1.3 - Variables

Variables are stored data that can change. You can use them in operations, such as multiplying, dividing, etc. To define a variable, you can use an equals sign to assign the variable to a value.

x = "Hello"
language = "Python"
cool_number = 12345

Variables can contain any type of data, including strings and numbers.

Variable names have a set of rules. Variable names have to:

• Start with a letter or underscore. That means that variable names cannot start with a number.
• Only contain alphanumeric characters and underscores. (A-Z a-z 0-9 _)
• Variables can't be named any Python keywords, such as print

Let's try printing a variable. We must define the variable first, then we can use it.

my_variable = "Hello"
print(my_variable)

print("my_variable") # Notice how this will literally print "my_variable"

Notice how there are no quotes around the text in the print. This is because quotes refer to literal text, and we're trying to print the variable's data, not the literal string "my_variable".