
f

[Sullivan WxPyQtKinter]

Re: How to refer to the function object itself in the function per se?

I am sorry but you misunderstood my idea.
What I want is a generalized method to print out the function name, or
refer to the name of a function. If I use f.__name__, I think I should
just use print "f" to save my keyboard. What I expect is using a
method, or attribute, or another function to get the name of a
function.
Kay Schluehr 写道：
[color=blue]
> Sullivan WxPyQtKinter wrote:
>[color=green]
> > So how
> > could I refer to the function object per se, in the body of the
> > function itself?[/color]
>
> Just use the name.
>
> def f():
> print f.__name__
> [color=green][color=darkred]
> >>> f()[/color][/color]
> f[/color]

[James Stroud]

Re: How to refer to the function object itself in the function perse?

Sullivan WxPyQtKinter wrote:
If I would like to refer to the function object in order[color=blue]
> to call it recursively, what shall I do then?[/color]

I think the question is too simple. You can just refer to the function
by its name. Here is an example:


py> def f(start, end):
.... if start >= end:
.... print 'start is end:', start
.... else:
.... print "start increasing to:", start
.... f(start+1, end)
.... print 'leaving f() where start is', start
....
py> f(1,10)
start increasing to: 1
start increasing to: 2
start increasing to: 3
start increasing to: 4
start increasing to: 5
start increasing to: 6
start increasing to: 7
start increasing to: 8
start increasing to: 9
start is end: 10
leaving f() where start is 10
leaving f() where start is 9
leaving f() where start is 8
leaving f() where start is 7
leaving f() where start is 6
leaving f() where start is 5
leaving f() where start is 4
leaving f() where start is 3
leaving f() where start is 2
leaving f() where start is 1

James

--
James Stroud
UCLA-DOE Institute for Genomics and Proteomics
Box 951570
Los Angeles, CA 90095

http://www.jamesstroud.com/

[James Stroud]

Re: How to refer to the function object itself in the function perse?

Sullivan WxPyQtKinter wrote:[color=blue]
> I am sorry but you misunderstood my idea.
> What I want is a generalized method to print out the function name, or
> refer to the name of a function. If I use f.__name__, I think I should
> just use print "f" to save my keyboard. What I expect is using a
> method, or attribute, or another function to get the name of a
> function.[/color]

Not exactly:

py> def f():
.... print 'this is function f'
....
py> g = f
py>
py> print g.__name__
f

You might be confusing the idea of a name with the idea of a reference.
It really doesn't matter what you name a function. As long as you have a
reference to a function, or 'callable', you can call it.

py> g()
this is function f

You can even create a reference to a function and call that reference in
the function after the function is defined:

py> def f(start, end):
.... if start >= end:
.... print 'start is end', start
.... else:
.... g(start+1, end)
.... print 'leaving function where start is', start
....
py> g = f
py> f(1,5)
start is end 5
leaving function where start is 5
leaving function where start is 4
leaving function where start is 3
leaving function where start is 2
leaving function where start is 1

But beware re-binding a name in such circumstances:

py> def g(*args):
.... print 'g rebound! args are', args
....
py> f(1,5)
g rebound! args are (2, 5)
leaving function where start is 1

I hope this clears things up.

James

--
James Stroud
UCLA-DOE Institute for Genomics and Proteomics
Box 951570
Los Angeles, CA 90095

http://www.jamesstroud.com/

[Kay Schluehr]

Re: How to refer to the function object itself in the function per se?


Sullivan WxPyQtKinter wrote:[color=blue]
> I am sorry but you misunderstood my idea.
> What I want is a generalized method to print out the function name, or
> refer to the name of a function. If I use f.__name__, I think I should
> just use print "f" to save my keyboard. What I expect is using a
> method, or attribute, or another function to get the name of a
> function.[/color]

Sorry, if the example was misleading. Here is a better one:

def f(g):
print g.__name__
[color=blue][color=green][color=darkred]
>>> f(f)[/color][/color][/color]
f

The __name__ attribute of f is constant and it doesn't matter whether
you pass f around or create aliases:
[color=blue][color=green][color=darkred]
>>> x = f
>>> x.__name__[/color][/color][/color]
f

x refers still to the function object f. Therefore the __name__
attribute does not return "x" but "f". You will always print the right
function name not the name of the local variable.

Kay