Introduction to Python Programming

Introduction to Python Programming

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Updated on Oct 3, 2023 12:05 IST

Welcome to the world of Python, where indentation matters more than your opinion! If you’re new to programming, don’t worry – Python is like a pet snake. It won’t bite you (unless you ask it to), and it’s always happy to see you. And if you’re already a seasoned programmer, you’ll find that Python is like a Swiss Army Knife – it has all the tools you need, and it fits neatly in your pocket (or your computer).

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Python is a language that’s all about the whitespace – forget those pesky semicolons and curly braces. With Python, your code is like a snow-covered landscape, waiting for you to leave your footprints in just the right places. But be careful where you step – one misplaced indentation and your code could come crashing down like a house of cards. Luckily, Python comes with a built-in safety net – unless, of course, you’re in the middle of debugging, in which case all bets are off. And when it comes to loops, Python is your trusty friend. But be warned – infinite loops can be like a merry-go-round that never stops spinning. With Python, your programming journey is guaranteed to be anything but boring – except, of course, when you find yourself trapped in an infinite loop.

In the previous article, we took a deep dive into the theory of what is Python. It’s not just a language – it’s a lifestyle. Pythonistas around the world have adopted the Zen of Python as their guiding principles. And what are those principles, you ask? Well, they’re a series of aphorisms that remind us to keep our code simple, readable, and explicit. It’s like a mantra – repeat after me: “Beautiful is better than ugly. Explicit is better than implicit. Simple is better than complex.” And if you’re still not convinced, just remember – with Python, you can do anything from analyzing data to automating your morning coffee. So sit back, relax, and let Python do the heavy lifting. You’ll be amazed at what you can accomplish with just a few lines of code.

Getting Started with Python: Installing Python

To get started with Python, you’ll need to install the Python interpreter on your computer or simply start with Google Colab or Kaggle Notebook. Here’s a step-by-step guide to installing Python on your local system:

To install Python, head to python.org and download the latest version for your operating system. Follow the installation prompts and make sure to add Python to your system’s PATH so you can run Python commands from the command line.

Once you have Python installed, you can choose an Integrated Development Environment (IDE) to write and run your Python code. PyCharm and Jupyter Notebook are two popular options.

To install PyCharm, go to jetbrains.com/pycharm and download the free Community Edition. Follow the installation prompts and then create a new Python project in PyCharm to begin writing and running your code.

To install Jupyter Notebook, use the pip package manager that comes with Python. Open the command prompt or terminal and enter “pip install jupyter” to install Jupyter Notebook on your computer. To launch Jupyter Notebook, enter “jupyter notebook” in the command prompt or terminal. This will open Jupyter Notebook in your web browser where you can create new notebooks and start writing and running your code.

That’s it – you’re ready to start coding in Python with your favorite IDE!

Python Syntax

Python’s syntax is intentionally simple and user-friendly, making it easy to learn and understand. Think of it like learning a dance – once you know the steps, following along is a breeze.

Writing Hello World Program in Python

 
print("Hello World!") //it's this simple.
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Feeling adventurous, eh? Well, whip out your Python interpreter and let’s have some fun. Curious about what happens when you try to add an int to a list? Don’t waste time pondering, just throw it at the interpreter and watch the sparks fly. (Okay, maybe not actual sparks, but you get the idea.) Get ready to embrace your inner Python nerd and let the interpreter be your guide. It’s like a choose-your-own-adventure book, except the only choice you need to make is which code snippet to type next.

How to Run your Python code?

To execute a Python program, you need to follow these steps:

  1. Write your code in a text editor or an Integrated Development Environment (IDE) like PyCharm, Visual Studio Code, or Spyder.
  2. Save the file with a .py extension (e.g., my_program.py).
  3. Open a command prompt or terminal window and navigate to the directory where your program is saved.
  4. Type the command “python” followed by the name of your program file (e.g., python my_program.py).
  5. Press Enter to execute your program.

Alternatively, you can also execute your program by opening it in an IDE and clicking on the “run” button.

Once your program is executed, the Python interpreter reads your code line by line and performs the actions specified in your code. If there are any errors in your code, the interpreter will raise an error message indicating the location of the error.

What is a .py file in Python?

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A .py file is a file written in Python programming language that contains code written in plain text format and saved with a .py extension. When you open a .py file, you can see the code structured in a readable way for both humans and machines. It is organized into functions, classes, and other blocks of code, each with its own purpose and functionality.

NOTE: The .py file must have correct syntax and be free of errors for it to execute correctly. Any errors in the code can prevent the program from running or produce unexpected results. Therefore, it is crucial to test and debug your code before executing it.

Try out these on your Python Interpreter

 
# This is a comment
print("Let's have some fun with Python!")
# Declare a variable and assign it a value
x = 42
# Print the variable value
print("The value of x is:", x)
# Add two numbers
print(20+10)
# Add a string and an integer (this will result in a TypeError!)
print("The answer to life, the universe, and everything is " + x)
# Divide by zero (this will result in a ZeroDivisionError!)
y = 0
print(x/y)
# Use an undefined variable (this will result in a NameError!)
print(z)
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Fun: Check the Output

Q. Which of the following will result in a syntax error when using the print function in Python?

A) print(“Hello world!”)
B) print(“The answer is”, 42)
C) print(“The answer is ” + 42)
D) print(“The answer is”, str(42))

Answer: C) print(“The answer is ” + 42) will result in a syntax error because the + operator cannot concatenate a string and an integer without first converting the integer to a string.

Python Basics

Concept Description Example
Variables A named container used to store data values x = 5
Data Types The type of data that can be stored in a variable x = 5 (integer), y = “hello” (string), z = 2.5 (float), a = True (boolean)
Operators Symbols used to perform operations on data (addition), – (subtraction), * (multiplication), / (division), ** (exponentiation)
Conditional Statements Used to execute different actions based on different conditions if x > 0: print(“x is positive”)
Loops Used to iterate over a sequence of elements for i in range(0, 5): print(i)
Functions A block of code that performs a specific task and can be called upon when needed def greet(name): print(“Hello, ” + name)
Modules A file containing Python code that can be imported and used in other programs import math

Python Data Types

Python offers a wide range of data types, including strings, lists, and dictionaries. Each data type has its unique characteristics, such as being mutable or immutable and ordered or unordered.

But don’t worry – Python comes with plenty of built-in functions and methods to help you manipulate your data effortlessly, acting like your personal assistant.

Whether you’re dealing with an ordered list or an unordered set, Python has got you covered. So put on your dancing shoes and get ready to waltz with Python’s syntax and data types – it’s a piece of cake!

Data Type in Python Description Examples
Integer (int) Whole numbers 42, -3, 0
Float Numbers with decimal points 3.14, -0.5, 2.0
Boolean (bool) Logical values representing True or False True, False
String (str) Sequence of characters “hello”, ‘world’, “123”
List Ordered collection of values [1, 2, 3], [“apple”, “banana”, “cherry”]
Tuple Immutable ordered collection of values (1, 2, 3), (“apple”, “banana”, “cherry”)
Set Unordered collection of unique values {1, 2, 3}, {“apple”, “banana”, “cherry”}
Dictionary Unordered collection of key-value pairs {“name”: “John”, “age”: 30, “city”: “New York”}

Popular Python Course Providers:

Top Python Courses by Udemy Popular Python Courses by Coursera
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Conclusion

In our next blog we will learn about several other Python concepts such as functions, flow control, and OOPs. However, before we can grasp those notions, we must first master the fundamentals. Check out these Python Projects for Beginners and strengthen your fundamental.

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