Variables.md

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The coding in this course will be done in Jupyter Notebooks. Follow these steps to create your first Jupyter Notebook.

Variables

Variables are like boxes; they hold important information, or data. A variable can hold different data types, such as numbers or words.

Think of a chest. You can store items inside it, and give the chest a name to help you remember what you put in there.
In this case, you'll store some doughnuts in the chest. If you want to remember how many doughnuts you put in the chest, you could name it:
number_of_doughnuts
The chest's name is the variable's name!
Note: When you're writing the name of a variable in Python, it should always be lowercase, with words separated by an underscore.

Initialize Variables

After naming a variable, you can give it a value, which is like filling the chest. This is called initializing.
Say you have three doughnuts in your chest. You'd initialize your chest variable by setting it equal to three:
number_of_doughnuts = 3

Print Variables

To see the value of your variable when you run your program, you'll need to print it.
Type:

number_of_doughnuts = 3
print("number_of_doughnuts is " + number_of_doughnuts"!")

Strings

Variables can hold data besides numbers, including words. Programmers refer to variables holding words as strings.

doughnut_name = "Kepler" 
print(doughnut_name)

Escape Characters

These characters can be used to help format string output.

• \n - new line
• \t - tab
• \" - quotation

Tip: You can make a multi-line string with three quotation marks. You won't need \n characters with this option!

my_multiple_line_string = """This is the first line
This is the second line
This is the third line"""

Boolean

You can also use variables to show if something is true or false; this type of data is called a boolean.
Create a variable to determine if these doughnuts exist.
Add the following to your program and then run it:

doughnuts_exist = True
print(doughnuts_exist)

To set it to not true, change the variable to:

doughnuts_exist = False

Recap

Use variables to store different types of data to use later in your program. Types of data:

number_variable = 5

string_variable = "value"

boolean_variable = True