Re: Difference method vs attribut = function

On 2024-06-28 18:08:54 +0200, Ulrich Goebel via Python-list wrote:

a class can have methods, and it can have attributes, which can hold a
function. Both is well known, of course.
 
My question: Is there any difference?
 
The code snipped shows that both do what they should do. But __dict__
includes just the method,

The other way around: It includes only the attributes, not the methods.

while dir detects the method and the
attribute holding a function. My be that is the only difference?
 
 
class MyClass:
    def __init__(self):
        functionAttribute = None
       
    def method(self):
        print("I'm a method")
 
def function():
    print("I'm a function passed to an attribute")

Here is the other main difference: The object is not passed implicitely
to the function. You have no way to access mc here.

You can create a method on the fly with types.MethodType:

import types
mc.functionAttribute = types.MethodType(function, mc)

By the way: in my usecase I want to pass different functions to
different instances of MyClass. It is in the context of a database app
where I build Getters for database data and pass one Getter per
instance.

Or in this case, since each function is specific to one instance, you
could just use a closure to capture the object. But that might be
confusing to any future maintainers (e.g. yourself in 6 months), if the
method doesn't actually behave like a method.

        hp

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