Least used builtins?

[John Roth]

Reducing the number of builtins doesn't seem like the
right direction. I'd prefer to see something in the
official documentation that tries to bring some
conceptual order to the builtins. While my mind *likes*
to read down a list of dispariate things and try to bring
some order out of the mess, I know that others are
put off by the task.

For example:

Functional Programming:
    map()
    reduce()
    filter()
    itertools module
    zip()
Mathematics and similar:
    abs()
    complex()
    complex math module
    divmod()
    float()
    int()
    long()
    max()
    min()
    pow()
    round()
Reflection and meta-programming
    apply() *depreciated*
    callable()
    compile()
    delattr()
    eval()
    execfile()
    getattr()
    hasattr()
    input()
    isinstance()
    issubclass()
    setattr()
    vars()

Maybe with a one line (no more!) explanation of what the function or
module does.

John Roth