Basic operation of attributes in Python object-oriented programming

In object-oriented programming, properties and methods are used very frequently. The following is a simple summary of the basic operation of the attribute.

In Python oop, attributes are typically manipulated in the following ways:

1, add attributes

2, modify the value of the property

3, get the value of the property

4, delete properties

Use a simple demonstration code to illustrate:

Class DemoClass:

Pass

obj = DemoClass ()

# Add new Attribute

Obj.value = 123

# get the value of attribute

Print (Obj.value)

# Modify the value of

Obj.value = 456

Print (Obj.value)

# Delete Attribute

Del Obj.value

Try

Print (Obj.value)

Except

Print ("error")

In the above code, each annotation explains what the corresponding operation means. In the above code, a simple demonstration of the properties of the Add, modify, get the value and delete several operations. The deleted property is definitely inaccessible, so a try statement avoids the error that might be thrown.

The results of the procedure are as follows:

Grey@desktop-3t80npq:/mnt/e/01_workspace/02_programme_language/03_python/03_oop/2017/08$python attr_demo.py

123

55W

Error

From the above results, roughly do the following summary:

1, directly to the object plus a property assignment operation, if the property does not exist will create a new property;

2, for the object's property assignment operation, if the property already exists, will modify the operation;

3, the property of the numerical acquisition, similar to the C language data structure;

    4, the corresponding information cannot continue to be referenced after the property has been deleted.