My apologies for any redundancies or oversights for the previous posts on my part.... Bill

Hi, Luker; The related MSDN help topic for the similar compiler error I receive for the example at http://msdn.microsoft.com/en-us/library/s9zta243.aspxm, is: "A derived class cannot access protected members of its base class through an instance of the base class. An instance of the base class declared in the derived class might, at run time, be an instance of another type that is derived from the same base but is not otherwise related to the derived class. Because protected members can be accessed only by derived types, any attempts to access protected members that might not be valid at run time are marked by the compiler as not valid." If I'm following this explanation correctly, methods or member functions declared as protected can only be accessed by an immediate descendant of the base class. In the example above, since SecondDerived does not inherit its structure and behavior from FirstDerived, FirstDerived.DoSomething() cannot be called as the language is enforcing the scope and access of the protected method DoSomething(). Even if AbstracstBase.DoSomething() wasn't declared as abstract, the restricted access of the protected qualifier takes precedence. Moreover, I don't think using the internal qualifier would help, as the compiler treats this as an error, in which the derived class, FirstDerived, was trying to change the access on a method that was inherited and declared as protected in the AbstractBase class. The internal keyword, in conjunction with a correctly defined assembly attribute, can only allow the runtime to access internal methods between friend assemblies. This approach for the friend qualifier seems specific to .NET, and unfortunately, is not the same as a friend function in C++. Is it possible to provide an additional method in FirstDerived that would correctly expose and allow a call to FirstDerived.DoSomething() on behalf of the FirstDerived's consumer, or, could having the common polymorphic behavior of DoSomething() be expressed and implemented using an Interface instead? I hope this was of help. If I missed something in your question, or incorrectly stated anything with regards to the use and application of the protected and internal keywords, please let me know. Best Regards... Bill

Greetings: Although you'll end up getting all of the Python documentation, including the language reference and C API, the tutorials over at Python's official site, python.org are still some of the best around: http://docs.python.org/download.html[^] For practical applications and uses for Python, Mark Pilgrim's Dive Into Python is also a tremendous resource: http://diveintopython.org/#download[^] I hope this was of help....

Greetings: If you're an experienced programmer, Mark Pilgrim's Dive Into Python is an excellent introduction to the language. The printed edition is from APress, and can be easily found on-line and through book retailers. However, since the book was written and released under the GNU Free Documentation License, the book in its entirety is available in a variety of electronic formats, including PDF and HTML at http://diveintopython.org/[^]. If you have very little practical programming experience in other languages, Alan Gaud's Learn to Program Using Python: A Tutorial for Hobbyists, Self-Starters, and All Who Want to Learn the Art of Computer Programming from Addison-Wesley may be a good place to start. The author's web site, along with some of the material covered in his book, is available on-line at http://www.freenetpages.co.uk/hp/alan.gauld/[^]. I hope this was of help...