Python for Developers

Learn to Develop Efficient Programs using Python

Mohit Raj

• Publisher: BPB Publications
• Year: 2019
• ISBN:
  9788194401872
• Topic: Computer Science
• Subtopic: Programming in Python
• Index: Computer Science

Master python programming language in easy steps Key Features

• Start from basics of Python
• Control statement, loop structure, break, continue, and pass statement
• Detailed description of Python data types: string, tuple, list, and dictionary with the help of example
• Organizing code using function, modules, and packages
• Saving text and complex data in text, pickle, and JSON files
• Learn the use of time and time zones
• Parallel execution with the help of threading, multiprocessing, and subprocessing
• Helpful modules for industry
• 
  Description
  It is said that learning Python is easy, but if a learner did not get the right path, then things can get complicated. This book is designed in such a way that you start from basics, followed by advance levels and then move on to some industry-related modules. The initial chapters are written in a simple manner; some chapters are of advance level. Start from the data structure of Python, such as string, list, tuple, and dictionary. The function and module chapter will let you know how to organize a large code. The built-in functions and modules like collections will give you greater flexibility to write efficient codes. The "time" chapter is very important when we deal with time-related things. The mid-chapter contains the advance chapters such as regular expressions, interaction with OS, and multithreading. These chapters are helpful when we want to search the pattern, run the OS commands, and execute the program in parallel. The last chapters are specially designed from an industry point of view. In order to ensure a high quality of code, we use config-parser to avoid hard-coding and logger to log the events. In the multiprocessing and subprocess chapter, you will learn creation, execution, and communication between the processes. What will you learn
  Python for developers is created by taking beginner and intermediate programmers. The book starts from scratch and takes you to the advanced level. After learning advance levels, you will learn parallel programming using multithreading, multiprocessing, and sub-processing. The book will provide information on modules which will be helpful form industry perspective. The book also contains the question for the preparation of the interview. You will also learn the difference between Python 2.7 and Python 3.7. Some of the chapters include an advance part, which will give an in-depth knowledge of the chapters. Who this book is for
  This book is for whoever wants to learn Python and aspires to become a developer or work on projects. Beginners can read this book easily; however, a little knowledge about the programming concepts would be helpful. Basic knowledge of computers would suffice. Table of Contents
  1. Introduction to Python
  2. Python Operators
  3. Control statements and loop
  4. Strings
  5. List and tuple
  6. Dictionary and sets
  7. Functions
  8. Modules
  9. Exception handling
  10. File handling
  11. Collection
  12. Random modules and built-in function
  13. Time
  14. Regular expression
  15. Operating system interfaces
  16. Class
  17. Threads
  18. Queue
  19. Multiprocessing and Subprocess
  20. Useful Modules
  About the Author
  Mohit ([email protected]) is a Python programmer with a keen interest in the field of information security. He has completed his Bachelor's degree (B.tech)in Computer Science from Kurukshetra University, Kurukshetra, and a Master's in Engineering (2012) in Computer Science from Thapar University, Patiala. He is a CEH, ECSA from EC-Council USA. He has worked in IBM, Teramatrix (Startup), and Sapient. LinkedIn Profile: https://www.linkedin.com/in/mohit-990a852a/
  

CHAPTER 1

Introduction to Python

When it comes to rapid development, one language that always comes to mind is the Python programming language. Sometimes, people come up with great ideas, but they are unable to implement it, due to the complexity of the languages learned in the academics. Python has gained a lot of market attention recently. I always say, programming in Python is like programming at the speed of thinking. Python syntaxes are like English syntaxes. According to the IEEE spectrum ranking of 2017 and 2018, Python got the first rank, although different languages have different needs and different domains of interest. But the IEEE spectrum chose Python, which rules the roost. Their selection criteria is described on their website: https://spectrum.ieee.org/static/ieee-top-programming-languages-2018-methods.

Structure

• What is Python
• Python installation
• Basic Python syntax

Objective

With this chapter, you will start your journey to Python programming. You will learn how to install the Python software on Windows, as well as on Linux. After that, you will write your first program. You will learn the significance of triple quotes and the escape sequence. At the end of the chapter, you will see the formatted output.

What is Python?

Python is a general-purpose, high-level language that is used to solve modern-day, computer problems. These days, people have a misconception about Python. They think python is data analytics and machine learning language. However, Python is actually a general-purpose, programming language. Guido van Rossum invented the Python programming language in the early 1990s.

Where is Python Language used?

The better question to ask would be, what is Python NOT used for. Please see below the demanding fields, where Python is being used.

• Data science
• Machine learning
• Web application development
• Network monitoring
• Game development
• Natural language processing
• IoT

Top companies using Python:

The following companies are using Python in their projects:

• Google
• Facebook
• Instagram
• Spotify
• Quora
• Netflix
• Dropbox
• Reddit

Reasons to choose Python

There are many reasons you should use Python.

Multi-purpose

Python is a multipurpose language. The developers are using python Data Analytics, Machine Learning, AI, Web Application, Network Monitoring, ETL scripts, Hacking, and much more.

Vast library and module support

Python comes with a huge community support. There are different libraries and modules that are available in Python for two different purposes as shown in the following table:

Field	Library, Module, Framework
Data analytics	Numpy, scipy, scikit learn
Deep learning	Pytorch, TensorFlow
Network Hacking	Scrapy
Web scrapping	Scrapy
Natural language programming	NLTK
Web application	Django, Flask
Multiprocessing	Celery

Table 1.1

Readability

Python code is easy to read and understandable. It does not contain big syntax, like Java. Python uses indentation to manage the blocks of code, so indentation is the indispensable part of python programming. With indentation, the code becomes easy to read. Python’s syntax is human readable and concise. As a novice, this will help you pick up the fundamentals quickly, with less mental strain, and level up to advanced topics faster.

Object-Oriented

Python has the power of object-oriented programming (OOPS), although you can write the program without defining any class. Whereas it is mandatory to use OOPS in Java, Python offers object-oriented programming as an option, if you are comfortable with OOPS, then choose it, else it can be avoided.

Platform independent

Python codes are platform-independent; it is a matter of copy and paste.

Python is dynamically typed and strongly typed

In dynamically typed, the data-type of a variable is interpreted at run time. In Python, there is no need to define the data-type like int, float, and such others. the following example shall provide more clarification about a variable:

>>> a = 10

>>> type(a)

<class ‘int’>

>>> b = 10.9

>>> type(b)

<class ‘float’>

>>>

In strongly typed, the type of variable does not change at run time. If a = 10, then it remains 10 throughout the execution, until we reassign the variable.

Python installation

Python comes up with two versions, Pytho...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• Dedication
• About the Author
• About the Reviewers
• Acknowledgement
• Preface
• Errata
• Table of Contents
• 1. Introduction to Python
• 2. Python Operators
• 3. Control Statement and Loop
• 4. Strings
• 5. Tuple and List
• 6. Dictionary and Sets
• 7. Function
• 8. Module
• 9. Exception Handling
• 10. File Handling
• 11. Collections
• 12. Random Modules and Built-in Function
• 13. Time
• 14. Regular Expression
• 15. Operating System Interfaces
• 16. Class and Objects
• 17. Threads
• 18. Queue
• 19. Multiprocessing and Subprocess
• 20. Useful Modules