Comprehensive understanding of classes, objects, methods, and attributes in python

The following editor will bring you a comprehensive understanding of the classes, objects, methods, properties in python. The editor thinks it is quite good, so I will share it with you now and give it as a reference for everyone. Let’s follow the editor and take a look.

">

Everything in Python is an object. The so-called object: I myself am an object, the computer I play with is an object, and the chair I sit on is an object. It is an object, and the puppy at home is also an object. . . .

##We describe an object by describing its color and size. Age, weight, etc. are its attributes or characteristics. It barks, wags its tail, etc. are its behaviors.

We include two aspects when describing a real object (object):

What it can do (behavior)

What it is (attribute or characteristic)

In python, the characteristics of an object are also called attributes. The behavior it has is also called a method

Conclusion: object = attribute + method

In python, objects with the same

attributes and methods are grouped into one Class (class)

For example, humans, animals, plants, etc., these are the concepts of class

Class is the template or blueprint of the object, and the class is the object. Abstraction, objects are instantiations of classes. Classes do not represent specific things, while objects represent specific things. class people:

... def speak(self) :

...

print
("hello!")
...'''
Define a people class and define a speak method, but there is no Define attributes,

Because attributes do not belong to classes, but belong to instances of each class.

So we can set different attributes for each instance. ##'''

>>> class people:         #Class  

...   def speak(self):       #Method        

...         print ("hello!")        

. ..

>>>
>>> jack = people() #Create jack instance
>>> tom = people() #Create tom instance
>>> import tab #Import table key function module
>>> jack. #Enter jack., you can see the following method
jack.class jack.doc jack.
module
jack.speak(
>>> jack.speak() #Quote speak method
hello!
>>> jack.age=39 #Add age attribute>>> jack.height
=120 #Add height attribute
>>> jack.
jack.class jack.module jack.height
jack. doc jack.age jack.speak( >>> jack.height120
>>> jack.age
39
'''

#Initialize the object

When creating a class, you can define a specific method named init(). This method will be run as long as an instance of this class is created

. You can pass parameters to the init() method.

In this way, you can set the properties to the values ​​you want when creating the object.

The init() method will complete the initialization when creating the object.

'''
>>> class peo:
... def init(self,name,age,sex):
... self.Name = name
... self.Age = age
... self.Sex = sex
... def speak(self):
... print "my name" + self.Name
. ..
>>>
When instantiating an object of this class:
>>> zhangsan=peo("zhangsan",24,'man')
> >> print zhangsan.Age
24
>>> print zhangsan.Name
zhangsan
>>> print zhangsan.Sex
man
# ----------
>>> print zhangsan

'''

To enable print To get out, you have to use the str method

str(). This method tells python what content to display when printing an object.

'''
#! /usr/ bin/python
class peo:
def init(self,name,age,sex):
self.Name = name
self.Age = age
self.Sex = sex
def speak(self):
print "my name" + self.Name
def str(self):
msg='my name is: ' +self.Name+ ","+ "my age is: " + self.Age +','+ "my sex is:" +self.Sex
# msg='my name is: ' +self.Name+ ","+ "my age is: " + str (self.Age) +','+ "my sex is:" +self.Sex
return msg
shanghai=peo('shanghai','23','man')
# shanghai=peo('shanghai',23,'man')
'''
msg='my name is: ' +self.Name+ ","+ "my age is: " + self.Age +','+ "my sex is:" +self.Sex

Here 23 is the age, but it is converted into a string because self.Age defines It is a string

If you do not escape 23, an error will be reported

If you want to escape it in advance in the program, you need to use str(self.Age)

' ''
print shanghai

'''
The formal parameter self has been used many times before
A class is like a blueprint. Using one class can create multiple object instances,# When the ##speak() method is called, it must know which object called it.

The self parameter here will tell which object the method is called. This is called an instance reference.

zhangsan. speak() is like writing peo.speak(zhangsan)
'''

The above is the detailed content of Comprehensive understanding of classes, objects, methods, and attributes in python. For more information, please follow other related articles on the PHP Chinese website!