Python Class

Python supports Object Oriented Programming (OOP) like many other popular programming languages. OOP revolves around the idea of classes and objects.

A class in Python is a blueprint from which objects can be constructed. Imagine class in OOP as a sketch by an architect for new building construction. Civil Engineers and construction workers then bring this sketch to life by building a real world object i.e. the building in this case.

Naming convention for a Python class is PascalCase. A class can be simply defined as follow in Python:

class NewPythonClass:
	'''A docstring like this explains what the class does'''
	pass

In the example above, a class in Python can be defined using the class keyword followed by the name of the class. We defined a docstring within the class to explain what the class does and why it is implemented. It helps in providing a detailed explanation about a class.

A class in Python has attributes or properties and methods that act on those attributes. There are also attributes and methods that are pre-built into every Python class and they start with two underscores and end with two underscores __. For example, __init__ is a special method that is used to create new objects from the Python class. __str__ is a special method that is used to provide a string representation of the class when objects are created from it.

Objects are created from a class by calling the constructor function which is __init__ by using the name of the class followed by parentheses (). Any attributes that are needed to create objects from that class will be passed within those parentheses.

# python class syntax
>>> class MyPythonClass:
… 	'''this is a docstring to explain what this class does'''
… 	pass
…

>>> class Shape:
… 	'''This is a base class Shape that allows to create shapes of all kinds'''
… 	def __init__(self):
… 		self.type = 'Shape'
… 	def __str__(self):
… 		return "This is a shape of type {}.".format(self.type)
…

# create an object from class Shape
# __init__ will be called while creating new objects
>>> shapeObject = Shape()
>>> print(shapeObject)
This is a shape of type Shape.