Re: OO in Python? ^^

Brian Beck wrote:
>>
>> class D1(Base):
>> def foo(self):
>> print "D1"
>>
>> class D2(Base):
>> def foo(self):
>> print "D2"
>> obj = Base() # I want a base class reference which is polymorphic
>> if (<need D1>):
>> obj = D1()
>> else:
>> obj = D2()
>
> I have no idea what you're trying to do here and how it relates to
> polymorphism.
>

He's translating C++ code directly to Python. obj = Base() creates a
variable of type Base(), to which you can assign different object types (D
(), D2()) which implement the Base interface (are derived from Base).
Err... At least I think it's what this code is supposed to mean...

In C++ you'd do:

Base *baseob;

if( <i want d1> ) {
baseob = (Base*)new D1();
} else {
baseob = (Base*)new D2();
}

baseob->foo();

(should, if foo is declared virtual in Base, produce "d1" for D1, and "d2"
for D2)

At least IIRC, it's been quite some time since I programmed C++... ;-)
*shudder*

--- Heiko.
.

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