function pointers

[Fredrik Lundh]

Brandon J. Van Every wrote:
> I get the feeling that Python doesn't have anything resembling a function
> pointer?  i.e. no way to call a specific function according to the value a
> variable is set to?  In fact, I get the feeling it doesn't have pointers of
> any sort at all?

everything is an object, and all variables are references to
objects.

the following statement creates an integer object, and binds
the name "bacon" to it:

    bacon = 10

functions are no different from other objects:

    def spam(egg):
        print egg

creates a function object, and binds the name "spam" to it:

    >>> spam
    <function spam at 866e10>

you can treat function objects as any other object (pass it to
a function, return it from a function, append it to a list, etc).

to call it, just give the arguments in parentheses as usual:

    def do(callback):
        return callback("hello")

    >>> do(spam)
    hello
    >>> do(len)
    5
    >>> do(list)
    ['h', 'e', 'l', 'l', 'o']

Cheers /F