Python Classes and objects - Formula Sheet

Syntax and Rule Cheat Sheet

This chapter does not contain mathematical formulas, but the following are the critical syntax structures and rules governing Python classes and objects:

Class Definition

The standard syntax to define a class block:

class ClassName:
    class_variable = value
    def method_name(self, parameters):
        statements

Object Instantiation

The process of creating an object instance:

object_name = ClassName(arguments)

Constructor Definition

Defining an initialization constructor:

def __init__(self, parameters):
    self.instance_variable = parameter_value

Destructor Definition

Defining a destructor to release class resources:

def __del__(self):
    statements

Member Access

Accessing variables and invoking methods of an object:

object_name.variable_name
object_name.method_name()

Private Attribute Declaration

Declaring a private variable within a class:

__variable_name = value