Python Fundamentals for Beginners

This guide covers a few Python fundamentals: variables, common data types, collections, and basic operations. Each section includes a small example you can run and change.

Getting started with Python

Before working through the examples, make sure Python is installed on your computer. In this video, I show how to install Python while using the NVDA screen reader.

Variables

A variable gives a name to a value so you can use that value later. For example:

age = 25
name = "John"

Here, age refers to the integer 25, and name refers to the string "John". Python determines the type from the value you assign.

Data types

Python includes several built-in data types. These examples cover a few you will use often.

Numbers

Two common numeric types are integers (int) and floating-point numbers (float).

num_int = 10
num_float = 3.14

The num_int variable holds an integer, while num_float holds a floating-point number. These data types are used for mathematical operations and calculations.

Strings

Strings are sequences of characters used to store text.

message = "Hello, World!"

The message variable contains the string "Hello, World!". Strings can be manipulated in various ways, such as concatenation, slicing, and formatting.

Collections

Python provides several built-in data structures to store collections of items. The most commonly used are lists and dictionaries.

Lists

Lists are ordered collections that can store multiple items.

my_list = [1, 2, 3, 4, 5]

You can access elements in a list using indexing, and they are mutable, meaning you can modify them:

my_list[0] = 10  # Changing the first element to 10

Dictionaries

Dictionaries use key-value pairs to store data.

person = {'name': 'John', 'age': 25, 'city': 'New York'}

Access a value by using its key:

print(person['name'])  # Output: John

Basic operations

Python includes operators for working with data. Here are two basic examples.

Arithmetic operations

Python supports standard arithmetic operations like addition, subtraction, multiplication, and division.

result = 10 + 5

The result variable holds the sum of 10 and 5.

String operations

Strings support various operations, including concatenation and slicing.

first_name = "John"
last_name = "Doe"
full_name = first_name + " " + last_name

Here, full_name combines the values of first_name and last_name with a space in between. You can also slice strings to extract parts of them:

greeting = "Hello, World!"
print(greeting[0:5])  # Output: Hello

What to practice next

Run each example, change the values, and listen to the output. Then combine the concepts by creating a dictionary for a person, putting several dictionaries in a list, and printing one value from each item. That small exercise uses variables, strings, numbers, lists, dictionaries, and indexing together.