Variables and Types

Variables and Types

Variables are a way to store a piece of data. Variables are a fundamental part of Python, as they are with any programming language. Variables have two components to them, the name and its value. Let's start by creating one.

Declaration

Declaring a variable is incredibly simple in Python. It looks like this:

	
    x = 1
    y = "sabe.io"
    print(x)
    print(y)
	
	
    1
    sabe.io
	

Variables in Python are created by simply setting their values, that's it. Unlike in other programming languages, you do not need to specify the type of variable, it is done automatically for you.

Variable Naming Rules

Here are the rules for what are valid Python variable names:

  • The variable name must begin with a letter or underscore
  • The variable name cannot being with a number or symbol
  • Throughout the entire variable name, it can only contain alpha-numeric characters with the only exception being underscores

With that in mind, here are some examples of valid Python variable names:

	
    apples
    _apples
    _apples_
	

And here are examples of invalid Python variable names:

	
    1apples
    app les
    $apples
    %apples
	

Data Types

Python supports five standard data types. We've already seen two of them already, Numbers and String. Here is the entire list:

  • Numbers
  • String
  • List
  • Tuple
  • Dictionary

It is useful to know that you can get the type of a variable by using the type method, like so:

	
    x = 1
    y = "sabe.io"
    print(type(x))
    print(type(y))
	
	
    <class 'int'>
    <class 'str'>
	

We'll get into lists, tuples, and dictionaries in later lessons.