Python Programming for Lazy Beginners: A Simple and Easy Tutorial

CHAPTER 2

Variables: Let Python Do the Memory Work

"Programs must be written for people to read, and only incidentally for machines to execute." — Harold Abelson and Gerald Jay Sussman

Great! In this chapter, we'll be discussing the concept of variables in programming and how they work in Python.

First, we'll learn that variables are used to store values in a program, such as numbers, text, or any other type of data that the program needs to work with. We'll see how to declare a variable in Python using the equals sign (=).

We'll then move on to understand how Python uses memory to store variables. We'll learn that when you declare a variable, Python reserves a certain amount of memory to store the value associated with that variable. We'll also see that the size of this memory depends on the type of data being stored.

The next topic we'll cover is the different data types available in Python, such as integers, floating-point numbers, strings, and Boolean values. We'll learn how to declare variables of each data type and give examples of how to use them in programs.

We'll then move on to manipulate variables in Python. This includes performing mathematical operations on numerical variables, concatenating strings, and using comparison operators to compare values.

Finally, we'll discuss variable naming conventions in Python. We'll learn that variable names should be descriptive and follow certain conventions, such as starting with a lowercase letter and using underscores to separate words in a name.

By the end of this chapter, you'll have a solid understanding of variables in Python, including how they are declared, stored in memory, and manipulated. You'll also learn important programming concepts, such as data types and naming conventions, that are essential for writing clean, readable code.

Variables in python

Certainly! In Python, a variable is a way to store a value so that it can be used later in the program. Variables can store all sorts of data types such as numbers, strings, lists, and more.

To create a variable in Python, you simply need to give it a name and assign it a value using the equal sign =. For example, if we wanted to create a variable called my_variable and assign it the value of 5, we would write:

my_variable = 5

Once we have created a variable, we can use it throughout our program to perform different operations. For example, we can add two variables together:

x = 10
y = 5
z = x + y

In this example, we have created two variables x and y, assigned them values of 10 and 5, respectively, and then created a third variable z that holds the sum of x and y.

Python also allows us to manipulate variables in a variety of ways. For example, we can perform mathematical operations on numerical variables or concatenate strings. We can also use comparison operators to compare the values of variables.

It's important to note that Python is a dynamically typed language, which means that variables don't need to be explicitly declared with a type like in some other programming languages. Instead, Python determines the type of a variable based on the value that is assigned to it.

Overall, variables are an essential part of programming in Python and allow us to store and manipulate data throughout our programs.