On 15/05/2015 23:44, Marko Rauhamaa wrote:
BartC <b...@freeuk.com>:
What /is/ a method lookup? Is it when you have this:
A.B()
and need to find whether the expression A (or its class or type) has a
name B associated with it? (And it then needs to check whether B is
something that can be called.)
If so, does that have to be done using Python's Dict mechanism? (Ie.
searching for a key 'B' by name and seeing if the object associated
with it is a method. That does not sound efficient.)
That is a general feature among high-level programming languages. In
Python, it is even more complicated:
* first the object's dict is looked up for the method name
* if the method is not found (it usually isn't), the dict of the
object's class is consulted
* if the method is found (it usually is), a function object is
instantiated that delegates to the class's method and embeds a "self"
reference to the object to the call
IOW, two dict lookups plus an object construction for each method call.
Marko
As a picture paints a thousand words is anybody aware of a site or sites
that show this diagramatically, as I think I and possibly others would
find it far easier to grasp.
--
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.
Mark Lawrence
--
https://mail.python.org/mailman/listinfo/python-list
