On Jun 18, 3:41 pm, [EMAIL PROTECTED] wrote: > On Jun 18, 3:13 pm, Cédric Lucantis <[EMAIL PROTECTED]> wrote: > > > > > Hi, > > > Le Wednesday 18 June 2008 20:19:12 [EMAIL PROTECTED], vous avez écrit : > > > > Hi. I am looking for a way to check if some given set of (*args, > > > **kwds) conforms to the argument specification of a given function, > > > without calling that function. > > > > For example, given the function foo: > > > def foo(a, b, c): pass > > > > and some tuple args and some dict kwds, is there a way to tell if i > > > _could_ call foo(*args, **kwds) without getting an exception for those > > > arguments? I am hoping there is a way to do this without actually > > > writing out the argument logic python uses. > > > Each function object is associated to a code object which you can get with > > foo.func_code. Two of this object's attributes will help you: co_argcount > > and > > co_varnames. The first is the number of arguments of the function, and the > > second a list of all the local variables names, including the arguments > > (which are always the first items of the list). When some arguments have > > default values, they are stored in foo.func_defaults (and these arguments > > are > > always after non-default args in the co_argnames list). > > > Finally, it seems that some flags are set in code.co_flags if the function > > accepts varargs like *args, **kwargs, but I don't know where these are > > defined. > > > Note that I never found any doc about that and merely guessed it by playing > > with func objects, so consider all this possibly wrong or subject to change. > > > -- > > Cédric Lucantis > > I am aware of these attributes, although you can get them all in a > more organized form using the getfullargspec function in the inspect > module from the standard library. > > The problem is that using these attributes, I would essentially have > to re-write the logic python uses when calling a function with a given > set of arguments. I was hoping there is a way to get at that logic > without rewriting it.
Sure; copy it from someone that has already done it ;-) http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/551779 HTH, George -- http://mail.python.org/mailman/listinfo/python-list
