Variables: Examples and explanations of Python variables.

Introduction

In programming, a variable is a container that holds a value. The value can be a number, text, or any other type of data. Variables are useful because they allow you to store and manipulate data in your programs.

Naming Variables

To create a variable in Python, you first need to give it a name. The name of a variable should be descriptive and meaningful. It should also follow a few rules:

The name can only contain letters, numbers, and underscores.
The name cannot start with a number.
The name should not be a Python keyword, such as if, else, or for.

Here are some examples of valid variable names:

python

age = 42
name = “John”
is_student = True

Assigning Values to Variables

After you have named your variable, you can assign a value to it using the equal sign (=). Here are some examples:

python

x = 10
y = 3.14
z = “Hello, World!”

In the first example, x is assigned the value 10. In the second example, y is assigned the value 3.14. In the third example, z is assigned the value "Hello, World!".

Data Types

Python has several data types, including:

Integer (int): A whole number, such as 42.
Float (float): A decimal number, such as 3.14.
String (str): A sequence of characters, such as "Hello, World!".
Boolean (bool): A value that is either True or False.

When you assign a value to a variable, Python automatically determines its data type based on the value. For example, in the following code, x is an int and y is a float:

python

x = 10
y = 3.14

Printing Variables

To see the value of a variable, you can use the print() function. Here’s an example:

python

age = 42
print(age)

This will output 42 to the console.

Changing Variable Values

You can change the value of a variable by assigning a new value to it. Here’s an example:

python

age = 42
print(age) # Output: 42

age = 43
print(age) # Output: 43

In the first print() statement, age is 42. After assigning a new value of 43, the second print() statement outputs 43.

Conclusion

Variables are an essential part of programming in Python. They allow you to store and manipulate data in your programs. By following the rules for naming variables and assigning values to them, you can use variables to create powerful and flexible code.