what does this mean?

[bobueland at yahoo.com]

In van Rossum's tutorial there is a paragraph in chapter 9.6 which says

"Notice that code passed to exec, eval() or evalfile() does not
consider the classname of the invoking class to be the current class;
this is similar to the effect of the global statement, the effect of
which is likewise restricted to code that is byte-compiled together.
The same restriction applies to getattr(), setattr() and delattr(), as
well as when referencing __dict__ directly."

What does this mean? Could someone give a simple example or point to a
web page explaining this.

Bob