Book Image

Learn Python in 7 Days

Book Image

Learn Python in 7 Days

Overview of this book

Python is a great language to get started in the world of programming and application development. This book will help you to take your skills to the next level having a good knowledge of the fundamentals of Python. We begin with the absolute foundation, covering the basic syntax, type variables and operators. We'll then move on to concepts like statements, arrays, operators, string processing and I/O handling. You’ll be able to learn how to operate tuples and understand the functions and methods of lists. We’ll help you develop a deep understanding of list and tuples and learn python dictionary. As you progress through the book, you’ll learn about function parameters and how to use control statements with the loop. You’ll further learn how to create modules and packages, storing of data as well as handling errors. We later dive into advanced level concepts such as Python collections and how to use class, methods, objects in python. By the end of this book, you will be able to take your skills to the next level having a good knowledge of the fundamentals of Python.
Table of Contents (18 chapters)
Title Page
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
2
Type Variables and Operators

The private variable


Python doesn't have real private methods, so two underlines at the beginning make a variable and a method private. Let's see a very simple example:

class A:
     __amount = 45
    def __info(self):
        print "I am in Class A"
    def hello(self):
        print "Amount is ",A.__amount
a = A()
a.hello()
a.__info()
a.__amount

In the preceding program, __info() is the private method and __amount is the private variable. Let's see the output:

Output of program private1.py

You can see the benefit of the private variable. Outside the class, you cannot access the private method as well as the private variable, but inside the class, you can access the private variables. In the hello() method, the __amount variable can be accessed as shown in the output (Amount is printed).

However, you can access private variables and the private method from outside the class. Use the syntax like instance _class-name__private-attribute.

Now, let's rewrite the program with the correct syntax:

class...