Methods Java to Python help?

[Kenster102.5]

I have recently gotten started into Python, and am still very new at it, but I already have programing knowledge in Java and Turing.
My question is I have this Java program using Instance and Constructor methods, and am trying to re-write it in Python, but I really can't figure out what I am doing wrong.

Java Code:

Java:

import java.awt.*; public class Fraction {   //Instance Methods learned October 14.   //Creating Objects learned October 7.   public static void main(String[]args)   {     Fraction f = new Fraction();      f.num = 2;     f.den = 3;     //     f's size.     double s = f.size();         System.out.println(f.num + f.den);     System.out.println(s);       }     class Fraction   {     int num;     int den;         public Fraction larger (Fraction other)     {       if(this.size() >= other.size())         return this;       else         return other;     }     public double size()     {       return Math.abs((double)num/den);     }   } }

Python Code:

Python:

import math def MainFraction():     f = Fraction()     f.num = 2     f.den = 3     s = f.size()     print (f.num + f.den)     println (s) class Fraction:     def __init__(self):         num         den     def size():         return math.fabs(num/den)

So what must I do differently?
Thanks
Ken

[wtd]

It's worth noting that nowhere do you set up the num and den instance variables.

[Kenster102.5]

wtd @ Mon Nov 02, 2009 5:40 pm wrote:

It's worth noting that nowhere do you set up the num and den instance variables.

Ah, but sir they are stated as instance fields for the class Fraction.

[wtd]

code:

class Foo(object):     def __init__(self, a):         self.a = a b = Foo(42) print b.a

[Kenster102.5]

wtd @ Tue Nov 03, 2009 11:48 am wrote:

code:

class Foo(object):     def __init__(self, a):         self.a = a b = Foo(42) print b.a

Okay? Do I always have to do self.a = a or self.num = num for instance methods in Python, I can't just do num = num or num?

My second question:

pytho:

import math class MainFraction():     f = Fraction(2,3)     print (f.num)     print (f.den)     s = Size()     print (s) class Fraction(object):     def __init__(self,num,den):        self.num = num        self.den = den class Size(num,den):       return math.fabs(num/den)

So what do I need to do for the size method to work with the main method? Since it says that the return is outside of the method, also does Python cast automatically?
Ken

[wtd]

Have you read any Python tutorials?

[[Gandalf]]

Indeed, it seems like you're a Java coder who just picked up the Python library documentation and started piecing together code. I could be wrong.

Anyway, you'll definitely want to look into a step-by-step guide on OOP in Python.

Also, Python does not "cast automatically", take for instance:

code:

foo = 5 + "2"

Is foo a string or an integer? Is it neither?

[Kenster102.5]

[quote="[Gandalf] @ Wed Nov 04, 2009 10:42 pm"]Indeed, it seems like you're a Java coder who just picked up the Python library documentation and started piecing together code. I could be wrong.

Anyway, you'll definitely want to look into a step-by-step guide on OOP in Python.

Also, Python does not "cast automatically", take for instance:

code:

foo = 5 + "2"

Is foo a string or an integer? Is it neither?[/quote]

Well yes you are totally right, I am a Java Coder who just picked up Python, because it was introduced unofficially into my class cirriculum by another student in my class. So I feel that I should at least try to explore it.

So what did I do wrong with calling my Size object?

[wtd]

Is "Size" perhaps meant to be a function?

[Kenster102.5]

wtd @ Thu Nov 05, 2009 12:16 pm wrote:

Is "Size" perhaps meant to be a function?

Yes it is supposed to be a function, I just noticed that myself. Silly me. I will reply back tomorrow, since I am busy right now.

[Kenster102.5]

I am sorry for not having such a quick reply, but now what should I do that would fit this scenario with the Size method.