super

how to use 'super' ?

Hi, I was wondering if anyone could explain to me the difference between doing class Child(SomeBaseClass): def __init__(self): super(Child, self).__init__() and this class Child(SomeBaseClass): def __init__(self): SomeBaseClass.__init__(self) I've seen 'super' being used quite alot in classes with only sing...

super() function in JAVA

Button class: class SubmitButton extends JButton implements ActionListener { public SubmitButton(String title){ super(title); .... Where I declare it: SubmitButton submit = new SubmitButton("Submit"); submit.setBounds(530+150, 200, 100, 25); How does super(title) set the String title to the title of the button? ...

"MetaClass", "__new__", "cls" and "super" - can someone explain the mechanism exactly

I have read posts like these: What is a metaclass in Python? What are your (concrete) use-cases for metaclasses in Python? Python's Super is nifty, but you can't use it but somehow I got confused, many confusions like when and why i would have to do something like this #refer link1 return super(MyType, cls).__new__(cls, name, bas...

using constructor from the super class

Hello, Java does not allow multiple inheritance, meaning that a class cannot inherit from two classes, which does not have anything in common, meaning that they are not on the same inheritance path. However, a class can inherit from more classes, if these classes are super classes of the direct super class of the class. But the class in...

python super() raises TypeError ! Why ?

The following code raises a TypeError : >>> class X: ... def a(self): ... print "a" ... >>> class Y(X): ... def a(self): ... super(Y,self).a() ... print "b" ... >>> c = Y() >>> c.a() Traceback (most recent call last): File "", line 1, in File "", line 3, in a TypeError: super() argument 1 must be type, not classobj...

Understanding Python super()

Trying to understand super(). From the looks of it, both child classes can be created just fine. Im curious as to what difference there actually is in this code: class Base(object): def __init__(self): print "Base created" class ChildA(Base): def __init__(self): Base.__init__(self) class ChildB(Base): def _...

How does Python's "super" do the right thing?

I'm running Python 2.5, so this question may not apply to Python 3. When you make a diamond class hierarchy using multiple inheritance and create an object of the derived-most class, Python does the Right Thing (TM). It calls the constructor for the derived-most class, then its parent classes as listed from left to right, then the grandp...

C++ Explicit Superclass Constructor Problem While Using Header Files

Hello, I seem to be having a very frustrating time with an inherited class calling an explicit superclass constructor. I just can't seem to get the syntax right! All the examples I have seen on the matter so far do not separate out the header and in-line class definition (using {}'s) from forward-declarations with a header file, so I'...

return generic type from generic function

we have a function more or less like the following. however we currently return List which in function bla() would return List<Bar> at runtime. I'm looking for a way to make both List<Interface> = toubleFuction(foo, bar.getCLass());; and List<Bar> = toubleFuction(foo, bar.getCLass());; possible. basicaly i want it to return List ...

compilers for languages from 1950's and 1960's

i am trying to find the best compilers (if they are actually available) for the following languages: ALGOL 60 TRAC TELCOMP Superplan BACAIC i don't know if any of these are still around, but it would be very helpful to get any feedback on where i could locate these. ...

Basic examples of single-inheritence super() in Python

Let's say I have the following classes set up: class Foo: def __init__(self, frob, frotz): self.frobnicate = frob self.frotz = frotz class Bar: def __init__(self, frob, frizzle): self.frobnicate = frob self.frotz = 34 self.frazzle = frizzle How can I (if I can at all) use sup...

Is it a good idea to use super() in Python?

Or should I just explicitly reference the superclasses whose methods I want to call? It seems brittle to repeat the names of super classes when referencing their constructors, but this page http://fuhm.net/super-harmful/ makes some good arguments against using super(). ...

Python methods: default parameter values are evaluated ONCE

Hello. I've found a strange issue with subclassing and dictionary updates in New-Style Classes: Python 2.6.2 (r262:71605, Apr 14 2009, 22:40:02) [MSC v.1500 32 bit (Intel)] on win32 >>> class a(object): ... def __init__(self, props={}): ... self.props = props ... >>> class b(a): ... def __init__(self, val = None): .....

Using Super in an Objective C Category?

I'd like to override a method in an Objective C class that I don't have the source to. I've looked into it, and it appears that Categories should allow me to do this, but I'd like to use the result of the old method in my new method, using super to get the old methods result. Whenever I try this though, my method gets called, but "supe...

Extending Generic Abstract Class & Correct Use of Super

public abstract class AbstractTool<AT extends AbstractThing> { protected ArrayList<AT> ledger; public AbstractTool() { ledger = new ArrayList<AT>(); } public AT getToolAt(int i) { return ledger.get(i); } // More code Which operates on Ledger ... } public class Tool<AT extends AbstractThing> extends A...

Private methods using Categories in Objective-C: calling super from a subclass.

Hello folks, I was reading how to implement private methods in Objective-C (Best way to define private methods for a class in Objective-C) and a question popped up in my mind: How do you manage to implement protected methods, i.e. private methods that are visible to subclasses? Suppose I have a MySuperClass with a Category containing ...

accept supertype of generic parameter on single object?

is it possible somehow to accept only super types of the generic Type of a class? what im looking for is something like: class <T extends Object> MyClass { public <TS super T> void myMethod(TS someObjectSuperToTheClass) { //do stuff } } i don't really need it anymore (and its probably not all that usefull to begin with) but I'm ...

Using super with a class method

I'm trying to learn myself the super() function in Python. I though I got a grasp of it untill I came over this example (2.6) and found myself stuck. http://www.cafepy.com/article/python_attributes_and_methods/python_attributes_and_methods.html#super-with-classmethod-example Traceback (most recent call last): File "<stdin>", line 1,...

Using super() in nested classes.

Imagine this: class A(object): class B(object): def __init__(self): super(B, self).__init__() This creates an error: NameError: global name B is not defined. I've tried A.B, but then it says that A is not defined. Update: I've found the problem. I've had a class like this: class A(object): class B(o...

Calling super on a method defined by define_method

I have created a Model class where I define methods based on a method (attribute) called in User (which inherits from Model). The problem is that I cannot override the method defined by define_method, and call super to pass to the defined method. I guess this is because the defined method is added to User itself, and not to the Model, so...