classes and objects in python

classes and objects

1. Classes and Objects and Concepts

• Class: the abstraction of common things, is a description of a class with common things, is a collection with the same attributes and methods
• Object: An instance of a class, an embodiment of a common thing, each individual in this type of thing

2. Summary:

A class is a template for an object, and an object is an instance of a class

3. Syntax for creating a class

class Math: #Class                    names are usually capitalized 
    a = 4                      #Attributes
    b = 5

    def add(self):
        c = self.a + self.b
        return c

Notice:

1. Class names are generally capitalized, such as class User, where class is a keyword
2. A class contains properties (variables) and methods (functions)
3. The class function comes with the self keyword, no less! Self points to the object itself, which is a reference to an instance of the class
4. If you want to call property (self. property name), method (self. method name) in a class or function

instantiate

1. Instance name = class name(), such as the Math class instantiation above; math_1 = Math()

2. Example

class Friend:

    def __init__(self, height, age, money):
        self.height = height
        self.age = age
        self.money = money

    def can_Cook(self, can = True):
         if can == True:
             return  " Can cook! " 
        else :
             return  " Ca n't cook! "

Peter = Friend( " 178 " , 27, " 2000000 " )
 print ( " Peter is {0} years old, is {1}cm tall, has a deposit of {2} yuan, and {3} " .format(Peter.age, Peter. height, Peter.money, Peter.can_Cook()))

operation result:

Peter is 27 years old, 178cm tall, has a deposit of 2,000,000, and can cook!