[Tutor] How to learn messages frim help()?

[=?GB2312?B?uqvP3Ma9?=]

On 7/10/06, Alan Gauld <alan.gauld at freenet.co.uk> wrote:
> > Hi,all.For example,I want learn build-in function TYPE,do help(type)
> > and get message as following:
> >
> > Help on class type in module __builtin__:
> >
> > class type(object)
> > |  type(object) -> the object's type
> > |  type(name, bases, dict) -> a new type
> > |
> > |  Methods defined here:
> > |
> > |  __call__(...)
> > |      x.__call__(...) <==> x(...)
> > |
> > |  __cmp__(...)
> > |      x.__cmp__(y) <==> cmp(x,y)
>
> > Have TYPE defined these methods?
> > What relation with __call__,__cam__ etc?
>
> I'm not sure what you are asking but yes, the help screen
> is telling you that the type class implements these
> methods and subtypes can overrride them.
>
> Thus the type int is callable so we can do things like:
>
> print int('45')
>
> Similarly we can compare items of a given type
> because the cmp method is implemented, so
> we can do
>
> print type(5) == type(42)
>
> Does that answer your question?
>
> Alan Gauld
> Author of the Learn to Program web site
> http://www.freenetpages.co.uk/hp/alan.gauld
>
>
Thank you Alan.That exactelly my question!!