How much introspection is implementation dependent?

[James Stroud]

George Sakkis wrote:
> On Feb 2, 6:56 pm, James Stroud <jstr... at mbi.ucla.edu> wrote:
> 
>> Hello,
>>
>> I wanted to automagically generate an instance of a class from a
>> dictionary--which might be generated from yaml or json. I came up with this:
>>
>> (snip)
>>
>> ==
>>
>> #! /usr/bin/env python
>>
>> # automagical constructor
>> def construct(cls, adict):
>>    dflts = cls.__init__.im_func.func_defaults
>>    vnames = cls.__init__.im_func.func_code.co_varnames
>>
>>    argnames = vnames[1:-len(dflts)]
>>    argvals = [adict.pop(n) for n in argnames]
>>
>>    return cls(*argvals, **adict)
>>
>> def test():
>>
>>    class C(object):
>>      def __init__(self, arg1, arg2, kwa3=3):
>>        self.argsum = arg1 + arg2
>>        self.kwsum = kwa3
>>      def __str__(self):
>>        return "%s & %s" % (self.argsum, self.kwsum)
>>
>>    # now a dict for autmagical generation
>>    adict = {'arg1':1, 'arg2':2, 'kwa3':42}
>>
>>    print '======== test 1 ========'
>>    print adict
>>    print construct(C, adict)
>>
>>    adict = {'arg1':1, 'arg2':2}
>>    print
>>    print '======== test 2 ========'
>>    print adict
>>    print construct(C, adict)
>>
>> if __name__ == "__main__":
>>    test()
> 
> What's the point of this ? You can call C simply by C(**adict). Am I
> missing something ?
> 
> George
> 

Maybe there is something wrong with my python.

py> class C:
...   def __init__(a, b, c=4):
...     print a,b,c
...
py> C(**{'a':10, 'b':5, 'c':4})
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
TypeError: __init__() got multiple values for keyword argument 'a'


James