How to create a class with get and set methods?

Question

I want to create a class myCalc that has a constructor, with get and set methods and uses a property. I understand the get and set methods but am having trouble with putting all of the pieces together so it performs what I want it to do. What I have so far is this:

class myCalc(object):

    def __init__(self):
            self._ =name

        def (self):
            """Get the answer doubled."""
            return self._plus

        def (self):
            """Get the answer squared."""
            return self._times

I'd like to get as far as having the program respond with properties that double and square the number in the object. Any suggestions would be helpful.

What is it that you want to get and set? Particularly set. I don't see much call for a setter here. — user2357112, Sep 03 '13 at 04:01
Duplicate of http://stackoverflow.com/questions/2627002/whats-the-pythonic-way-to-use-getters-and-setters — Kracekumar, Sep 03 '13 at 04:05

score 5 · Answer 1 · answered Sep 03 '13 at 03:39

5

A property object has getter, setter, and deleter methods You should use decorators as follows:

class C(object):
    def __init__(self):
        self._x = None

    @property
    def x(self):
        """I'm the 'x' property."""
        return self._x

    @x.setter
    def x(self, value):
        self._x = value

    @x.deleter
    def x(self):
        del self._x

If you want it readonly, just use @property and remove the two others

answered Sep 03 '13 at 03:39

Serjik

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Sorry for the delay! Appreciate the answers so far. The reason why I want a get and set method is to retrieve and set the value of a property named “name,” that reflects the object’s name. – fractal21 Sep 10 '13 at 03:11

hpaulj · Answer 2 · 2013-09-03T05:05:35.070

1

A simple object that has doubled and squared properties

class myCalc(object):
    def __init__(self, value):
        self.value = value
    def __str__(self):
        return str(self.value)
    def dbler(self):
        return self.value*2
    doubled = property(dbler)
    squared = property(lambda self: self.value**2)
    # equivalent with the decorator
    @property
    def cubed(self):
        return self.value**3

if __name__ == '__main__':
    x = myCalc(10)
    print x # 10
    print x.doubled  # 20
    print x.squared  # 100
    print x.cubed # 1000

Adapted from http://docs.python.org/2/howto/descriptor.html#properties

edited Sep 03 '13 at 05:05

answered Sep 03 '13 at 04:50

hpaulj

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If I wanted to adapt this to allow a user to change the name by using the get and set properties, would it need the raw input code to refer back to the get/set? – fractal21 Sep 10 '13 at 03:25

score 0 · Answer 3 · answered Sep 11 '13 at 09:50

class myCalc(object):

def_init_(self, value)
self.value=value

def_init_(self, name)
print "Welcome to myCalc!"

self._name=name

def get_name(self):
        return self._name

def set_name(self, new_name):
    if new_name=="":
        print "You mut enter a name."
    else:
        self._name=new_name
        print "The name has been changed."

def_str_(self)
return str(self.value)

def dbler(self):
    return self.value*2

doubled=property(dbler)
squared=property(lambda self: self.value**2)

name=property(get_name, set_name)

def talk(self):
    print "\nWelcome, this is," self.name

if name=='main': x= myCalc(5) print x print x.doubled print x.squared

mainline

calc=myMath("Calculator") calc.talk()

print "\nmyCalc's name is:", print calc.name

print "\nChanging myCalc's name." calc.name=""

calc.talk()

raw_input("\n\nPress the enter key to exit."

Here is what I am looking to do, however I keep coming across errors. I want to be able to change the object name AND number.

How to create a class with get and set methods?

3 Answers3

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