Python - OOPS Basics - Day 25(4 days later)

Class:template for creating objects.All objects created using the same class will have the same charecteristics Objects:an instance of a class Instantiate:Create a Instance of a class Method:a funtion defined in a class Attribute:a variable bound to a instance of a class

  
#everything is objects in python
#take away : class and objects

# a = 1
# b = 3
# print (a + b)
# print (a.__add__(b))
#so + is same as __add__ ,if u ctrl right click it will goto the same definition

class kettle (object):

    power_source = 'fuel'

    def __init__(self,make,price):
        self.make = make
        self.price = price
        self.on = False

    def switch_on(self):
        self.on = True

kenwoodobj = kettle('kenwood',25)
hamilton = kettle('hamilton',30)

print(kenwoodobj.make)
print(hamilton.make)
print(hamilton.price)
hamilton.make = 'Hamiltoon'
print(hamilton.make)
print(kenwoodobj)

print ('{}={},{}={}'.format(kenwoodobj.make,kenwoodobj.price,hamilton.make,hamilton.price))
kenwoodobj1 = kenwoodobj
print(id(kenwoodobj1))
print(id(kenwoodobj))
print(id(hamilton))
print(id(hamilton.make))

#we can call the object by
#classname.objectname(instancename)
#or
#instancename.objectname()
kettle.switch_on(hamilton)
print(hamilton.make)
print(hamilton.on)
hamilton.on = False
print(hamilton.on)
hamilton.switch_on()
print(hamilton.on)

#this is called as instance variable,variable is only for this instance,not for the entire instances of the
#class
kenwoodobj.power = 1.5
print(kenwoodobj.power)
#if we try accessing the same variable for different instance,it will throw error
# print(hamilton.power)

print (kettle.power_source)
print (kenwoodobj.power_source)
print (hamilton.power_source)

print(kettle.__dict__)
print(kenwoodobj.__dict__)
print(hamilton.__dict__)

print ('*' * 80)

# kettle.power_source = 'atomic'

print (kettle.power_source)
print (kenwoodobj.power_source)
print (hamilton.power_source)

print(kettle.__dict__)
print(kenwoodobj.__dict__)
print(hamilton.__dict__)

print ('/' * 80)

#if we assign the value for the calss attribute instance,it becomes instance vriable and remains
#unaffected for the class and other instances
kenwoodobj.power_source = 'gas'

print (kettle.power_source)
print (kenwoodobj.power_source)
print (hamilton.power_source)

print(kettle.__dict__)
print(kenwoodobj.__dict__)
print(hamilton.__dict__)

print ('*' * 80)
hamilton.power_source = 'fossil fuel'

print (kettle.power_source)
print (kenwoodobj.power_source)
print (hamilton.power_source)

print(kettle.__dict__)
print(kenwoodobj.__dict__)
print(hamilton.__dict__)

hamilton.power_source = 'fuel'

print (kettle.power_source)
print (kenwoodobj.power_source)
print (hamilton.power_source)

print(kettle.__dict__)
print(kenwoodobj.__dict__)
print(hamilton.__dict__)

print ('@' * 80)

kettle.power_source = 'fuel'

print (kettle.power_source)
print (kenwoodobj.power_source)
print (hamilton.power_source)

print(kettle.__dict__)
print(kenwoodobj.__dict__)
print(hamilton.__dict__)
 

this will explain how a basic program document has to be written

  
#this will explain you how to document a program(DocString)
class song:
    """
    class to represent a song

    Attributes:
        title():The tile of the song
        artist(Artist):An artist object representing the songs creator
        duration (int):The duration of the song in seconds.May be Zero
    """
    def __int__(self,title,artist,duration=0):
        """song init method
        Args:
            title(str):Intialises the 'title' attribute
            artist(Artist):An artist object representing the songs creator
            duration (optional int):initialise value to 'duration' attribute
                    will be defaulted to zero if not specified.


        """
        self.title = title
        self.artist = artist
        self.duration = duration