Introduction to Python

Tutorial 1 of 5

Introduction

Goal of the Tutorial

This tutorial aims to introduce you to the basics of Python programming. By the end of this tutorial, you will have a solid foundation in Python, and you will be comfortable with the Python development environment and essential Python syntax.

What You Will Learn

In this tutorial, you will learn:

  • How to set up the Python development environment on your computer
  • The basics of Python syntax
  • How to work with variables, loops, and conditional statements in Python
  • How to write functions in Python
  • How to handle errors in Python

Prerequisites

No prior programming knowledge is needed for this tutorial. All you need is a computer and an internet connection to download the necessary software.

Step-by-Step Guide

Python Development Environment

To start coding in Python, you need to set up the Python development environment on your computer. This involves installing Python and a code editor or Integrated Development Environment (IDE).

You can download Python from the official Python website.

For the IDE, there are many options available, but for beginners, Thonny or PyCharm is recommended.

Python Syntax

Python syntax refers to the set of rules that define how a Python program will be written. Python was designed to be very readable, which makes it a great language for beginners.

Python Variables

Variables in Python are created the moment you assign a value to it. For example:

name = "John"
age = 25

In this example, name and age are variables.

Python Loops

Python has two types of loops - for and while.

A for loop is used for iterating over a sequence (that is either a list, a tuple, a dictionary, a set, or a string).

fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
  print(fruit)

A while loop can execute a set of statements as long as a condition is true.

i = 1
while i < 6:
  print(i)
  i += 1

Python Conditional Statements

Python supports the usual logical conditions in mathematics:

  • Equals: a == b
  • Not Equals: a != b
  • Less than: a < b
  • Less than or equal to: a <= b
  • Greater than: a > b
  • Greater than or equal to: a >= b

These conditions can be used in several ways, most commonly in "if statements" and loops.

Code Examples

Python Variables

# This is a comment
# Comments in Python start with the hash symbol

# creating variables in Python
name = "John" # a string variable
age = 25 # an integer variable

# printing variables
print(name) # outputs: John
print(age) # outputs: 25

Python Loops

# Python for loop example
fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
  print(fruit)
# outputs: 
# apple
# banana
# cherry

# Python while loop example
i = 1
while i < 6:
  print(i)
  i += 1
# outputs: 
# 1
# 2
# 3
# 4
# 5

Python Conditional Statements

# Python if statement example
a = 33
b = 200
if b > a:
  print("b is greater than a")
# outputs: b is greater than a

Summary

In this tutorial, you have learned how to set up the Python development environment, the basics of Python syntax, how to work with variables, loops, and conditional statements in Python.

For further learning, you can explore more complex Python concepts such as functions, error handling, and file I/O.

Practice Exercises

  1. Write a Python program to add two numbers.
  2. Write a Python program that prints all the numbers from 0 to 10 using a for loop.
  3. Write a Python program that prints the factorial of a number. The number should be input from the user.

Solution

# program to add two numbers
num1 = 10
num2 = 20
sum = num1 + num2
print("The sum is", sum) # outputs: The sum is 30
# program to print numbers from 0 to 10
for i in range(11):
  print(i)
# program to print the factorial of a number
num = int(input("Enter a number: "))
factorial = 1
if num < 0:
   print("Sorry, factorial does not exist for negative numbers")
elif num == 0:
   print("The factorial of 0 is 1")
else:
   for i in range(1,num + 1):
       factorial = factorial*i
   print("The factorial of",num,"is",factorial)