argument checking before getattr

[Chris Liechti]

Benjamin Tai <bt98 at doc.ic.ac.uk> wrote in 
news:3C406C31.D5ED90F6 at doc.ic.ac.uk:
[snip]
> Instead of doing (hiding) argument checking in the interface, now I am
> hoping to do some type checking in Python. The following shows what I am
> trying to achieve:
> 
> class foo:
>       def foo_fun(self,args):
>             # do some checking on "args"
>             return getattr(self._base,"foo_fun")
> 
> Instead of return the correct argument, it only returns a trace of the
> following trace:
> <built-in method foo_fun of foo object at 0x80ef820>
> It doesn't work out. Why?

because getattr gives you the function object in this case.
use apply to call the function. or write self._base.foo_fun(args)

-- 
Chris <cliechti at gmx.net>